Center for Ecological Research, Kyoto University


CER seminars

CER holds a seminar inviting outside people at the lecture room 2 on the third Friday of each month (which may change) except in August and March. In addition, we special hold CER seminars and independent open seminars irregularly. For the CER seminar schedule, please see the CER website.

From 2020, some lectures will be distributed online to registrants outside CER. Online distribution uses Zoom or Youtube depending on the situation (27 April, 2023).

356th 21 June, 2024 (Fri.) 14:00~17:00

Asano Ishikawa (Graduate school of Frontier Sciences, The University of Tokyo)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

A key pleiotropic gene important for the diversification of reproductive seasonality and its ecological function

The annual timing of reproduction is a key life-history trait that greatly affects fitness. Animals often evolve in the timing and duration of reproduction to adapt to the different seasonalities between habitats. However, little is known about the molecular genetic mechanisms underlying interpopulation variations in reproductive seasonality. To address this question, we use the three-spined stickleback, Gasterosteus aculeatus as a model. Transcriptome analysis and genome editing techniques revealed that the thyroid stimulating hormone beta 2 (TSHβ2) gene plays an important role in the diversification of the reproductive timing. Further analyses also demonstrated its pleiotropic functions in multiple molecular pathways and its significant impact on the ecosystem.

Takafumi Katsumura (Kitasato University School of Medicine)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Understanding the molecular mechanism and evolutionary process behind seasonal gut-length plasticity in Medaka (Oryzias latipes)

Many organisms exhibit phenotypic plasticity, changing their traits in response to their environment. Recently, this plasticity could be a "trigger" for occurring novel traits (Plasticity-led evolution hypothesis). However, how plastic traits are genetically defined and spread as heritable novel traits in a population is largely unknown. Thus, we tackled to elucidate the molecular mechanism of plasticity-led evolution and its evolutionary process, focusing on the gut length of medaka (Oryzias latipes), which exhibits seasonal plasticity and genetic polymorphism. This talk will present our recent results showing that plasticity-led evolution in medaka gut-length is an evolutionary process that can be explained within the framework of existing genetics, starting with the loss of CpG sites by nucleotide substitution, followed by the selection and fixation of genetic mutation, and our on-going project.

Special 24 May, 2024 (Fri.) 13:00~

Robert C. Schuurink (University of Amsterdam / Visiting Professor, Center for Ecological Research, Kyoto University)

(Face-to-face presentation in the second lecture room of CER)

Tomato glandular hairs, volatile terpenes and herbivores

Plants are masters in defending themselves with an extensive array of specialized metabolites such as terpenes. These are quite often produced in the glandular cells of hairs that are present on leaves and stems, the glandular trichomes. We have predicted and implicated several trichome-produced terpenes in the protection of tomato against insects. Our interest is, particularly, in the regulation of terpene biosynthesis and in the development of glandular trichomes. Several transcription factors involved in these processes have been identified, some of which are regulated by the defense hormone jasmonic acid. In turn, insects have developed tools to modulate plant defense responses. We focus on the whitefly Bemisia tabaci that feeds from the phloem of the leaf and secretes proteins, so called effectors, in the plant tissue to influence plant defences.We have identified several of these effectors and the plant proteins with which they interact. Potentially these plant proteins are encoded by susceptibility genes that could be targets of new breeding strategies for whitefly resistance. The seminar will also report on this side of the battle.

355th 17 May, 2024 (Fri.) 14:00~17:00

Mieko Kono (Research Center for Integrative Evolutionary Science, SOKENDAI)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

The tripartite symbiosis of the lichen Cladonia vulcani Savicz that drove the adaptation to an extreme environment

Symbiosis has been involved in many evolutionary innovations in the history of life. In lichens, symbiosis has led the expansion of habitats into almost all terrestrial environments. For more than a century, lichens have been considered as a symbiotic association between a fungal partner that constructs a symbiotic structure, and an algal partner that provides photosynthetic products. Recently bacteria and basidiomycete yeasts were found to be associated with a wide range of lichens therefore suggested as a third symbiotic partner. However, so far no essential third partner of lichen symbiosis has been reported. In an attempt to identify the essential third partner, we focused on Cladonia vulcani Savicz, which exclusively inhabits in volcanic regions where organisms are exposed to highly toxic hydrogen sulfide gas. We collected samples across Japan (Hokkaido, Aomori, Gunma, Tochigi, Kanagawa, Kagoshima, and Kumamoto) and investigated constituents of the lichen at the genomic level. As a result, we identified a single bacterium that exists in all the samples in considerable amount. In the bacterial genome, we identified genes involved in the process of using hydrogen sulfide as an energy source. Thus we hypothesize that the symbiosis with this bacterium enabled the adaptation to the hydrogen sulfide-rich environment. In this seminar I will discuss how has the extreme environment affected the relationships of the three partners and how has the tripartite symbiosis distributed across volcanic regions in Japan by introducing the results of our genomic analyses.

Sakumi Iki (Center for the Evolutionary Origins of Human Behavior, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Evolution of play and curiosity

Many mammalian species, including humans, engage in play. Nonetheless, in the animal kingdom as a whole, play is exhibited by a limited proportion of species. Play is a seemingly nonfunctional behavior with unclear immediate benefits pertaining to survival and reproduction. It has been hypothesized that even if play does not provide an immediate benefit, it provides an opportunity to practice and learn skills required in subsequent stages of life and, in the long run, improves survival and reproductive success. However, the results of studies conducted to test this hypothesis have been inconsistent. If play is essentially a "useless" behavior with little adaptive value, what evolutionary processes led to the emergence of play? This presentation will first review recent empirical studies on the function of play. Subsequently, I will discuss the hypothesis that play evolved as a byproduct of intrinsic exploratory behavior motivated by curiosity, and present some findings from ecological and behavioral studies that favor this hypothesis.

354th 19 April, 2024 (Fri.) 14:00~17:00

Yurie Otake (Center for Ecological Research, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Zooplankton ecology with long-term observation data: retrospective analysis with lake sediments and attempt for present and future long-term monitoring

Wataru Nakamura (Atmosphere and Ocean Research Institute, The University of Tokyo/The Lake Biwa Environmental Research Institute)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Mechanisms of long-term carbon sequestration in the soil and in the ocean by mangroves as a countermeasure to climate change

353rd 16 February, 2024 (Fri.) 14:00~17:00

Michael A. Huffman (Wildlife Research Center, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

My Sri Lankan primate research - past, present and future prospects

For the last 18 years, in close collaboration with Sri Lankan and Japanese colleagues, I have been conducting primatological research in Sri Lanka, on the toque macaque (3 sub-spp.), grey langur (1 sub-sp.), and purple-faced langur (4 sub-spp.). The island is one of South Asia's biological diversity hotspots, with a diverse range of eco-climatic habitats ranging from lowland rainforests and mountainous highland cloud forests reaching 2,400 m asl to lowland arid savannas and woodlands. The ecological and biological diversity of the island makes Sri Lanka an ideal location for investigating the evolution of sympatric primates and their co-existence with humans. Our research efforts thus far have focused mainly on expanding our knowledge of the island-wide distribution, phylogeography, morphological adaptations to diverse eco-climatic conditions, zoonoses, behavioral ecology, and conservation of these three endemic diurnal primate species. The goal of today's lecture is to introduce the audience to Sri Lanka and its many interesting research opportunities.

Yukako Katsura (Center for the Evolutionary Origins of Human Behavior, Kyoto University)

(Face-to-face presentation in the second lecture room of CER and CER-limited zoom distribution)

Genome and sex chromosome analyses of Japanese frogs carrying both XY and ZW chromosomes within the same species

In the evolution of sex chromosomes, particular attention is given to the poorly understood phenomenon of "sex chromosome turnover." Sex chromosome turnover is defined as the phenomenon where the sex chromosome system changes from XY type to ZW type (or vice versa), or even when different evolutionarily originated sex chromosomes emerge within the same type (e.g., from XY to another XY). The Japanese frog (Glandirana rugosa) inhabiting Japan is a rare species that possesses both XY and ZW sex chromosomes within the same species, and the turnover of sex chromosomes from XY to ZW has been observed. Our research group aims to elucidate at the molecular level how the turnover of sex chromosomes occurs in the frogs. Previously, we determined the nuclear genome of the frog using short read sequencing (Katsura et al., LSA 2021). Furthermore, it has been suggested that sex chromosomes originating from at least three different chromosomes independently emerged within the population (Miura et al., Mol. Ecol. 2022). The frogs have 13 chromosomes, and in two populations (Tokai region and Hokuriku Tohoku region), the chromosome 7 has morphologically differentiated into ZW and XY sex chromosomes, as reported in previous studies. However, in other populations, sex chromosomes do not show morphological differentiation. In addition to presenting the results of sequence comparisons of morphologically differentiated XYZW sex chromosomes, I would like to introduce the findings from our analyses of populations and genome studies in the frogs.

352nd 12 January, 2024 (Fri.) 14:00~17:00

Akane Kubota (Division of Biological Science, Nara Institute of Science and Technology)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Molecular basis of flowering regulation in response to temperature fluctuation under field environment

Proper timing of flowering regulation is one of the important events in plant development. In a long-day plant, Arabidopsis, flowering is promoted by the induction of FLOWERING LOCUS T (FT), which encodes florigen. Despite advances in understanding of the regulatory mechanism of FT, it is not clear how these mechanisms regulate seasonal flowering responses in natural environment. To address this, we established simplified laboratory conditions that reproduce flowering responses observed in natural long-day conditions. By using these conditions, we are trying to understand how daily temperature fluctuation regulates FT expression. In this presentation, I will talk about our resent findings and future perspectives.

Yoshihiro Yoshitake (Graduate School of Biostudies, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Evolution of the photoperiod-dependent growth phase transition mechanisms in land plants

A photoperiodic control of reproductive organ formation is crucial for the plant adaptation. Although the molecular mechanism of photoperiodic flowering has been investigated in model plants such as Arabidopsis and rice, the molecular mechanisms of gametangia formation and their evolutional connection remain still largely unknown. Here, we report that the photoperiod-sensing modules consisting GIGANTEA (GI), FLAVIN-BINDING KELCH REPEAT F-BOX1 (FKF), and CYCLING DOF FACTOR (CDF) are functionally conserved in the bryophyte Marchantia polymorpha. We show that Marchantia CDF directly represses the transcription of BONOBO (BNB), which encodes a transcription factor that controls differentiation of germline cells, by recruiting the corepressor TOPLESS to the BNB promoter. Cistromes based on CDFs in A. thaliana and M. polymorpha, which diversified in the angiosperm and bryophyte lineages, share orthogroups extensively. Our findings indicate that genetic rewiring may have driven photoperiod dependent reproductive phase transition pathway during land plant evolution.

351st 15 December, 2023 (Fri.) 14:00~17:00

Tetsuya Akita (Fisheries Resources Institute, Japan Fisheries Research and Education Agency)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Ecological inference in the recent past based on kinship assignment

Pedigree structure exists in every biological population, meaning that the frequency of kinship relationships contains information about the population, such as population size and life history parameters. In this talk, I will present the use of kinship information to estimate survival, migration rate, and contemporary effective population size, as well as the population estimation theory, known as close-kin mark-recapture (CKMR), that has been developed in the context of fishery stock analysis. I also briefly discuss the theoretical background of methods for distinguishing kinship relationships such as parent-child, sibling, and half-sibling, using from genomic information. Finally, I hope to convey that these theoretical developments are "interesting and useful" studies, which may correspond to reconstructing population genetics in terms of mark-recapture methods.

Takuya Hosoki (Tomakomai Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University)

(Hybrid of face-to-face presentation in the second lecture room of CER and CER-limited zoom distribution)

Toward understanding the robustness to species identity from hybrid genome studies

How do species remain distinct in the face of hybridization? Recent genomic studies have uncovered traces of past hybridization in many organisms; however, how rapidly a mixed genome is reorganized after hybridization and what factors determine the outcome of hybridization remain largely elusive. In this talk, I will introduce an example of hybridization between freshwater Gasterosteus aculeatus and marine G. nipponicus induced by the 2011 Tohoku tsunami. I will then discuss about both intrinsic and extrinsic factors contributing the outcome of tsunami-induced hybridization.

Special 27 November, 2023 (Mon.) 10:00~11:30

Biva Aryal (Tribhuvan University / Visiting Associate Professor, Center for Ecological Research, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Tree diversity, carbon stock and regeneration pattern in Shorea robusta Gaertn. f. forests along the altitudinal gradient in eastern Nepal

The forest with good regeneration can store a sufficient amount of carbon. The Shorea robusta Gaertn. f. (Sal) forests of Nepal are facing the problem of poor regeneration. The present study aimed to find out the tree diversity, carbon stock and regeneration status of Shorea robusta forests along an altitudinal gradient in eastern Nepal. The study was conducted in three community forests of Sunsari and Dhankuta District. The forests were Ramdhuni Kalijhora community forest (82-170 m a.s.l.), Patrangbari community forest (440-695 m a.s.l.) and Khanidada Malbase community forest (650-990 m a.s.l.), which were regarded as lower, middle and upper altitudinal range forest respectively. The stratified random sampling method was used for the sampling. Circular plots of 7m radius were used for the study of trees. However, to study of regeneration, seedlings and saplings were quantified in circular plots with 1m and 3m radius respectively. Altogether, 90 circular plots (30 in each altitude) were laid for trees and saplings and 180 plots were (60 in each altitude) laid for seedlings. The present investigation has recorded 43 tree species under 25 families and 35 genera. The Dominance-Diversity curve showed the highest IVI of Shorea robusta in all three altitudinal ranges. The value of Shannon Diversity index was higher in high altitudinal range (1.07) followed by low (0.96) and middle altitudinal range (0.83). Species richness increased with increasing altitudes. The tree carbon stock ranged from 134 372 t ha-1 .Similarly soil carbon stock was higher in high altitudinal range (60.03 t ha-1) and lower in middle altitudinal range (27.69 t ha-1). The seedling of Shorea robusta was higher in low altitudinal range and lower in high altitudinal range. Contrast results were obtained for sapling i.e. lower in low altitudinal range and higher in high altitudinal range. The regeneration status of seedlings was healthy but poor in terms of saplings. Therefore, the establishment of seedlings to saplings in the study areas was very crucial for the sustainability of forests.

350th 17 November, 2023 (Fri.) 14:00~17:00

Aru Toyoda (Japan Monkey Centre)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

The socio-ecology of the stump-tailed macaque revealed by data-driven research

Goro Hanya (Center for Ecological Research, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distributionn)

Population dynamics of Japanese macaques in the coniferous forest of Yakushima

349th 20 October, 2023 (Fri.) 14:00~17:00

Kenji Suetsugu (Graduate School of Science, Kobe University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Diverse interactions of heterotrophic plants with their hosts, pollinators and seed dispersers

Heterotrophic plants have long captured the attention of researchers due to their unique morphological and ecological attributes. Nonetheless, apart from some knowledge amassed concerning host associations, there is a noticeable lack of reports addressing their life history, particularly pollination biology and seed dispersal mechanisms. In this context, I have elucidated not only unique adaptations to mycorrhizal fungi but also several distinctive pollination and seed dispersal systems that are indirectly influenced by the heterotrophic lifestyle exhibited by these plants. Therefore, in this seminar, I will introduce various interactions of heterotrophic plants with their hosts, pollinators, and seed dispersers.

Shunsuke Matsuoka (Field Science Education and Research Center, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distributionn)

Diversity patterns of ectomycorrhizal fungi evaluated from a community ecology approach

Fungi influence the material cycle and the growthl of interacting organisms through decomposition, mutualism, and parasitism. Although the diversity of fungi is estimated to be several million species, our knowledge of their actual diversity is still limited compared to that of plants and animals. Using a community ecology approach, I have been studying the spatio-temporal patterns and drivers of diversity in ectomycorrhizal fungi. In this seminar, I will first present approaches to studying fungal diversity and findings on the diversity patterns of ectomycorrhizal fungi. Next, I will also introduce the characteristics of the Kyoto University FSERC research forest to which I belong and the research that I have begun to undertake in the research forest.

348th 15 September, 2023 (Fri.) 14:00~17:00

Yukako Hattori (Graduate School of Biostudies, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Deciphering the molecular basis of life's survival strategies

Tomoyuki Hori (Environmental Management Research Institute, AIST)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distributionn)

Understanding and applicaion of microbial communities in natural and engineered environments

347th 21 July, 2023 (Fri.) 14:00~17:00

Yuzou Sano (Research Faculty of Agriculture, Hokkaido University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Scanning electron microscopic studies of structures and functions of woody plant cells

The lecturer has conducted anatomical/functional studies of woody plant cells/tissues by effectively using a scanning electron microscope (SEM). In this seminar, the lecturer talks a few examples of our studies using SEM as well as to briefly explain the principles and capacities of this macroscope. Comparative studies of interfiber pit structures indicated that there were distinct types of interfiber pits and behavior of water greatly differed in newly formed xylem tissues according to the types. In a study to evaluate the influences of environmental stresses to growth of woody plants, we found a special type of storage cell.

Takeshi Izuta (Institute of Agriculture, Tokyo University of Agriculture and Technology)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distributionn)

Effects of ozone on plants

Ozone (O3), a major component of photochemical oxidants, is a gaseous air pollutant that has adverse effects on plants. Ozone in the atmosphere is absorbed into leaves through the stomata. When ozone is absorbed into leaves, reactive oxygen species are produced in the leaves, and physiological functions such as photosynthesis and various metabolic systems are inhibited. Ozone reduces net photosynthetic rate, growth, yield, and quality of edible parts of crops. Photosynthetic capacity and growth of trees are reduced by ozone. In my presentation, I will outline the effects of ozone on plants, and present our recent research and future issues.

346th 16 June, 2023 (Fri.) 14:00~17:00

Hideyuki Doi (Graduate School of Informatics, Kyoto University)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Informatics Approaches on Ecology and Biology

Advancements in informatics techniques, such as simulation, statistical analysis, modeling, and database construction, coupled with progress in observation technologies like high-throughput sequencing, environmental DNA, satellite observation, and automated monitoring, have facilitated the collection of data on a broad geographical and temporal scale in ecology and biology. Moreover, the adoption of an open and database-driven approach, exemplified by GBIF and ANEMONE, enables easier access to large-scale data, thereby unlocking possibilities to address previously unattainable ecological and biological questions. In this seminar, I will present our group's research that leverages various informatics techniques to study biological communities, ecosystem dynamics, and biological hypotheses, while also discussing future approaches to informatics in ecology and biology.

Kenta Suzuki (BioResource Research Center, RIKEN)

(changed to zoom (live) distribution)

Causal inference for time series and information flow in ecosystems

Ecosystems are complex of various biological, physical, and chemical processes, and the data obtained from their observations can be difficult to handle using existing time series-based methods for causal inference. To address this challenge, we proposed EcohNet, a framework based on the predictability of time series, which is implemented by a type of neural network (echo state network) and the progressive selection of its input variables. EcohNet is based on the concept of Granger causality, but has a greater degree of flexibility than other common implementations such as vector autoregression. In this presentation, I would like to introduce EcohNet and overview its relationship with methods based on nonlinear time series analysis (CCM) and information theory (transfer entropy) from the perspective of "information flow" in ecosystems.

Special 12 June, 2023 (Mon.) 15:00~16:00

Matthew Barbour (Universitè de Sherbrooke, Canada)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Eco-evolutionary dynamics in plant-insect food webs

Global change is reshaping biodiversity across scales - from the genetic makeup of populations to the composition of species in ecological communities. These cross-scale changes often unleash an array of indirect effects that make it difficult to predict ensuing ecological and evolutionary responses due to the complex network of interactions species are usually embedded in. In this seminar, I will share a series of field and lab experiments with plant-insect food webs that seek to better understand the interconnected nature of biodiversity across scales. I will begin by showing how genetic variation within species can scale up to influence food-web structure and species coexistence. I will then discuss how the diversity of species in a community can feedback to shape genetic and phenotypic variation in interacting populations. Throughout, I will argue that understanding these eco-evolutionary processes is critical for predicting how biodiversity will be reorganized by environmental change.

Special 8 June, 2023 (Thurs.) 14:00~

Carlos Martínez Núñe (Agroscope, Switzerland)

(zoom (live) distribution)

Olives alive: Effects of agricultural management and landscape complexity on biodiversity and ecosystem services in olive groves

Intensive agriculture is a main driver of biodiversity loss worldwide. With this threat to biodiversity, agricultural systems also face the risk of losing ecosystem services provided by biodiversity. Yet, we still do not know how to efficiently increase biodiversity and ecosystem services in key agroecosystems such as olive groves, one of the most socioeconomically important crop worldwide. In this talk, I will present an overview of the seven main studies produced during my PhD thesis, which aim to understand how agricultural management, landscape complexity, and their interaction affect biodiversity and ecosystem services in olive groves in southern Spain.

345th 19 May, 2023 (Fri.) 14:00~17:00

Koichi Sugimoto (Tsukuba-Plant Innovation Research Center, University of Tsukuba)

(Hybrid of face-to-face presentation in the second lecture room of CER and zoom distribution)

Usefulness of natural variations for gene identification in plant defense

Plants deploy various defense mechanisms against their pests in cope with bunch of herbivores and pathogens. I am interested in the mechanism of this elaborate defense system of plants. Genetic variations and its genetic analyses should be a powerful tool to dig the mechanistic insight of the plant defense.
In this seminar, I would like to introduce a volatile glycosylation phenomenon involved in the volatile mediated plant-plant interactions. We successfully identified the glycosyltransferase gene, which produces a defensive glycoside from the volatile compound emitted from the neighboring plants infested by herbivore. I would also like to discuss our recent progress in the identification of the gene for the formation of trichome, a hair-like defensive structure on the epidermis of plant vegetative tissues. These two projects have been started from the finding of the differences between cultivars and their wild relatives, or differences between ecotypes of wild species. Therefore, I would like to introduce the availability of materials from the bioresource centers.

Masayoshi Uefune (Faculty of Agriculture, Meijo University)

(Hybrid of face-to-face presentation in the second lecture room of CER and CER-limited zoom distribution)

Defense of the liverwort Marchantia polymorpha against herbivores

Recently, induction of defense genes, accumulation of jasmonic acid, increase in salicylic acid, and systemic acquired resistance in mosses infested by pathogens have been reported in studies of their induced defense. How plants evolved their defense against pathogens has been discussed. By contrast, little is known about how mosses defend themselves against herbivores. Knowledge of the defense of mosses against herbivores would be useful in discussing of the evolution of plant defense against herbivores. In this seminar, I will present studies on how the liverwort, Marchantia polymorpha, defends itself against herbivores.

Special 26 April, 2023 (Wed.) 14:00~16:00

Tadashi Fukami (Department of Biology and of Earth System Science, Stanford University)

(Face-to-face presentation in the second lecture room of CER)

Alternative community states and agricultural applications of flower microbes

344th 21 April, 2023 (Fri.) 14:00~17:00

Jotaro Urabe (Graduate School of Life Sciences, Tohoku University)

(Hybrid of face-to-face and zoom distribution in the second lecture room of CER)

Ecological stoichiometry for understanding environmental changes and animal's feeding ecology

Mengqi Jiang (Center for Ecological Research, Kyoto University)

(Hybrid of face-to-face and zoom distribution in the second lecture room of CER)

Changes in relative nitrogen:phosphorus requirements for phytoplankton growth with absolute nutrient levels and their macromolecular basis

343rd 17 February, 2023 (Fri.) 14:00~17:00

Yoko Mitani (Wildlife Research Center, Kyoto University)

(zoom (live) distribution)

Pinnipeds: ecology and behavior of animals living in ocean and land

Pinnipeds are animals with finned limbs belonging to the order Carnivora, which includes the families of Phocidae (true seals), Otariidae (eared seals), and Odobenidae (walruses). They are amphibious mammals that breed, molt, and rest on land and forage in water. They dive and feed on krill, fish, cephalopods, benthic animals, etc. Many species are known to migrate after the breeding and molting seasons, but most females return to their birthplaces. Evolutionarily, pinnipeds are monophyletic and closely related to the family Mustelids, but it is thought that they lived on land until the phylogenetic differentiation of the families Phocidae and Otarioidea (Otariidae and Odobenidae) occurred, and both lineages have entered the marine realm independently. There are many differences between Phocidae and Otariidae, for example, hemispheric sleep, in which half of the brain is asleep and half is awake, has been observed in several species of Otariidae, but not in Phocidae. In this seminar, the ecology and behavior of these pinnipeds will be introduced.

Kodzue Kinoshita (Wildlife Research Center, Kyoto University)

(zoom (live) distribution)

Evaluation of physiological stress in endangered felids using fecal hormone

How do habitat changes affect physiological stress in wildlife? When the external environment changes, hormones were secreted to maintain their homeostasis. I believe that by measuring of hormone concentrations involved in the stress response allows to assess the impact of environmental changes on wildlife. After circulating in the blood, hormones are metabolized in the liver and excreted in feces and urine. Many feline species keep local ecosystems in balance as an apex predator. Most of them are endangered and their population density is low, making direct observation difficult. Therefore, the key is how to obtain information about the defecator from the feces, which are relatively easy to collect. In this seminar, the study on the relationship between environmental changes and physiological changes of feline species evaluated using fecal stress and sex hormones will be presented.

342nd 20 January, 2023 (Fri.) 14:00~17:00

Saori Fujii (Forestry and Forest Products Research Institute)

(zoom (live) distribution)

Untangling the enigma of soil animal diversity by a focus on litter traits related to food and habitat qualities

Kaoru Maeto (Graduate School of Agricultural Science, Kobe University)

(zoom (live) distribution)

Is asexual reproduction of parasitoid wasps an evolutionary dead end?

341st 16 December, 2022 (Fri.) 14:00~17:00

Satoshi Yamamoto (Institute for Agro-Environmental Sciences, NARO)

(zoom (live) distribution)

Genomics of parallel ecological speciation: the allochronic speciation of Inurois punctigera

Parallel speciation is a phenomenon in which the same pattern of speciation occurs in independent lineages. Repeated evolution of the same reproductive isolation in similar environments provides strong evidence that natural selection promotes speciation. However, even in the same situation, some taxa show parallel speciation, while others do not. Therefore, we have to understand factors that allow the divergence of reproductive isolation traits other than natural selection. Here we report that genetic variations established during an old speciation event promoted a second new speciation event using Japanese winter geometrid moths (Inurois punctigera), in which reproductive isolation is caused by differentiation of reproductive timing.

Yasuyuki Nomura (Research Institute for Food and Agriculture, Ryukoku University)

(zoom (live) distribution)

Novel traits of hybrids cause unique population genetic structure

Hybridization is one of the driving forces that produce novel traits. I have been studying cogongrass (Imperata cylindrica) to clarify the role of the novel traits produced by hybridization. There are two types of I. cylindrica. An early-flowering type (E-type) that blooms in April in western Japan has large rhizome aerenchyma and prefers wet soils, while a common type (C-type) that blooms in May has small rhizome aerenchyma and prefers relatively dry soils. Hybrids of these two ecotypes also grow more than their parents, especially in the Tohoku region. Our study revealed that only F1 hybrids exist in this hybrid population. Why are there only F1 hybrids in hybrid populations and why are more F1 hybrids than parents in Tohoku? We thought this was caused by novel traits in F1: (1) a flowering phenology shift from spring to fall and (2) a great phenotypic plasticity of rhizome aerenchyma. In this seminar, I will discuss the impact of these novel traits on the I. cylindrica population.

340th 18 November, 2022 (Fri.) 14:00~17:00

Takefumi Nakazawa (Department of Life Sciences, National Cheng Kung University)

(zoom (live) distribution)

Incorporating an ontogenetic perspective into mutualism: a review of empirical evidence and theoretical models

Ontogenetic variation is the most fundamental biological aspect of an organism, and stage-structured (size-structured) prey-predator relationships have increasingly been studied for a better understanding of food-web dynamics. However, little is known about stage-structured mutualism and its ecological consequences. In this talk, first I synthesize the literature information on stage-structured interactions across different mutualisms (e.g. pollination, seed dispersal, nutritional and defensive) and demonstrates that mutualism is commonly stage-structured in nature. In addition, I briefly overview my recent theoretical studies on the ecological consequences and evolutionary mechanisms of stage-structured mutualism in omnibus form. In conclusion, I suggest that both empirical and theoretical efforts are needed to collect and incorporate individual-level interaction data into community ecology theories. Such research efforts can provide novel insights into biodiversity conservation and ecosystem management, while calling for a paradigm shift in community ecology about the concept of species interaction.

Ryosuke Nakadai (Biodiversity Division, National Institute for Environmental Studies)

(zoom (live) distribution)

Effects of persistence and growth of individual trees in nature and human society

In biodiversity science and related study fields, information on the presence or absence of species and the abundance of each species have been the main focus of research. On the other hand, little attention has been paid to information on individuals which we can observe directly. In my presentation, I will introduce the findings that can be obtained by analyzing the survival and growth of individuals of trees, for which there is more individual information than for other taxa. I will present some case studies on the effects of individual persistence and growth on temporal compositional changes in forest tree communities in the first part of the presentation. In the latter part, I will also present my recent research on the impact of individuals that have persisted and grown for a long time (i.e., giant trees) on human society (e.g., ecosystem services) and the driving factors behind them (e.g., climate, individual size). At the end of my talk, I would like to discuss the usefulness and future directions of individual information in biodiversity science and related fields.

339th 21 October, 2022 (Fri.) 14:00~17:00

Hideki Takahashi (Graduate School of Agricultural Science, Tohoku University)

(zoom (live) distribution)

What do nonpathogenic viruses do to plants?

In the nature, plants are often persistently infected with viruses without showing disease symptoms, and it is presumed that viruses and host plants are originally in a mutual relationship close to symbiosis. On the other hand, it has been pointed out that the activity of agriculture for food production may have caused a pathogenic virus to emerge. In this seminar, I will mention the true picture of viruses by understanding two aspects of virus as a pathogen and virus as a symbiote in host plants. Infection with viruses having pathogenicity induces disease symptoms in host plants, and host plants have evolved immune system for protect themselves. On the other hand, viruses that persistently infect host plants without showing clear disease symptoms, are not only present in plant tissues, but also play various roles in plant life. I would like to provide a topic about the new roles of viruses in host plant.

Chikara Masuta (Research Faculty of Agriculture, Hokkaido University)

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Survival strategy of Y-satellite RNA of cucumber mosaic virus

Cucumber mosaic virus (CMV) is often associated with a non-coding RNA molecule called satellite RNA (satRNA). When tobacco is infected by CMV containing Y-satRNA, the tobacco leaves turn bright yellow. The yellowing of the leaves does not necessarily reduce photosynthesis. It is induced directly by the Y-sat siRNAs as a result of host RNA silencing, which target the chlorophyll synthase gene mRNA. This yellow tobacco preferentially attracts aphids, which transmit CMV in the fields. In addition, aphids sucking on the yellow tobacco soon turn red and then form wings within a few days. Here, Y-sat dsRNA enters the aphid's body and regulates the expression of the genes involved in wing formation through aphid RNA silencing; Y-sat then spreads using the winged aphids as a private jet.

Special 3 October, 2022 (Mon.) 13:00~14:30

Jinliang Wang (Institute of Zoology, Zoological Society of London, London)

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Fast and accurate population admixture inference from genotype data from a few microsatellites to millions of SNPs

Model-based (likelihood and Bayesian) and non-model-based (PCA and K-means clustering) methods were developed to identify populations and assign individuals to the identified populations using marker genotype data. Model-based methods are favoured because they are based on a probabilistic model of population genetics with biologically meaningful parameters and thus produce results that are easily interpretable and applicable. Furthermore, they often yield more accurate structure inferences than non-model-based methods. However, current model-based methods either are computationally demanding and thus applicable to small problems only or use simplified admixture models that could yield inaccurate results in difficult situations such as unbalanced sampling. In this study I propose new likelihood methods for fast and accurate population admixture inference using genotype data from a few multiallelic microsatellites to millions of diallelic SNPs. The methods conduct first a clustering analysis of coarse-grained population structure by using the mixture model and the simulated annealing algorithm, and then an admixture analysis of fine-grained population structure by using the clustering results as a starting point in an expectation maximization algorithm. Extensive analyses of both simulated and empirical data show that the new methods compare favourably with existing methods in both accuracy and running speed. They can analyse small datasets with just a few multiallelic microsatellites but can also handle in parallel terabytes of data with millions of markers and millions of individuals. In difficult situations such as many and/or lowly differentiated populations, unbalanced or very small samples of individuals, the new methods are substantially more accurate than other methods.

338th 16 September, 2022 (Fri.) 14:00~17:00

Yume Imada (Graduate School of Science and Engineering, Ehime University)

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Exploring function of insect cuticle: a study of moss mimic crane-flies

How are body color, patterns, and structures involved in insect mimicry? Larvae of the Cylindrotominae crane-flies (Diptera: Cylindrotomidae) resemble mosses by their body color, patterns, and the numerous fleshy projections covering their body surfaces. My research group has studied the biology and morphology of larvae and their evolutionary pathways of this group.
Our study has revealed that the arrangement and shape of the fleshy processes of larvae differ among species, and the internal structure and locomotion have suggested that the lateral lobes may function to stabilize the body and assist locomotion. Furthermore, our quantitative analysis of larval body color has revealed that the range of variation in larval body color is various among species, but they can immediately change the body color in accordance with the background color. Such plasticity in body color may be caused by transmitting the background through the translucent cuticle.
Both the outgrowths and transparency of the cuticle in the cylindrotomines presumably contribute to camouflage to the moss by edge diffusion. Finally, I will discuss prospects for the study of the function of the cuticle of insect larvae.

Takao K. Suzuki (Graduate School of Frontier Sciences, The University of Tokyo)

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Genetic basis, phylogenetic evolution, and community ecology of camouflage and mimicry in butterfly wings

Camouflage and mimicry are typical examples of adaptation, and has attracted attention as model traits in ecology and evolutionary biology. Butterflies display a variety of patterns, such as crypsis on dead leaves or rocks, or Mullerian mimicry, have attracted attention since the era of Wallace. I used morphological approaches to study how the patterns are organized and phylogenetic comparative methods to investigate phylogenetic evolution of these patterns.
In this seminar, I will discuss recent advances in butterfly camouflage and mimicry (genetic basis, development and genomics, etc.) and talk about the pattern evolutions from the perspective of macroevolutionary processes.

Special 15 September, 2022 (Thurs.) 13:00~15:00

Angélica Gonzàlez (Department of Biology & Center for Computational and Integrative Biology, Rutgers University / Visiting Associate Professor, Center for Ecological Research, Kyoto University)

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Nutrient Dynamics: Perspectives from microcosm experiments to large-scale surveys and global syntheses

Chemical elements are the building blocks of life and they are found in different proportions in the biomass of living organisms across domains of life. The elemental composition of living organisms or elemental phenotype represents the outcome of selective pressures and biophysical constraints acting on the chemical needs of life to build biomass and perform biological functions. Human activities are modifying major biogeochemical cycles and the trophic state of many habitats worldwide. These alterations are predicted to continue to increase, with the potential for a wide range of impacts on the structure of ecological communities and ecosystem functioning. In this talk, I will discuss how the use of multiple approaches can lead to new insights and better understanding of the patterns and mechanisms of organismal to whole-ecosystem stoichiometry, and their responses to changes in biogeochemical cycles.

Wan-Hsuan Cheng (Taiwan International Graduate Program (TIGP) arth System Science Program, Academia Sinica, Taipei, Taiwan / Visiting Scholar at Ryukoku University)

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New index of functional specificity to predict the redundancy of ecosystem functions in microbial communities

An ecosystem function is suggested to be more sensitive to biodiversity loss (i.e. low functional redundancy) when focusing on specific- type functions than broad-type functions. Thus far, specific-type functions have been loosely defined as functions performed by a small number of species (facilitative species) or functions involved in utilizing complex substrates. However, quantitative examination of functional specificity remains underexplored. We quantified the functional redundancy of 33 ecosystem functions in a freshwater system from 76 prokaryotic community samples over 3 years. For each function, we used a sparse regression model to estimate the number of facilitative Amplicon Sequence Variants (ASVs) and to define taxon-based functional specificity. We also used Bertz structural complexity to determine substrate-based functional specificity. We found that functional redundancy increased with the taxon-based functional specificity, defined as the proportion of facilitative ASVs (= facilitative ASV richness/facilitative ASV richness + repressive ASV (ASVs reducing functioning) richness). When using substrate-based functional specificity, functional redundancy was influenced by Bertz complexity perse and by substrate acquisition mechanisms. Therefore, taxon-based functional specificity is a better predictive index for evaluating functional redundancy than substrate-based functional specificity. These findings provide a framework to quantitatively predict the consequences of diversity losses on ecosystem functioning.

Special 29 July, 2022 (Fri.) 14:00~17:00

Christine L. Weilhoefer (Departments of Biology & Environmental Studies, University of Portland/Visiting Associate Professor, Center for Ecological Research, Kyoto University)

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Nutrient limitation of benthic primary production in rivers: a comparison between Japan and the Pacific Northwest of the US

Human activities can be a major source of nutrients to freshwater ecosystems. However, the delivery and concentration of these nutrients can vary temporally due to both climatic and land use factors. Benthic microalgae (BMA) biomass and community structure in freshwater lotic systems are often limited by inorganic nutrient availability. In the Pacific Northwest of the US, agricultural activities add nutrients to catchments during the dry, summer months, when rivers are uncoupled from their catchments. While in Japan, the agricultural season coincides with the rainy season when rivers and catchments are connected. We examined patterns of nutrient limitation of BMA biomass in two rivers in the Pacific Northwest, US and four rivers in Shiga, Japan along a land use gradient. Our results demonstrate that nutrient limitation correlated to catchment land use, but patterns were not consistent between the US and Japan. In the US, nutrient limitation was highest in watersheds draining pristine catchments, while in Japan, the greatest nutrient limitation was observed in catchments with mixed land use

Luki Subehi (Research Center for Limnology and Water Resources, National Research and Innovation Agency (BRIN) Indonesia)

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Overview and finding unique characteristics of various tropical lakes in Indonesia

Indonesia is listed among the 12 megadiversity countries, ranked as the first in Asia in the number of freshwater fish species. As the settling of water volume, it harbors many species of fish communities. Moreover, there are 5,807 inland waters (lakes and reservoirs) in Indonesia, covering about 586,871.64 Ha of area. Tropical inland water is one of the unique ecosystems which are usually functioning in both ecological and economic services. Recently, there is an increasing need to conserve and maintain the ecological balance of inland water systems which are subjected to massive pressure. Several problems faced are as follows: (1). Lake damage: Level of sedimentation, pollution, eutrophication, highly reduced quality and quantity of water; (2). Lake utilization: Hydropower plant, agriculture, fisheries (aquaculture/floating cage), usable water, religious and culture values, tourism (including lake uniqueness, accessibility, amenity-infrastructure and society condition); (3). Local government's and society's commitment to wisely manage lakes (master plan, local regulation, managing committee); (4). Strategic lake: lakes featuring strategic functions of national interest; (5). Biodiversity (including endemic fish species, aves and vegetation); and (6). Carbon urgency (the challenge against global climate change). Besides Indonesia has a largest caldera lake (Lake Toba, 1,130 Km2 area) in North Sumatera and the deepest tectonic lake (lake Matano, 590 m depth) in South Sulawesi. There Are also more than 100 oxbow lakes in Kalimantan Island and some saline lakes (salinity more than 40 ppt) in the eastern part of Indonesia. The capabilities of the economic values of these inland waters and ecosystem should be balanced. In order to maintain the sustainability of the lakes, basic ecological information is necessary for the next study.

337th 15 July, 2022 (Fri.) 14:00~17:00

Kaori Fujita (Graduate School of Life Sciences, Tohoku University)

(within-CER limited zoom (live) distribution)

International trends in business and biodiversity/natural capital

This summer, the 15th Conference of the Parties (COP15) to the United Nations Convention on Biological Diversity is scheduled to take place and adopt global targets through 2030. Biodiversity and natural capital have become important themes for the business and financial communities. Companies are expected to understand their impact on and dependence on biodiversity in their supply chains, take measures to reduce it, and disclose their efforts. Companies are required to disclose information in accordance with the framework of the Taskforce on Nature-related Financial Disclosures (TNFD), and financial institutions will begin to make use of the disclosed information in their investments and loans. There is an increasing need for companies and for us, consumers who purchase products made by companies, to think about biodiversity conservation.

Keiichiro Kanemoto (Research Institute for Humanity and Nature/Tohoku University)

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Biodiversity losses embedded in global supply chains

Identifying hotspots of species threat has been a successful approach for setting conservation priorities. One important challenge in conservation is that, in many hotspots, export industries continue to drive overexploitation. Conservation measures must consider not just the point of impact, but also the consumer demand that ultimately drives resource use. To understand which species threat hotspots are driven by which consumers, we have developed a new approach to link a set of biodiversity footprint accounts to the hotspots of threatened species on the IUCN Red List of Threatened Species. The result is a map connecting consumption to spatially explicit hotspots driven by production on a global scale. Locating biodiversity threat hotspots driven by consumption of goods and services can help to connect conservationists, consumers,companies and governments in order to better target conservation actions.

336th 24 June, 2022 (Fri.) 14:00~17:00

Yasuhiko T. Yamaguchi (Lake Biwa Environmental Research Institute)

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Reconsidering the size-reactivity continuum model of aquatic dissolved organic matter

Morimaru Kida (Graduate School of Agricultural Science, Kobe University)

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Drivers of molecular composition of dissolved organic matter in Antarctic lakes

A drop of natural water contains hundreds of dissolved organic constituents, collectively referred to as dissolved organic matter (DOM). Although the constituents of DOM are extremely dilute (< nM order), collectively they represent one of the largest active carbon pools on Earth. The turnover of DOM is largely dependent on its molecular composition, and factors that determine the molecular composition have been studied. However, due to extreme heterogeneity of the molecular composition and the multitudes of sources and reactions in the environment, the unambiguous interpretation of observed patterns is challenging. One way to reduce confounding factors is to take advantage of simplified environmental settings where such confounding factors are limited.
In this presentation, I will discuss environmental factors that determine the molecular composition of "microbial" DOM in Antarctic lakes with low anthropogenic impact and limited catchment soil-derived organic matter inputs. I will also discuss how molecular diversity of DOM could evolve in lakes in one of the simplest environments on Earth.

335th 20 May, 2022 (Fri.) 14:00~17:00

Yuko Miyazaki (Faculty of Environmental and Life Science, Okayama University)

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Environmental floral gender determination and its adaptive significance of flowers in andromonoecious Commelina communis f. ciliata

The sex expression of plants is highly diverse, and more than 90% of seed plants have a phenotype of gender in which individual plants have a combination of perfect, pistillate, and staminate flowers within an individual, and the gender of each flower is determined by some environmental factor or developmental process. In animals, the mechanism of environmental sex determination and its adaptive significance have been studied. On the other hand, although environmental sex determination in plants has been reported for a long time, it has not been clarified how multiple environmental factors such as temperature, day length, and resource availability affect sex determination. In this presentation, I would like to introduce our study on the mechanism by which internal resource conditions and day length induce perfect flower and its adaptive significance, using the andromonoecious annual herb Commelina communis f. ciliata, which is one of the phenotypes during the evolutionary process of plants from hermaphroditism to dioecy.

Qingmin Han (Department of Plant Ecology, Forestry and Forest Products Research Institute)

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Mechanisms of mast seeding and associated resource dynamics in temperate forest trees

Mast seeding or masting refers to the synchronous intermittent production of large seed crops in a population of perennial plants. Although its evolutionary significances have been well demonstrated from temperate to tropical forests, its physiological mechanism remains poorly understood. Using long-term field investigation and stable isotopic technology, we demonstrated that nitrogen is the key resource that limits masting in Fagus crenata, whereas stored starch plays a role as a "pinch-hitter" when asynchrony of carbon supply and demand occurs. In addition, the role of carbon resource in other Fagaceae species will be introduced.

334th 22 April, 2022 (Fri.) 14:00~17:00

Takaya Iwasaki (Natural Science Division, Faculty of Core Research, Ochanomizu University)

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Phylogeographic study and adaptive evolution of a widely distributed temperate plant in the Eurasian continent, Cardamine impatiens

The temperate zone in Eurasia extends continuously east to west. Many closely related plant groups such as Fagaceae distribute within this range. However, it is still not fully understood how they spread east to west across the broad continent and differentiated among regions. We focused on a widely distributed temperate plant, Cardamine impatiens (Brassicaceae), as a model for investigating this evolutionary history. This plant has the advantage that we can utilize the molecular genetic information of the closely related Brassicaceae species Arabidopsis thaliana. It has also been suggested that local adaptations exist in various region, such as seacoast populations. In this seminar, I will mainly introduce a phylogeographic study of this species based on genome-wide SNPs, and discuss prospects and challenges.

Kohtaro Shutoh (The Hokkaido University Museum, Hokkaido University)

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Findings and tasks obtained by studies on mycoheterotrophic evolution in pyroloids (Ericaceae)

There are still a lot of mysteries in evolution of fully mycoheterotrophic plants because their extreme morphology or ecology complicate comparisons with closely related chlorophyllous plants. Pyrola japonica species complex (Pyroleae, Ericaceae) would be one of the ideal models for investigating the evolutionary processes. The complex enables to compare various evolutionary traits between closely related plants showing different mycoheterotrophic levels because it includes partial mycoheterotrophic species having developed leaves, nearly fully mycoheterotrophic species having rudimentary scale-like leaves, and intermediates between them. In the seminar, I will introduce phylogenetic, taxonomic, and evolutionary studies on the complex as well as tasks obtained by them.

333rd 18 February, 2022 (Fri.) 14:00~17:00

Shin-ichiro Matsuzaki (Biodiversity Division, National Institute for Environmental Studies (NIES))

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High-frequency observations and international collaborations open new door in lake ecological research

Shang SHEN (Research Center for Environmental Quality Management, Kyoto University / Current: Lake Biwa Branch Office, National Institute for Environmental Studies)

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Roles of viruses in aquatic ecology

332nd 21 January, 2022 (Fri.) 14:00~17:00

Nobutoshi Yamaguchi (Nara Institute of Science and Technology)

(zoom (live) distribution)

Epigenetic regulation of heat memory in Arabidopsis thaliana

Acclimation to high temperature increases plants' tolerance of subsequent lethal high temperatures. Although epigenetic regulation of plant gene expression is well studied, how plants maintain a memory of environmental changes over time remains unclear. In this seminar, I will mainly show my research about four JUMONJI (JMJ) demethylases involved in histone H3 lysine 27 trimethylation (H3K27me3) in response to recurring heat. These JMJ proteins are necessary for Arabidopsis thaliana heat acclimation. Acclimation induces sustained H3K27me3 demethylation at HEAT SHOCK PROTEIN22 (HSP22) and HSP17.6C loci by JMJs, poising the HSP genes for subsequent activation. Upon sensing heat after a 3-day interval, JMJs directly reactivate these HSP genes. Furthermore, jmj mutants fail to maintain heat memory under fluctuating field temperature conditions. Our findings of an epigenetic memory mechanism involving histone demethylases may have implications for environmental adaptation of field plants. In addition to this, I will share my recent progress about a lot of additional regulators for heat response.

Haruki Nishio (The Center for Data Science Education and Research, Shiga University)

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Adaptive evolution of plants approached by seasonal transcriptome

Plants show similar morphologies in seasonal adaptation. For example, many plants flower in warm seasons like spring or summer, bear autumn leaves and overwinter as rosettes. These similarities among species may be able to be observed at gene expression levels. The speaker named this as the transcriptome seasonal hourglass model and is working to verify this hypothesis. The speaker is also studying the molecular background of seasonal adaptation of plants by applying statistical modeling and machine learning to transcriptome and epigenome data. The talk will put special focus on state space model and Bayesian statistics.

331st 17 December, 2021 (Fri.) 14:00~17:00

Takuya Sato (Center for Ecological Research, Kyoto University)

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Ecological community and parasite's infection dynamics: the effects of intermediate and definitive host species richness on the trophic transmission of a hairworm parasite

While recent studies have tested if host diversity can dampen or amplify disease risks, most of those studies have examined parasites with simple life cycle. Many parasites actually have complex life cycle and depend for transmission on intermediate and definitive hosts, which let us speculate the diversity effects of hosts on infection dynamics should be regulated by diverse hosts at different life stages. In this talk, I will provide an empirical example examining how phenological diversities of intermediate and definitive hosts can regulate seasonal transmission dynamics in a horsehair worm, a parasite that has important roles in forested streams. Furthermore, I would like to discuss about the approach integrating empirical and theoretical researches to better understand parasite infection dynamics and disease risks.

Gaku Takimoto (Graduate School of Agricultural and Life Sciences, The University of Tokyo)

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Biodiversity and infectious diseases: effects of vector species richness on the risk of vector-borne infectious diseases

Control of infectious diseases is important for the welfare and health of people and for the management of livestock, crops and wildlife. Recent studies have shown that the diversity of host organisms can dilute or amplify the risk of infectious diseases. However, few studies have examined effects of vector organism diversity on the risk of infectious disease in vector-borne infections, where specific organisms mediate infection between hosts. In this talk, I will present a theoretical study that has investigated the relationship between vector diversity and the risk of vector-borne infectious diseases. In addition, for the control of an infectious disease, it is important to understand an infectious disease network consisting of the pathogen, hosts and vectors. I would also like to discuss empirical approaches to quantify the effects of vector and host biodiversity in infectious disease networks.

330th 26 November, 2021 (Fri.) 14:00~17:00

Akihiro Sumida (Graduate School of Life and Environmental Sciences, Kyoto Prefectural University)

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How does intraspecific competition in a tree population bring about changes to each individual?

One of the big differences between herbaceous plants and trees is that the aboveground part of the latter lives for many years. In herbaceous plants, intraspecific competition results within a year, but how does it occur in a tree population? Many long-term studies have been carried out to answer this question, but such studies often recorded only stem diameter at breast height (DBH) (or occasionally with tree height) for each tree each year. In this seminar I will introduce the results of two papers which could not have been obtained with records of only DBH and tree height; using a record of very detailed measurements taken over 20 years for a hinoki cypress (Chamaecyparis obtusa) population, we analyzed how intraspecific competition accompanied changes to each individual tree, and how environmental factors affected the long-term process of intraspecific competition. In addition, I may discuss what our studies could remind us, i.e., relations between our ecological study and other research fields.

Shigeta Mori (Department of Agriculture, Yamagata University)

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Ontogenetic shift of root/shoot allocation in Fagus crenata

The allocation of metabolic production in terrestrial plants is a zero-sum dynamic. Using 337 Fagus crenata individuals from five different Japanese provenances, we measured whole-individual root and shoot (above-ground) respiration rates, surface area, and fresh mass from seedlings to mature trees. We found that the relatively stable allometry of whole-plant respiration resulted from integrating a convex upward curve of the root and a convex downward curve of shoot to whole-plant fresh mass on the log-log coordinates. This suggests a gradual ontogenetic shift in allocation priority, from water uptake in seedlings to carbon gain in mature trees. We propose that size-related root and shoot shift is common in Fugas crenata, regardless of the environment or phylogeny.

329th 15 October, 2021 (Fri.) 14:00~17:00

Richard Karban (University of California, Davis / Visiting Professor, Center for Ecological Research, Kyoto University)

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Individual Variation in Communication Among Plants

Induced resistance allows plants to increase their defenses when risk of herbivory is great. Plants perceive volatile cues from damaged neighbors to induce resistance. We have studied communication and induced resistance in sagebrush (Artemisia tridentata) in California. Induced resistance in response to volatile cues released by experimentally damaged neighbors reduces herbivore damage. Choice experiments with beetles indicated that beetles avoided induced leaves, leading to damage that was more evenly distributed among leaves on plants.
Recently, we have become interested in variation among individual plants in communication. Different individuals in a population emit different volatile profiles and these groups of volatiles are called chemotypes. Chemotypes may be analogous to languages. Individuals were found to communicate most effectively with other individuals of the same chemotype. Individuals were also found to communicate most effectively with kin compared to unrelated strangers.
We have borrowed from the more developed field of animal communication to guide our studies. When risk of predation is high, animal alarm calls tend to converge to one or a few calls that all individuals can understand. When risk of predation is low, animal alarm calls tend to be more diverse so that individuals use private channels to communicate with kin. We have found a similar pattern with sagebrush populations that have experienced high rates of herbivore pressure had fewer chemotypes and populations that have experienced low rates of herbivore pressure exhibited more diverse chemotypes.
Recent studies in animal behavior have found that individuals of many species exhibit consistent ersonalities, tendencies that are consistent across different situations and over time. We conducted an experiment in which we transferred volatiles from different emitters to different receivers and found that some individuals were consistently more effective communicators than other individuals. The identity of the receiver explained 65% of the variation in herbivory while the identity of the emitter explained 5%, still a statistically significant fraction. Individuals that were good receivers were also good emitters. Pairs of individuals that were effective communicators in one year were also effective communicators in the following year.
In conclusion, individual variation should not be considered as just experimental oise because plant individuals vary consistently in behavioral traits that are ecologically important.

Akira Yamao (Faculty of Agriculture and Life Science, Hirosaki University)

(zoom (live) distribution)

Plant-plant communication based on kin-recognition

328th 17 September, 2021 (Fri.) 14:00~17:00

Masato Yamamichi (School of Biological Sciences, The University of Queensland)

(zoom (live) distribution)

Eco-evolutionary feedbacks of species coexistence

Organisms are rapidly adapting to changing environments and such rapid adaptive evolution can affect various ecological dynamics. However, modern coexistence theory tends to assume that competing species do not have intraspecific genetic variation and their traits do not change over time. Here, I show how rapid evolution can affect competitive exclusion and stable coexistence by using theoretical models. First, I show the effects of intraspecific adaptation load on coexistence. Density-dependent selection for selfish genotypes in intraspecific (social and sexual) interactions decreases population growth rates of species with high population densities (intraspecific adaptation load), strengthening negative frequency-dependence in the community level and promoting coexistence. Second, I explain the relationship between rapid evolution and fluctuation-dependent coexistence. When a competitively superior species destabilizes population dynamics whereas a competitively inferior species stabilizes dynamics due to rapid evolution with a trade-off between growth and mortality, relative nonlinearity (Armstrong-McGehee mechanism) promotes stable coexistence via temporal fluctuations. Finally, I will discuss future perspectives by briefly describing an ongoing project for understanding eco-evolutionary feedbacks of competition through the lens of niche difference and competitive ability ratio and quantifying the relative importance of various coexistence mechanisms as well as phenotypic plasticity and rapid evolution.

Taichi Suzuki (Department of Microbiome Science, Max Planck Institute for Developmental Biology)

(zoom (live) distribution)

Codiversification of gut microbiota with humans and the role of microbes in mammalian ecology and evolution

Animals harbor microbial communities (microbiome) that play an important role in normal development and health and provide opportunities for host-microbial coevolution. However, studying the shared evolutionary history and selection pressures involved between hosts and microbes remains a challenge, especially in mammalian hosts with a complex gut microbiota. Here, I show that multiple species of adult and child gut microbes codiversified within and between human populations. Analyses of paired human genotypes and bacterial strain genotypes from fecal metagenomes, obtained from five countries, indicate that strains of common gut bacteria have transmitted vertically for thousands of generations. In accord, strains are also shared between mothers and children. Patterns of strain transfer between populations are consistent with an African origin for common gut bacteria in humans. A second line of my work uses wild house mice as a model system and explored how the microbiome imposes selection pressure to the host and how the microbiome contributes to host adaptation to new environments by combing both field- and lab-based approaches. I will briefly describe an ongoing experimental evolution project on the wild mouse microbiome and how a selection on the microbiome alone is sufficient to shift host traits within five generations without host evolution. Together, I will discuss how the microbiome can affect host ecology and evolution with and without coevolution.

327th 16 July, 2021 (Fri.) 14:00~17:00

Naoe Hosoda (National Institute for Materials Science)

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Reversible adhesion technology learning from living things

Insects such as flies and ladybird beetles can walk vertically or upside down on flat surfaces such as glass without slipping off. The legs of insects have bristles with excellent adhesiveness, which allow them to repeatedly adhere and peel while walking. In this presentation, I will explain the structure of the sole of the leg of beetles, the principle of adhesion, the limit of adhesion by beetles, the offense and defense of plants and insects, and adhesion biomimetics.

Hirokazu Tsukaya (Graduate School of Science, The University of Tokyo)

(zoom (live) distribution)

Evo-devo studies on leaf morphogenesis: Peculiar types of leaves observed in SE Asian tropics

Currently, evo-devo studies on tropical plants became achievable, and I would like to introduce two of such projects. The first topic is about the genus Monophyllaea, which grows in SE Asian tropics and has only one leaf at the adult stage. The Monophyllaea single leaf is the winner of a competition between initially identical two cotyledons. Although Monophyllaea does not have a shoot apex, inflorescences can still develop on the surface of their cotyledon. How did such unique body plan evolve? The second topic is about the Bornean ant plant Calliarpa saccata, which develops pouches at the base of leaf lamina used as nests by symbiotic ants. Again, how did such curious structures form? In this seminar, our present understanding on the above two topics will be presented, along with information on their natural habitats, which are beautiful places to visit.

326th 25 June, 2021 (Fri.) 14:00~17:00

Kentaro Yoshida (Graduate School of Agriculture, Kyoto University)

(zoom (live) distribution)

Microevolution and allopolyploidization of Triticum and Aegilops species

Triticum and Aegilops species have trait diversity within species. Their allopolyploids can be obtained by interspecific crossing. By linking the genetic and trait diversity of wild species, we are exploring the genetic mechanisms that drive the microevolution and allopolyploidy of these species. We studied genetic polymorphism in the three wild diploid species, revealing genetically divergent lineages, which were associated with their trait differentiations. This result suggests that acquittance of the lineage-specific traits resulted from adaptation to their habitats. When artificially synthesized polyploids were created, the traits of the synthetic polyploids tended to resemble those of the parents with a larger number of chromosomes. This result indicates gene dosage effects in the artificial allopolyploids.

Gen-ichiro Arimura (Faculty of Advanced Engineering, Tokyo University of Science)

(zoom (live) distribution)

Molecular bases of plant-insect interactions

Plants are known to possess solid immune response mechanisms. One such response is "sensing" attack by herbivorous animals. I will present "elicitors"-the molecules that initiate plant defense mechanisms against herbivore attack. I highlight the major types of elicitors and the underlying cellular signaling, and states that this could spur research on organic farming practices.

325th 21 May, 2021 (Fri.) 14:00~17:00

Toyoho Ishimura (Graduate School of Human and Environmental Studies, Kyoto University)

(zoom (live) distribution)

Development of the ultra-microscale stable isotopic analytical technique of CaCO3

In this seminar, I will introduce the analytical system that can analyze the stable carbon and oxygen isotopes δ13C, δ18O) of CaCO3 as low as 0.2 g in high precision, which is less than 1/100 of the amount required by conventional analytical methods. A series of development of this instrument (MICAL) have been carried out at the personal level. I will talk about the background of development, development process, and the applied research in the field of earth sciences and fisheries science.

Ryunosuke Tateno (Field Science Education and Research Center, Kyoto University)

(zoom (live) distribution)

Changes in nitrogen cycling in forest ecosystems along various environmental gradients

For a better understanding of N cycling of forest ecosystems, important to clarify how plant-microbe-soil interactions change in response to various types of environmental gradients. In response to low soil N availability, plants supply low-quality litters to the soil decomposer system and allocate more photosynthate to fine roots and mycorrhizas for efficient N uptake. In recent years, with the development of next-generation sequencing techniques, our knowledge of soil microbes has rapidly increased, and the environmental responses of soil microbes concerning N transformation processes such as N mineralization and nitrification have been clarified. Furthermore, it has been pointed out that differences in mycorrhizal types such as ectomycorrhiza and arbuscular mycorrhiza cause differences in carbon accumulation and N cycling in soils. In this seminar, I will introduce some process studies on forest N cycling that we have conducted in various forests.

324th 16 April, 2021 (Fri.) 14:00~17:00

Alberto Canarini (Center for Ecological Research, Kyoto University)

(within-CER limited face-to-face with zoom (live) distribution)

Soil microorganisms and climate change: current knowledge and prospects

The soil microbiome governs biogeochemical cycling of carbon and nutrients vital for the growth of plants and animal life. Understanding and predicting impacts of climate change on soil microorganisms and the ecosystem functions they govern, present a major challenge as we direct our research efforts towards one of the most pressing problems facing our planet in the Anthropocene. During this talk I will summarize the current knowledge and give insights into recent experimental manipulations of different climate change aspects. I will also focus on present knowledge gaps and on recent promising experimental approaches opening new avenues on the study of climate change effects on soil microorganisms.

Takanori Nishino (Center for Ecological Research, Kyoto University)

(within-CER limited face-to-face with zoom (live) distribution)

Novel microbial symbiotic system in the saw-toothed stinkbug

323rd 26 February, 2021 (Fri.) 14:00~17:00

Motoaki Tojo (Graduate School of Life and Environmental Sciences, Osaka Prefecture University)

(zoom (live) distribution)

Taxonomy and ecology of Pythium

Pythium sensu lato, the major taxonomic group of Oomycete, will be introduced on their taxonomy and ecology. The presentation mainly due to original data and photos from the speaker. Pythium sensu lato comprises around 200 species belonging to the genus Pythium sensu strict, Globisporangium, Phytopythium, etc. The majority are soil inhabitants, but at least a few species can be found in almost every type of habitat where plants can grow. Several species can be significant pathogens on crops and sea weeds. Since ecological characteristics vary greatly among the species, suitable control strategies should be chosen for each pathogen.

Shigeyuki Betsuyaku (Department of Plant Life Sciences, Faculty of Agriculture, Ryukoku University)

(zoom (live) distribution)

Spatiotemporal consideration of plant-microbe interactions

A number of genetic and biochemical studies using model organisms have revealed multiple key molecular components regulating plant-microbe interactions. Integrating spatial and temporal information on the activities of these regulatory components into our genetics-based knowledge will be a next important step towards a better understanding of plant-microbe interactions. In this view, we developed a system enabling us to monitor plant immunity and bacterial virulence in living Arabidopsis leaves infected by Pseudomonas syringae pv. tomato. Our intravital imaging analysis revealed that salicylic acid- and jasmonic acid-signaling pathways, both of which are important for plant immunity but antagonistic to each other, are activated in spatially different domains around the infection sites. Such spatiotemporal dynamics of plant-microbe interactions will be discussed.

322nd 15 January, 2021 (Fri.) 14:00~17:00

Yusuke Onoda (Graduate School of Agriculture, Kyoto University)

(zoom (live) distribution)

Leaf trait diversity of woody species in relation to temperature

To understand plant phenotypic diversity and their ecological significances has been a major subject of plant ecology. Thanks to flourish of "trait ecology", we can now compare many plant traits for thousands of species, which help us to understand various ecological issues including how plants diversify across climate. In this talk, I will discuss how to understand such global patterns of plant traits in relation to a few plant principles.

Mie N. Honjo (Center for Ecological Research, Kyoto University)

(zoom (live) distribution)

RNA-seq reveals plant-virus interaction during persistent infection under seasonal environment

Recently, it has been reported that plant viruses spread widely in plant populations without causing critical damage to their hosts in natural ecosystems. We found that a lineage-to-lineage infection of the host plant Arabidopsis halleri with Turnip mosaic virus continued at least for 3 years. We further revealed that host responses in gene expressions against viral infection using RNA-seq. I will also discuss the advantages of RNA-seq in the applications to ecological research.

321st 18 December, 2020 (Fri.) 14:00~17:00

Ken'ichi Ozaka (School of Environmental Science, The University of Shiga Prefectute)

(within-CER limited zoom distribution)

The hydrological and biogeochemical controls on nitrogen export from watersheds in rainfall and snowfall-melt event

Fujio Hyodo (Research Core for Interdisciplinary Sciences, Okayama University)

(within-CER limited zoom distribution)

Characterization of feeding habits of invertebrates by the isotopic compositions

320th 20 November, 2020 (Fri.) 14:00~17:00

Kazufumi Hosoda (Institute for Transdisciplinary Graduate Degree Programs, Osaka University)

(zoom (live) distribution)

10,000-over synthetic ecosystems toward understanding life and ecosystems

Humankind and Escherichia coli are very different, but it also can be said they are almost the same. Likewise, the ecosystems in Amazon and termite gut are very different, but they still have something essential in common. Escherichia coli, as a "model organism," is still bringing new understandings of life through a huge number of experiments all over the world. Likewise, if we have a model experimental ecosystem that is as easy as Escherichia coli experiments, a huge number of experiments must bring lots of fun discoveries. Here, we constructed a synthetic ecosystem of 12 microbial species with diverse interactions as an experimental "model ecosystem." As all species are cryopreservable, the experiments can be reproduced all over the world, and also evolutionary changes can be analyzed. We developed a machine learning model that noninvasively distinguished all species on micrographs, which enables high-throughput measurements. Our system is still Ver.0, but we have already observed stochastic behavior, keystone species, evolution, oscillation, inter-ecosystems competition, and temperature-response prediction. In the future, the system will be improved so that everyone can test various situations and observe dynamics from molecules to ecosystems. When the time comes, how will we understand ecosystems and life?

Kazuhiro Takemoto (Department of Bioscience and Bioinformatics, Kyushu Institute of Technology)

(zoom (live) distribution)

Inferring microbial community structure: co-occurrence network approaches and metabolic network analysis

Many microbes compose ecological communities via interspecific interactions (e.g., mutualism and competition). Investigating such community networks is important in medical and environmental sciences. In this context, co-occurrence networks are widely used. However, the validity of these methods simply has been evaluated using parametric statistical models, even though microbial compositions are determined through population dynamics. We therefore comprehensively evaluated the validity of common methods for inferring microbial ecological networks through more realistic simulation using the generalized Lotka olterra equations. Contrary to previous studies, the prediction performance of the state-of-art methods was almost equal to or less than those of earlier methods. Prediction performance also depended upon interaction types. Our findings indicated the limitations of co-occurrence network approaches in microbiome studies. Thus, we also considered an alternative approach: reverse ecology. Inspired by the importance of metabolic crosstalk between microbes, I am developing software for estimating microbial community structure using metabolic network analysis: Estimator of COmmunity Structure based on MetabOlic networkS (ECOSMOS). ECOSMOS uses a snapshot of a microbial population to infer cooperative interactions (i.e., complementary support of nutrients) and competitive interactions (i.e., scramble for nutrients) based on the nutrient metabolites identified from metabolic networks through network analysis. Moreover, ECOSMOS evaluates the stability and reactivity of ecological communities based on the strength of interactions and species abundances according to the random matrix theory. As a case study, we investigated how the structure and function of microbial communities differed between diabetic patients and healthy people. We will present a few of our finding.

[1] H. Hirano and K. Takemoto, BMC Bioinform 20, 329 (2019).

319th 16 October, 2020 (Fri.) 14:00~17:00

Takehito Yoshida (Research Institute for Humanity and Nature & Graduate School of Arts and Sciences, The University of Tokyo)

(zoom (live) distribution)

Research and Social Implementation of Ecosystem-based Disaster Risk Reduction as Climate Change Adaptation in Shrinking Societies

Yukihiro Shimatani (Graduate School of Engineering, Kyushu University)

(zoom (live) distribution)

Hope for the recovery of our land by basinwide comprehensive flood disaster management

318th 18 September, 2020 (Fri.) 14:00~17:00

Takeshi Osawa (Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University)

(within-CER limited zoom distribution)

Strategic management for alien invasive plants -case for Ogasawara islands-

Ogasawara islands is one of highest biodiversity area in Japan. In Ogasawara islands there are investing much efforts for management of the alien invasive species. In any cases on management of alien invasive species, effective and low-cost management strategies are needed. In this talk I would like to introduce the basic idea on what is management strategy first, then, I reviewed current status for management on 3 alien invasive plants these are Bischofia javanica, Leucaena leucocephala and Casuarina equisetifolia in Ogasawara islands. Finally I would like to introduce some studies which aim to contribute management strategy on Leucaena leucocephala in Ogasawara islands.

Kenji Hata (College of Commerce, Nihon University)

(within-CER limited zoom distribution)

Loss of ecosystem functions caused by severe disturbances of feral goats in oceanic islands can limit restoration

For restoration and management of ecosystems disturbed by invasive mammals, they have been eradicated in many islands. Ecosystem recovery after the eradication would depend on processes of loss of ecosystem functions before and after their eradication. I introduce several studies about processes of changes in ecosystem functions before and after eradication of feral goats in Nakodo-jima, a subtropical archipelago in the northwestern Pacific. I focused on relationships between vegetation states and soil chemical properties with vegetation degradation, soil erosion. In addition, I propose a new framework of more flexible and practical restoration of island ecosystem disturbed by invasive mammals using a concept "novel ecosystem", which should be one of goals of disturbed ecosystems in islands.

317th 17 July, 2020 (Fri.) 14:00~17:00

Kohmei Kadowaki (Field Science Education and Research Center, Kyoto University)

(online web distribution)

Plant-soil feedback and the dynamics of temperate forest communities

Plant-soil feedback is defined as an interaction among plants, soil organisms, and abiotic soil conditions, and recent studies suggest that plant-soil feedback is considered as a significant factor regulating plant species diversity and community structure. I have investigated how soil fungi mediate plant-soil feedback and affect the structure and dynamics of tree communities through field manipulation experiments. In the seminar I show some recent findings about the effects of plant soil feedback revealed by comprehensive analysis of various seedling growth parameters, soil chemical composition, soil microbial communities and above-ground herbivorous insects and predator communities. I focus primarily on the effects of plant-soil feedback on seedling growth inequality and the role of terrestrial herbivorous and predatory insects, both of which have often been neglected in previous studies.

Yasuo YAMAUCHI (Graduate School of Agricultural Science, Kobe University)

(within-CER limited zoom distribution)

How plants use volatiles as communication tools?

Green leaf volatiles (GLVs) are rapidly emitted volatiles when leaves are wounded. (E)-2-Hexenal is a representative member of GLVs emitted when not only wounded but oxidative and heat stress conditions. (E)-2-Hexenal induces oxidative and heat stress-responsive genes, thus (E)-2-Hexenal acts as an infochemical involved in the stresses. Rapid production of (E)-2-Hexenal is supported by a series of enzymes, and plants can recognize 2-hal by plausible receptor resemble those of mammals and insects. Therefore, plants can communicate with others via (E)-2-Hexenal to inform the coming emergency. In this seminar, I introduce a concept that plants use volatile infochemicals as "Phyto-language" as communication tools.

316th 19 June, 2020 (Fri.) 14:00~17:00

Michitaka Notaguchi (Nagoya University)

(within-CER limited zoom distribution)

Study on Nicotiana grafting revealed a common mechanism among grafting, wound healing and parasitism

Ken Naito (NARO)

(within-CER limited zoom distribution)

I am mesmerized -Diversity and utility of salt tolerance evolution in the genus Vigna

315th 15 May, 2020 (Fri.) 14:00~17:00

Shin-ichi Nakano (Center for Ecological Research, Kyoto University)

(within-CER limited zoom distribution)

A unique microbial loop in the hypolimnion of Lake Biwa

Noboru Okuda (Center for Ecological Research, Kyoto University)

(within-CER limited zoom distribution)

Ecology in Transdisciplinary Science: A case study of watershed governance

315th 17 April, 2020 (Fri.) 14:00~17:00 Canceled

This Seminar has been canceled due to the severe situation where coronavirus (COVID-19) is still expanding. The abstract of the scheduled lecture will be posted as it is.

Matteo Convertino (Faculty of Information Science and Technology, Hokkaido University)

Critical Interactions: Disentangling Environment-Biota Complexity across Life Scales in Basin Ecosystems

A unified theoretical and computational multiplex metacommunity model is presented to infer, predict and design complex ecosystems at different biological and spatio-temporal scales. The fundamental role of the environment (specifically hydrogemorphological networks) and critical interactions is highlighted in shaping functional species networks, extreme events, and phase transitions associated to healthy and dysbiotic ecosystems states. The model is proposed for ecosystems of increasing complexity form rivers, wetlands, to ocean systems in which species populations and communities are analyzed. Patterns of collective organization and early-warning indicators are proposed to assess the optimality of ecosystems and their divergence. The quest is for a general metabolic theory of basin ecosystem function (such as information processing machines) which leads to understanding complex environmental dynamics underpinning biota organization, bio-inspired monitoring technology design, and multiscale ecosystem engineering for desired ecosystem services. Examples of ongoing microbiome engineering projects connecting science and technology are provided for aquatic and terrestrial ecosystems as well as ecohydrological design where ecological function is explicitly taken into account.

Kohmei Kadowaki (Field Science Education and Research Center, Kyoto University)

Plant-soil feedback and the dynamics of temperate forest communities

Plant-soil feedback is defined as an interaction among plants, soil organisms, and abiotic soil conditions, and recent studies suggest that plant-soil feedback is considered as a significant factor regulating plant species diversity and community structure. I have investigated how soil fungi mediate plant-soil feedback and affect the structure and dynamics of tree communities through field manipulation experiments. In the seminar I show some recent findings about the effects of plant soil feedback revealed by comprehensive analysis of various seedling growth parameters, soil chemical composition, soil microbial communities and above-ground herbivorous insects and predator communities. I focus primarily on the effects of plant-soil feedback on seedling growth inequality and the role of terrestrial herbivorous and predatory insects, both of which have often been neglected in previous studies.

Special 28 February, 2020 (Fri.) 14:00~15:30

Ji Zhou (Head of Data Sciences, Cambridge Crop Science, UK; Professor of Crop Phenomics, Nanjing Agricultural University, China)

Multi-scale crop phenomics for breeding resource use efficiency cereal crops between the UK and China

With the development of cross-disciplinary research, plant phenotyping and phenotypic analysis have become a popular research domain in recent years, an area catalysed by a range of technologies such as computer vision, remote sensing, machine learning and deep learning. Phenotyping is aiming to collect evidence of plant during its entire life cycle and at different scales. Using indoor and outdoor phenotyping platforms in the UK and China, we are studying a variety of key performance-related phenotypes for both wheat and rice. We analysed different levels of phenotypes for cereal crops, from cells, tissues, organs and plants, to plots and fields, in a high-throughput and reproducible manner. Phenotypic analysis results are then utilised for gene discovery, crop breeding, cultivation, and agricultural production. In the seminar, the speaker is going to talk about these platforms and how they are applied in studying resource use efficiency for wheat and genetic variation for rice. A number of new deep learning and computer vision approaches will also be introduced, which unravel how to extract complex traits that enabled us to link traits to key genes in multi-year field experiments.

314th 21 February, 2020 (Fri.) 14:00~17:00

Yuuya Tachiki (Department of Biological Sciences, Tokyo Metropolitan University)

Mathematical Modeling for the interpretation of ecological phenomena

Mathematical Models (e.g., dynamical systems) have been used for the interpretation of the ecological phenomena. In this talk, I would like to talk how to utilize mathematical models in the context of the feedback between empirical and theoretical approaches. I would like to propose two approaches from the various ways to utilize mathematical models. The first one is the qualitative prediction by a mathematical model and the validation by experiments. The strength of simple models is the interpretability. Understanding how the model works helps to construct how we can confirm its logic by experiments. The second one is an approach for estimating parameters included in a mathematical model. We are basically interested in phenomena within a range of biologically plausible region in the parameter space. Estimating parameters by experiments should help restricting ourselves within a biologically meaningful range. I, this time, try to explain how to utilize these approaches by giving specific examples of researches of mine.

Mayumi Seto (Faculty of Science, Nara Women's University)

Bioenergetic challenges of understanding the microbial interactions and metabolic evolution

Hydrothermal vents are one of the many likely incubators for the first life on Earth. The recent findings of the metabolic feature of the last universal common ancestor, short for LUCA, that harnesses H2 and CO2, also supports the idea of hydrothermal vents as the location for life's origin. Whereas animals are purely dependent upon aerobic respiration reaction as their energy source, microorganisms can harness a variety of reactions. In general, the energy-harvesting reactions of microbes inhabiting the deep subsurface generate significantly lower energy in comparison with aerobic respiration. Our recent researches based on the bioenergetic population model showed that the survival of microbes in such environments might significantly rely on the mutualistic interactions. I here introduce the basics of bioenergetics, the examples of mutualistic energetic interactions among microbes, and our recent findings on the microbial survival strategies under energetic constraints and how microbes enable them to invade a new environment.

313th 17 January, 2020 (Fri.) 14:00~17:00

Fumitoshi Ishino (Medical Research Institute, Tokyo Medical and Dental University)

Mammalian-specific genomic functions: genomic imprinting and retrotransposon-derived acquired genes

Mammals have evolved a unique viviparous reproductive system and a highly developed central nervous system. How did these unique characteristics emerge in mammalian evolution, and what kinds of changes did occur in the mammalian genomes as evolution proceeded? A key conceptual term in approaching these issues is "mammalian-specific genomic functions", a concept covering both mammalian-specific epigenetics and genetics, such as genomic imprinting and LTR retrotransposon-derived acquired genes, respectively. I will show how they play essential roles in the current mammalian developmental system and discuss how the genomic imprinting mechanism and the acquired genes emerged in the course of mammalian evolution.

Tetsuji Kakutani (Graduate School of Science,The University of Tokyo)

Evolution of sequence-specific anti-silencing systems in Arabidopsis

The arms race between parasitic sequences and hosts is a major driving force for evolution of gene control systems. Since transposable elements (TEs) are potentially deleterious, eukaryotes silence them by epigenetic mechanisms such as DNA methylation. Little is known about how TEs counteract the silencing to propagate during evolution. Here we report behavior of sequence-specific anti-silencing proteins used by Arabidopsis TEs and coevolution of those proteins and their target sequences. Through this coevolution, these TEs propagate with minimum host damage. Our findings provide insight into the evolutionary dynamics of these apparently "selfish" sequences.

312th 20 December, 2019 (Fri.) 14:00~17:00

Naoko Tokuchi (Field Science Education and Research Center)

Social system for Connectivity of hills, humans and oceans

The Field Science Education and Research Center engages in educational and research activities aimed at reinforcing the Connectivity of hills, humans and oceans. In this presentation, I would like to introduce the social cooperation component of the project supported by the Nippon Foundation. The purpose of this project is to clarify the linkage between forests and oceans, and to show the influence of land environmental factors over oceans' biological components and diversity. Even though the research has advanced on these topics, the results must still return back to the society and knowledge sharing is needed. For that reason, we have explored the arrangement of mechanisms/ ways to share the achieved knowledge and to promote the cooperation/coordination between forests and oceans related stakeholders. In this presentation, I would like to explain our effort to reinforce the cooperation between varied stakeholders.

Kazuo Isobe (Graduate School of Agricultural and Life Sciences, The University of Tokyo)

Role of soil microbes in nitrogen cycling and their response to environmental change

Soil microbial communities play critical roles in ecosystem functioning such as carbon transformation, nutrient cycling and plant host defense. The composition of these communities can change over space and time and is sensitive to a variety of global changes, and such shifts can alter their functioning. However, the enormous diversity of soil microbes creates a challenge for a predict understanding of microbial community shift. In this seminar, I will introduce the studies focusing on how seasonal and spatial shift in composition and functions of a soil microbial community can contribute to nitrogen cycling and plant growth in a forest. I will also introduce a phylogenetic approach for predicting how soil microbial communities respond to a variety of global changes.

311th 15 November, 2019 (Fri.) 14:00~17:00

Ko Yasumoto (School of Marine Biosciences, Kitasato University)

Polyamines A biogenic substance for CO2 capture

Polyamines are generally considered low-molecular-weight compounds that have multiple amino groups, are present at high concentrations in the cells of all organisms and are essential for both cell differentiation and proliferation. We recently reported that polyamines can capture CO2 and accelerate bicarbonate/carbonate formation in aqueous solutions. Polyamines may function in the formation of dissolved inorganic carbon reservoir in organisms, which regulates biogenic calcification and photosynthesis. This novel mechanism of CO2 fixation by polyamines adds a new pathway to the global carbon cycle and further suggests a new concept for CO2 removal that could reduce atmospheric CO2 levels and, therefore, global warming.

Keiko Yamaji (Graduate School of Life and Environmental Sciences, University of Tsukuba)

Root-endophytic fungi could enhance metal-tolerance in plants naturally growing at mine sites

Plants naturally growing in mine sites ecologically and physiologically adapt to high concentrations of metals and acidity in the soils. Recently, many researchers have paid attention to root-endophytes, which enhance stress-tolerance in plants. In this presentation, metal-tolerances of Clethra barbinervis and Miscanthus sinensis growing in mine sites will be explained, considering functional root-endophytes. For example, root-endophytes enhanced heavy-metal tolerance in C. barbinervis via the increase of the growth and the decrease of heavy-metal concentrations. Root-endophytes also enhanced aluminum tolerance in M. sinensis via production of siderophore, which can detoxify metals. Therefore, these plants would survive in mine sites, via interactions with root-endophytes symbiotically. Additionally, in this presentation, other research examples showing interactions between plants and root-endophytes will be explained.

Special 24 October, 2019 (Thurs.) 14:00~17:00

Luisa Isaura Falcon Alvarez (Universidad Nacional Autonoma de Mexico)

Bacalar lagoon microbialite reefs

Microbialites are highly diverse bacterial communities that represent modern similes of the oldest life forms, stromatolites (dated >3.5 Ga). Bacalar lagoon, in Mexico, harbors the largest freshwater microbialite occurrences of the world, yet diverse anthropogenic activities are changing the oligotrophic conditions of the lagoon. In this seminar, we will review current research aimed at the exploration of the microbialites in Bacalar lagoon, in order to analyze their microbial genetic diversity and correlate the environmental parameters that structure these communities following a 16S rDNA sequencing approach. Results suggest that there are two main microbialite bioregions associated to gradients in conductivity, bicarbonates, ammonium and NOX. The difference between these microbialite bioregions was further associated with a strong anthropogenic pressure on water quality (agriculture, landfill leachate, lack of water treatment infrastructure and intensive tourism).

Christine L. Weilhoefer (Visiting Associate Professor, Center for Ecological Research, Kyoto University / University of Portland)

The use of microalgae as a bioassessment tool in large-scale aquatic surveys within the United States

Bioassessment is the evaluation of the health of an ecosystem based on the community of organisms that live within it. The bioassessment approach is used by scientists and resource managers around the world to quantitatively measure the ecological health of aquatic ecosystems and to monitor the impacts of stressors on these ecosystems. This seminar will focus on the utility of microalgae in the bioassessment of aquatic ecosystems. Microalgae are ideal organisms for aquatic bioassessment due to their short lifespans, rapid reproduction rate, and sensitivity to a variety of environmental conditions, particularly nutrients. Data from several microalgae-based bioassessments conducted throughout the United States on lakes, streams, wetlands, and coastal areas will be presented.

Special 21 October, 2019 (Mon.) 14:00~17:00

Horst Malchow (Institute of Environmental Systems Research School of Mathematics / Computer Science, Osnabruck University Barbarastr. 12, 49076 Osnabruck, Germany

Functional response of competing residents and invaders to environmental variability

The possible control of competitive invasion by infection of the invader and multiplicative noise is studied. The basic model is the Lotka-Volterra competition system with emergent carrying capacities. Several stationary solutions of the non-infected and infected system are identified as well as parameter ranges of bistability. The latter are used for the numerical study of diffusive invasion phenomena. The Fickian diffusivities, the infection but in particular the white and colored multiplicative noise are the control parameters. It is shown that not only competition, possible infection and mobilities are important drivers of the invasive dynamics but also the noise and especially its color and the functional response of populations to the emergence of noise. The variability of the environment can additionally be modelled by applying Fokker-Planck instead of Fickian diffusion. An interesting feature of Fokker-Planck diffusion is that for spatially varying diffusion coeffcients the stationary solution is not a homogeneous distribution. Instead, the densities accumulate in regions of low diffusivity and tend to lower levels for areas of high diffusivity. Thus, the stationary distribution of the Fokker-Planck diffusion can be interpreted as a refection of different levels of habitat quality [1-5]. The latter recalls the seminal papers on environmental density, cf. [6-7]. Appropriate examples will be presented. References [1] Bengfort, M., Malchow, H., Hilker, F.M. (2016). The Fokker-Planck law of diffusion and pattern formation in heterogeneous media. Journal of Mathematical Biology 73(3), 683-704. [2] Siekmann, I., Malchow, H. (2016). Fighting enemies and noise: Competition of residents and invaders in a stochastically uctuating environment. Mathematical Modelling of Natural Phenomena 11(5), 120-140. [3] Siekmann, I., Bengfort, M., Malchow, H. (2017). Coexistence of competitors mediated by nonlinear noise. European Physical Journal Special Topics 226(9), 2157-2170. [4] Kohnke, M.C., Malchow, H. (2017). Impact of parameter variability and environmental noise on the Klausmeier model of vegetation pattern formation. Mathematics 5, 69 (19 pages). [5] Bengfort, M., Siekmann, I., Malchow, H. (2018). Invasive competition with Fokker-Planck diffusion and noise. Ecological Complexity 34, 134-13. [6] Morisita, M. (1971). Measuring of habitat value by the \environmental density" method. In: Spatial patterns and statistical distributions (Patil, C.D., Pielou, E.C., Waters, W.E., eds.), Statistical Ecology, vol. 1, pp. 379-401. Pennsylvania State University Press, University Park. [7] N. Shigesada, N., Kawasaki, K., Teramoto, E. (1979). Spatial segregation of interacting species. Journal of Theoretical Biology 79, 83-99.

Merlin C. Kohnke (Institute of Environmental Systems Research School of Mathematics / Computer Science, Osnabruck University Barbarastr. 12, 49076 Osnabruck, Germany)

Spatiotemporal patterns in a predator-prey model with Holling type IV functional response

A simple reaction-diffusion predator-prey model with Holling type IV functional response and logistic growth in the prey is considered. The functional response can be interpreted as a group defense mechanism, i.e., the predation rate decreases with resource density when the prey density is high enough [1]. Such a mechanism has been described in diverse biological interactions [2,3]. For instance, high densities of filamentous algae can decrease filtering rates of filter feeders [4]. The model will be described and linked to plankton dynamics. Nonspatial considerations reveal that the predator may go extinct or coexistence (stationary or oscillatory) between predator and prey may emerge depending on the choice of parameters. However, including space, the dynamics are more complex. In particular, spatiotemporal irregular oscillations can rescue the predator from extinction. These oscillations can be characterized as spatiotemporal chaos. Possible underlying mechanisms for this phenomenon will be discussed. References [1] Freedman, H. I., Wolkowicz, G. S. (1986). Predator-prey systems with group defence: the paradox of enrichment revisited. Bulletin of Mathematical Biology, 48(5-6), 493-508. [2] Tener, J. S.. Muskoxen in Canada: a biological and taxonomic review. Vol. 2. Dept. of Northern Affairs and National Resources, Canadian Wildlife Service, 1965. [3] Holmes, J. C. (1972). Modification of intermediate host behaviour by parasites. Behavioural aspects of parasite transmission. [4] Davidowicz, P., Gliwicz, Z. M., Gulati, R. D. (1988). Can Daphnia prevent a blue-green algal bloom in hypertrophic lakes? A laboratory test. Limnologica. Jena, 19(1), 21-26.

310th 18 October, 2019 (Fri.) 14:00~17:00

Osamu Kishida (Field Science Center for Northern Biosphere, Hokkaido University)

Toxicity appeared: exploring the impacts of an alien toad on native amphibians in Hokkaido

Ryoichi Tabata (The origin and history of endemic fishes in Lake Biwa based on molecular genetics)

The origin and history of endemic fishes in Lake Biwa based on molecular genetics

309th 20 September, 2019 (Fri.) 14:00~17:00

Yusuke Saijo (Graduate School of Science and Technology, Nara Institute of Science and Technology)

How do plants recognize and control pathogens and endophytes?

Plants are in nature colonized by a rich diversity of microbial communities, which provide a key basis for plant adaptation to fluctuating environments. Plant-inhabiting microbes range from pathogens, commensals to mutualists, and even change their infection modes depending on the environmental conditions. Indeed, abiotic factors, such as nutrients, humidity or temperature, profoundly influence mutualistic plant-microbe associations and plant disease epidemics. Plant immunity largely relies on cell-surface immune receptors that recognize microbe- or damage-associated signals and intracellular receptors that recognize pathogen-derived virulence effectors. Following a basic framework of the plant immune system and pathogen recognition principles, I will introduce recent studies on the mechanisms by which plants integrate microbial and environmental cues to modulate immune responses and beneficial associations with microbes.

Tokitaka Oyama (Graduate School of Science, Kyoto University)

The circadian system of plants from a cell's point of view

Most organisms have circadian clocks and adapt themselves in the diurnal environments. The circadian clock is a cell-autonomous system and individual cells work as cellular clocks. Time of the clock can be detected by using bioluminescence reporter systems with circadian rhythms. By observing plants/organs/tissues/cells for bioluminescence rhythms, time of the circadian clock can be detected at various hierarchies of plant. Through studies of those circadian rhythms, qualities/precisions of cellular clocks, coordination of circadian behavior in a plant body, synchronization of the clock to day-night cycles have been revealed. Recent results for the circadian system of plants will be introduced.

Special 2 August, 2019 (Wed.) 15:00~16:30

Ji Zhou (Project leader, Earlham Institute (EI), Norwich Research Park (NRP), UK / Professor of Crop Phenomics, Nanjing Agricultural University, China)

Combining machine learning and computer vision to address challenges in multi-scale plant phenotyping for crop improvement

308th 19 July, 2019 (Fri.) 14:00~17:00

Motohiro Hasegawa (Faculty of Science and Engineering, Doshisha University)

The relationships between soil mesofaunal community structures and forest disturbances

Community of soil mesofauna (Collembola, Oribatida etc.) has been studied with the relationships of their feeding habit and decomposition process of litter. The forest disturbances have caused the changes in the community structures of mesofauna. Manipulation studies have been used to clarify the reason of the changes in community structures of mesofauna. I would like to introduce the studies above and discuss about the future study using trait of soil fauna or stable isotope.

Nobuhiro Kaneko (Faculty of Food and Agricultural Sciences, Fukushima University)

Designing conservation agriculture based on soil ecology

Ecological studies in agriculture mostly focused on conservation of organisms in and around croplands, whereas there are only few studies on diversity and agricultural productivity. While, birds and pollinators are major target organisms, soil biodiversity has been ignored. Conservation agriculture is defined as minimal soil disturbance (no-till, NT) and permanent soil cover (mulch) combined with rotations, as a more sustainable cultivation system, and is recommended by FAO for small-scale family based farmers. This management will ecologically enhance soil biodiversity, thus it enable us to maintain stable production with lower cost by using plant-soil feedback. We studied soil food web structures comparing different agricultural management in field manipulation and farmers practices. Modern agriculture largely violates natural nutrient cycling. In order to establish sustainable food production, we propose a method to promote conservation agriculture by evaluating soil ecosystem functioning.

307th 21 June, 2019 (Fri.) 14:00~17:00

Yosuke Toda (Institute of Transformative Bio-Molecules, Nagoya University)

Plant phenotyping via utilization and understanding of representation learning in image quantification

Keisuke Koba (Center for Ecological Research, Kyoto University)

Stable isotope techniques applicable to the ecological studies: recent progress in the methodologies and the future directions

Special 17 April, 2019 (Wed.) 15:00~

Allen Herre (Smithsonian Tropical Research Institute, Panama)

Coevolutionary Vignettes of (Mostly) Mutualistic Interactions

I will discuss the implications of recent empirical advances in our understanding of the evolution and ecology of species interactions, with special reference to the constellation of organisms associated with figs, and the interactions between host plants and their foliar endophytic and arbuscular mycorrhizal fungi (AMF).

Special 10 June, 2019 (Mon.) 14:00~

Michael Bode (Queensland University of Technology)

Creating empirically-validated models of pelagic larval dispersal

Most coral reef fish spend their larval stage dispersing in the open ocean. The distance they travel has important implications for coral reef ecology and conservation, but our current understanding of where larvae go is limited because our data is sparse, and our simulation models are unvalidated. I will outline new methods for validating oceanographic simulations of larval dispersal using genetic parentage assignment datasets. I will then apply them to a case-study of Plectropomus maculatus dispersal from the southern Great Barrier Reef in Australia. A coupled oceanographic-biological model of larval dispersal was constructed for the system, based on our best understanding of the species' behaviour (adult spawning, larval behaviour and ontogeny). This model was parameterised to match an extensive genetic parentage dataset that collected and analysed a large number of adults and juveniles in the system (> 2,000), and positively identified 69 parent-juvenile relationships, over distances of up to 200 km. I will then describe two different examples of how larval dispersal can have a substantial impact on the conservation and management of reef fish metapopulations.

Hiroyuki Yokomizo (National Institute for Environmental Studies)

A new population statistic for comparative plant demography - Inter-stage flow matrix

Population matrix models enable us to derive population statistics that describe the life history characteristics of species or populations such as life expectancy, elasticity and population growth rate. I developed a new population statistic, inter-stage flow matrix, which explicitly describes the inter-stage flows of individuals derived from projection matrices and stable stage distributions. I compared the inter-stage flows of several functional groups using projection matrices from the Plant Matrix Database, COMPADRE version 4.0.1. Inter-stage flows describe distinct demographic properties compared to elasticity and other population statistics. Elasticity describes how a perturbation will influence future population growth rate. In contrast, inter-stage flow directly describes current contributions to population growth rate (at present). Inter-stage flow matrices have potential to provide unique ecological insights that complement other population statistics.

306th 17 May, 2019 (Fri.) 14:00~17:00

Wataru Iwasaki (Graduate School of Science, the University of Tokyo)

Bioinformatics toward "meta"-ecosystem analysis

Daichi Morimoto (Graduate School of Agriculture, Kyoto University)

The interactions between toxic bloom-forming cyanobacteria and its viruses

Special 17 April, 2019 (Wed.) 15:00~

Allen Herre (Smithsonian Tropical Research Institute, Panama)

Coevolutionary Vignettes of (Mostly) Mutualistic Interactions

I will discuss the implications of recent empirical advances in our understanding of the evolution and ecology of species interactions, with special reference to the constellation of organisms associated with figs, and the interactions between host plants and their foliar endophytic and arbuscular mycorrhizal fungi (AMF).

305th 19 April, 2019 (Fri.) 14:00~17:00

Maiko Kagami (Graduate School of Environment and Information Sciences, Yokohama National University)

Fungi in aquatic ecosystems: Diversity, spatial-temporal dynamics and ecosystem functioning

Aquatic ecosystems remain frequently overlooked as fungal habitats, although fungi potentially hold important roles for organic matter cycling and food web dynamics. Molecular analyses of environmental DNA samples have revealed an unexpectedly large diversity of undescribed fungi, so called "dark matter fungi" (DMF). Combining molecular techniques with isolation and microscopic observations are powerful tools, by which we indeed discovered that most of DMF belongs to the novel linages of early diverging branches of the fungal tree of life, i.e. Chytridiomycota. Many of them have zoospores, which can swim in water and utilize various organic matters, including phytoplankton in lakes and oceans. In this talk, I will talk about diversity and spatial-temporal dynamics of aquatic fungi, biological interactions and functioning in biogeochemical cycling.

Takeshi Miki (Faculty of Science and Technology, Ryukoku University)

Feedback between bacterial community assembly and carbon accumulation in aquatic ecosystems

Microbial communities in the ocean are responsible for carbon processes. Microbial carbon pump, proposed by Nianzi Jiao and his colleagues, hypothesizes that bacteria community and trophic interactions within microbial food web are the producer of refractory dissolved organic matter (RDOM) and thus responsible for its accumulation. The likely mechanism is that bacteria physiologically produce RDOM (e.g. compounds to realize stable cell membrane) for maximizing individual survival. In this study, we investigated another mechanism from ecological point of view, especially based on the concepts of community assembly and feedback between community and environment. Through mathematical modeling of bacteria community-carbon cycle feedback and metaanalysis of published data from the ocean, we demonstrated the potential impact of the feedback on carbon accumulation in the ocean.

304th 15 February, 2019 (Fri.) 14:00~17:00

Takaaki Itai (Graduate School of Science, The University of Tokyo)

(I) Geochemical cycle of manganese and arsenic in Lake Biwa

(II) Application of mercury stable isotope ratio for the ecological research

(I) Biogeochemical cycle of Mn and As in bottom of Lake Biwa is of interest because (i) these elements clearly enriches in the surface sediment due to active redox cycle and (ii) spatial distribution of the enriched-layer has been changed since 1970s. Here I present result of geochemical survey including speciation of Mn and As in cored sediment and porewater to model these dynamics near the lake bottom. (II) Mercury stable isotope can be a unique tool in ecological research because it often gives mass-independent fractionation (MIF) via specific photochemical reaction in atmosphere and aquatic environment. This characteristics enable us to examine the depth of MeHg assimilation by aquatic organisms. Here I show an application study using skipjack tuna from North Western Pacific Ocean.

Yasuhiko T. Yamaguchi (Lake Biwa Environmental Research)

Microbial production and degradation of organic nitrogen in aquatic environments indicated by amino acids and nitrogen isotope analysis

Most organic nitrogen in environments exists as detrital nitrogenous material in dissolved and particulate organic matter (DON and PON), which play key roles in nitrogen cycling across multiple aquatic environments such as the ocean and lakes. We have been exploring the use of compound-specific nitrogen isotope ratio of amino acids or enantiomer ratio of amino acids of DON and PON samples as new approaches to examine relative sources, transformation processes, and the potential coupling of these two major forms of N cycle in the aquatic environments. In this seminar, I discuss the roles of heterotrophic microbes in production and degradation of DON and PON based on our recent results.

303rd 18 January, 2019 (Fri.) 14:00~17:00

Keiichiro Tokita (Graduate School of Informatics, Nagoya University)

Species Abundance Distribution of Ecological Networks

In community ecology, the relation between diversity, stability and species abundance distribution (SAD) has been discussed as one of the "unanswered questions in ecology in the last century" (May, 2000)'. In special, theoretical understanding of SAD for a system in a single trophic level has been greatly progressed in the last decade, based on Hubbell's neutral theory. Meanwhile, for more complex systems occurring on multiple trophic levels and including non-neutral species with various types of interspecies interactions among them, a pioneering work by May, which triggered a controversial debate on the relation between diversity and stability, has demonstrated efficacy of a linear analysis and the theory of random matrices. Beyond the linear model, statistical mechanics have been employed for analyzing nonlinear models and have provided global and quantitative information for diversity, stability and SAD. While we have clarified relationships among the strength of the intraspecific competition, asymmetry of interspecies interactions and SAD for a system with fully-connected interactions (Tokita 2004, 2006; Yoshino, Galla and Tokita, 2008; Tokita 2015), we here present that sparse interactions essentially change SAD and it reveals multiple peaks which have been discovered in several field researches but was not demonstrated theoretically (Obuchi, Kabashima and Tokita, 2016). Sparseness of the interspecies interactions, moreover, gives novel non-monotonic dependence of diversity on the ratio of mutualistic interactions, suggesting that the mutualism is not a positive factor for species coexistence in a system with sparse interactions. Since the present theory is based on the general replicator dynamics, the theoretical prediction can be verified not only in community ecology but also in ecological epidemiology, population genetics, game theory, chemical reaction networks, gene regulatory networks and evolution of grammer, etc., and the significance of sparse and mutualistic interactions may give a broad impact on those areas.

Atsushi Mochizuki (Institute for Frontier Life and Medical Sciences, Kyoto University)

Controlling cell fate specification system based on network structure

Modern biology provides many networks describing regulations between bio-molecules. It is widely believed that dynamics of molecular activities based on such regulatory networks are the origin of biological functions. On the other hand, we have a limited understanding for the dynamics of molecular activity based on such complex networks. To overcome these problems, we developed a new theoretical framework (linkage logic theory) with which key nodes for controlling nonlinear dynamics are identified only from network structures without assuming quantitative details, such as functional form, parameter or initial state. According to this theory, the dynamics of a system is controllable to converge on any solution by controlling a subset of nodes called a feedback vertex set (FVS). Here, we applied this theory to a gene regulatory network for the cell fate specification of seven tissues in the ascidian embryo, and found that dynamics of this network consisting of 92 factors are controllable by controlling only five key molecules. By controlling the activities of these key molecules, the specific gene expression of six out of seven tissues observed in the embryo was reproduced. This work is a collaboration with group of Dr. Yutaka Satou, Kyoto University.

302nd 21 December, 2018 (Fri.) 14:00~17:00

Futoshi Nakamura (Graduate School of Agriculture, Hokkaido University)

Current status of Japanese rivers, focusing on habitat environment, ecosystem linkage, and climate change

Hikaru Nakagawa (Field Science Education and Research Center, Kyoto University)

Changes in a stream ecosystem by deer overabundance

Special 19 November., 2018 (Mon.) 10:30~12:30

Stacey Halpern (Professor, Pacific University/Guest Research Associate, Center for Ecological Research, Kyoto University)

Insect herbivore effects on population dynamics of the clonal weed Solanum carolinense

Understanding what determines population size and how it changes over time is a central question in basic plant ecology. It also has important conservation applications to both threatened and invasive species. This project asks whether insect herbivore effects on individual plant fitness also influence plant population dynamics. Herbivores may affect plant populations by altering the population growth rate (λ), a density-independent measure. They may also affect population regulation by changing patterns of density dependence in the plant population. Assessing herbivore effects on density dependence is required to determine whether herbivores affect the equilibrium population size of a plant, a key assumption of biological control efforts and the enemy release hypothesis. We tested the effects of herbivores on population dynamics over four years using experimental populations of Solanum carolinense in its native range. The experimental populations varied in plant density and herbivory, which affected plant size and reproduction; oviposition by a specialist beetle (Leptinotarsa juncta) also increased on plants growing at lower density. Using data from these populations, we parameterized models, and described population dynamics with and without herbivores. Herbivores affected population growth (λ), though effects varied in magnitude and direction among years. Herbivores also altered density dependence, sometimes increasing it and sometimes decreasing it. Finally, herbivores reduced equilibrium plant population size, with effects again varying among years. These results demonstrate that understanding how herbivores contribute to plant population processes like invasions or control of weedy species requires accounting for density dependence, but that herbivore effects on plant population dynamics vary greatly among years. Herbivore effects may also differ in introduced populations in Japan, where preliminary results show lower damage levels than in the US and the loss of a latitudinal gradient in damage.

301st 9 November, 2018 (Fri.) 14:00~17:00

Asano Ishikawa (National Institute of Genetics)

Molecular and genetic basis underlying freshwater colonization and adaptation in sticklebacks

Colonization of empty niches can trigger rapid speciation and adaptive diversification. One of the remarkable examples is the diversification of threespine sticklebacks. After glacial retreats, marine ancestral sticklebacks have colonized newly formed freshwater habitats, resulting morphological, physiological and behavioral diversification. Not all lineages, however, have seized these ecological opportunities to colonize freshwater environments. Here we focused on two stickleback species, threespine stickleback (Gasterosteus aculeatus) and closely related Japan Sea stickleback (G. nipponicus): the former has colonized novel freshwater habitats and diversified, but the latter could not. What molecular and genetic factors determine the difference in the ability to colonize novel niches? In this talk, we will present a key gene responsible for variation in the physiological ability of freshwater colonization and the subsequent adaptation in sticklebacks.

Koji Takayama (Graduate School of Science, Kyoto University)

Global phylogeography of pantropical plants with sea-drifted seeds

Pantropical plants with sea-drifted seeds have an extraordinarily wide range of distribution in littoral areas of the tropics and subtropics worldwide. The global distribution of such plants could be attributed to interactions between geographical barriers and long-distance seed dispersal via ocean currents, which are manifest in species distribution, genetic structuring, and evolutionary history. In this study, I conducted global phylogeographic analyses in two genera, Hibiscus (Malvaceae) and Rhizophora (Rhizophoraceae), to discuss, 1) biogeographic history of species, 2) evolutionary consequences of extreme long-distance seed dispersal, and 3) ecological niches shift of coastal plants.

300th 19 October, 2018 (Fri.) 14:00~17:00

Akira Umehara (Environmental Research Management Center, Hiroshima University)

Dynamics of cyanotoxin in ecosystems

Eutrophication of freshwaters and brackish waters has led to an increase in the occurrence of harmful cyanobacterial blooms in various geographically different areas of the world. Toxic cyanobacteria produce the potent hepatotoxins, microcystins (MCs), which are highly toxic to the livers of mammals, and often promote liver tumors. In this presentation, I'd like to focus on the widespread dispersal and accumulation of MCs in ecosystems of the Isahaya reservoir and its surrounding sea area.

Kanako Ishikawa (Lake Biwa Environmental Research Institute)

Submerged macrophyte management in the South Basin of Lake Biwa

An ecological regime shift from a turbid water state to a clear water state has occurred since 1994 in the South Basin of Lake Biwa. Excessive submerged macrophytes cause oxygen depletion in the bottom layer and cyanobacterial blooms (Aoko) in coastal areas. They can also block pumps and sluices, impede navigation, and cause a decline in the fishery industry and recreational activities. Controlling their proliferation is a major challenge for lake management. We have studied effective removal methods, including the timing of cutting and removal, macrophyte effects on associated organisms, development of a benchmark indicating when management intervention is required and prediction of seasonal growth using a logistic model. Recently, a new problem of filamentous algae has been appearing in areas where the macrophytes have been removed. In this seminar, I discuss the difficulty of managing excessive aquatic plant growth based on our past studies.

299th 21 September., 2018 (Fri.) 14:00~17:00

Yuki Baba (Institute for Agro-Environmental Sciences, NARO)

Effects of environmentally friendly farming on biodiversity and biological control potential in rice paddy ecosystems

Taizo Nakamori (Graduate School of Environment and Information Sciences,Yokohama National University)

Role of sporocarp traits in the interaction between fungi and fungivorous microarthropods

298th 20 July., 2018 (Fri.) 14:00~19:00

Yuma Takahashi (Graduate School of Science, Chiba University)

(1) Linking evolution and ecological functions of genetic diversity

(2) Information design principles for scientific presentation

297th 15 June., 2018 (Fri.) 14:00~17:00

Tomoyuki Saitoh (Tohoku Research Center, Forestry and Forest Products Research Institute)

Gregarious flowering habit and regeneration process of tropical bamboos under the influence of forest fire

Knowledge about life history and reproductive characteristics are recently accumulated in Japan. Little is known about tropical bamboos. We investigated the demography data of culm for the four bamboo species coexist in mixed deciduous forest in Thailand on the period from flowering stage to early regeneration process, and have identified the genet from a clump structure. We have investigated the mortality factors in the reduction curve of genet of bamboo to start the regeneration all at once. Gregarious flowering event of GA and CP was detected by demography data in 1998 and 2001, respectively. GA flowered almost of all genets in 8 of the nine plots. A huge number of genets participated in the flowering event, and died after that. Then, survived genets were observed in all plots. There is a possibility that flowering genets were reproductive or no flowering genets were extant. When the parent genet of them were died, lack of bamboo canopy was occurred, because the next generation start from seed germination. Genet of BT with a large culm began to increase immediately while flowering event have occurred. BT in 6 of nine sub-quadrats was to become the primary dominant species. For the forest fire occurred in 2010, genets with culm >1m high would not be affected by the fire. However, genets with culm only <1m high are affected by the fire.

Takuya Okabe (Graduate School of Integrated Science and Technology, Shizuoka University)

What drives the evolution of phyllotaxis?

Leaf-like appendages of different plant groups are arranged in common patterns categorized into two types: whorled and spiral arrangement, phyllotaxis. The evolutionary cause of this morphological convergence is unknown. While whorled arrangement shows a persistent pattern of alternating whorls of leaves, spiral arrangement entails occasional changes among a sequence of patterns in the course of growth. In the latter, the sequential patterns of mature leaves originate from non-overlapping patterns of nascent leaves characterized with a unique divergence angle 137.5 (degrees). Here I put forward a new view that phyllotaxis is an internal adaptation to a structural constraint rather than an adaptation to environment. Both types of arrangement are caused by a common tendency of leaves to overlap on each other, which is in direct opposition to an intuitive view that leaves avoid overlap to maximize light capture.

296th 18 May., 2018 (Fri.) 14:00~17:00

Shinji Yabuta (Faculty of Life and Environmental Sciences, Teikyo University of Science)

Evolution of motivational conflicting behaviors

When conflicting between two motivations of inconsistent actions, such as an attack and flight, animals often perform a third-party action: displacement actions, ambivalent actions, and/or the autonomic responses. What advantage is there to performing these conflicting behaviors? We are considering that these behaviors have been evolving for better decision-making. In this seminar, I am going to introduce some motivational conflicting behaviors in animals in fighting and then talk about our models to explain the evolution of these behaviors.

Kayoko O. Kameda (Lake Biwa Museum)

Is the Great Cormorant a pest or benefactor?: ecological function and ecosystem services and disservices of the Great Cormorant

The Great Cormorant has ecosystem function of nutrient transportation from aquatic to terrestrial areas by foraging fish in freshwater areas and build a nests on the tree in a forest. Although this function provides supporting and provisioning services by contributing global nutrient cycles and supplying a good organic fertilizer, the Great Comorant also has conflicts with people such as competition over Ayu, the most important fish for present inland fisheries in Japan, and deforestation caused by the breeding activities and the excreta. In order to decrease the conflicts between cormorants and people and enjoy ecosystem services, it is important to clarify the factors causing ecosystem services and disservices and balance between them. In the seminar, I would like to introduce various relationships between cormorants, forests, and people and discuss the factors related to ecosystem services and disservices by the cormorants.

Special 24 April., 2018 (Tues.) 15:00~

Marc T. J. Johnson (Distinguished Visiting Associate Professor, Center for Ecological Research, Kyoto University / University of Toronto, Mississauga)

Evolution in the urban Jungle

Urban areas represent the fastest growing ecosystem on earth, in which the development of cities dramatically changes the biotic and abiotic environment to create novel ecosystems. Despite the importance of urbanization, we have little understanding of how urbanization affects the evolution of species that live in cities. In this talk, I will review our current knowledge of about the effects of cities on multiple evolutionary processes, including mutation, gene flow, genetic drift and natural selection. I will then describe our work examining how these evolutionary processes affect the ability of plants to adapt to urban environments. I will conclude with a discussion of existing gaps in our knowledge and a description of the first global study of urban evolution, in which we are looking for Japanese collaborators.

295th 20 April., 2018 (Fri.) 14:00~17:00

Hitoshi Nakayashiki (Graduate School of Agricultural Science, Kobe University)

Are viruses alive?

"What is life?" is a fundamental question in biology. However, this question is more frequently asked in popular science rather than in academic research. In this seminar, I will ask "What is life?" focusing on viruses. Viruses are generally regarded as a pathogen but they can also be mutualistic with the host. Recent research has revealed that viruses are very diverse in terms of genome size, encoded genes, population, and ecology. Especially, I focus on giant viruses that carry genomic DNA larger than some bacterial genomes, and mutualistic viruses that could have contributed to the evolution of the host.

Kohei Koyama (Obihiro University of Agriculture and Veterinary Medicine)

A lognormal distribution of the lengths of terminal twigs on branches of elm trees

It is well known that the "additive" effect of errors generated the normal (Gaussian) distribution and the "multiplicative" effect of errors generated the lognormal distribution. The sequential breakage model has established a link between sequential processes and lognormal distributions and has been used to explain species abundance distributions. We applied this idea to a tree branch that was generated by a sequential branching process. We tested the hypotheses that the distribution of the lengths of terminal stems of Japanese elm trees (Ulmus davidiana var. japonica), the end products of a sequential branching process, approaches a lognormal distribution. Our results were generally in agreement with the hypothesis. (Koyama et al. 2017 Proc Roy Soc B 284:20162395)

294th 16 February., 2018 (Fri.) 15:00~17:00

Takahiro Irie (Atmosphere and Ocean Research Institute, the University of Tokyo)

Intraspecific variation and larval dispersion of marine benthos

Marine benthos shows a broad life-history variation in the early ontogenetic stage, ranging from the direct development lacking dispersal ability to the indirect development species with a long-time planktonic stage. Their ecological study is still quite preliminary and leaves many unsolved questions, because they are too minute to trace in the field, distribution area is vast, and the total number of individuals is uncountable. Nevertheless, continuing technological progress and low-pricing of DNA-sequencing and parallel computing hardware provide us a good opportunity to address the challenging problems. I will talk about the ongoing project on the planktonic larvae of intertidal cowries and present a future perspective.

293rd 19 January., 2018 (Fri.) 14:00~17:00

Shingo Iwami (Department of Biology, Kyushu University)

New era of ECOEPI in Japan

Since 2016.4.1, we are trying to establish a new feild "Ecological Epidemiology", called ECOEPI(, by internationally collaborating with several groups as a vitual network institute. Especially, we are inerested in infectious diseases among human, animal and insect. In this CER seminar, I would like to talk about our activity from the percspective of both pure science and social implementation sience. Specifically, I am going talk about our modeling and prediction study on malaria spread in South Africa, collaboraing with NEKKEN, Nagasaki University. Then, I would like to introduce our developing web application, called "Virtual ECOSYSTEM", in order to tell how ecology and population dynamics, which are basis of our technical approaches, are interesting for non-academic peoples including junior high and high school students. If I have much time, I will talk about our activity to implement Virtual ECOSYSTEM in our society as well.

Tomoki Nakaya (Department of Geography, Ritsumeikan University)

Spatial epidemiology with perspectives on the past, present and future of infectious disease outbreaks in Japan

Spatial epidemiology is a newly emerged field to spatially describe and analyse epidemiological phenomena, particularly about geographical variations in health risks and their association with environmental factors. Spatial analysis has occasionally played a special role to reveal hidden knowledge for controlling diseases in observed epidemiological data, particularly through effective geo-visualization of health risks. In recent days, spatial epidemiology has been substantially advanced by the advent of the geographical information system (GIS), development of various geo-spatial information, and the enhancement of spatial statistics functionalities. Considering another talk focusing on infectious disease ecology in this seminar, I will introduce the approaches of spatial epidemiology with selected topics on the past, present and future of infectious disease outbreaks in Japan. The topics may include historical disease map study on Typhoid fever in early 20th century, modelling of recent infectious disease outbreaks (syphilis or influenza), and estimating future risk distribution of a mosquito-borne disease (Dengue fever) in Japan. With these, I intend to argue on the possibilities and challenges in spatial models, geo-visualization methods, and newly available geographic information, as well as possible applicability of these to the research field of ecology which has developed spatial analysis likewise if time allows.

292nd 15 December., 2017 (Fri.) 14:00~17:00

Kaoru Kitajima (Graduate School of Agriculture, Kyoto University)

Tolerance of the ultimate shade in the understory of tropical moist forests

Shade tolerance is one of the most central concept in ecology of vegetation succession and dynamics of forest communities. Yet, conflicting views exist on the mechanisms that underpin shade tolerance, i.e., what ecophysiological traits explain species differences in shade tolerance. In today's presentation, I will share my research insights from tropical moist forest in Panama, including the long-term monitoring of growth and survival of a seedling cohort of Tachigali versicolor (Fabaceae) for 29 years, a field experiment in which seedlings of several species transplanted in the understory (0.8% of the full sun) received a treatment of additional 90% shade, and comparative analysis of over 60 tree species to link the species differences in seedling survival and their functional traits. A perspective emerging from these studies is that seedling survival in the deep shade of forest understory, where light availability is just about the light compensation point, hinges upon NOT on traits that allow maximization of photosynthetic income and growth rates, but traits that enhance tissue toughness to defend against a broad array of natural enemies, as well as resource storage that enables rapid recover from unfortunate setback caused by accidents and natural enemy attacks.

Makoto Kobayashi (Field Science Center for Northern Biosphere, Hokkaido University)

EEffect of unique disturbance and climate change in cold biome on northern vegetation

Although tundra and boreal forests have important ecosystems function such as huge carbon storage, it is known to be vulnerable for warming climate. To predict the future of structure and function of these vegetation, we still need to enhance our basic understanding how these vegetation in cold biome is maintained. Our group has been investigating the mechanisms through which the soil frost and fire dynamically influence the structure of tundra and boreal forest respectively, with special focus on soil change. It has been demonstrated that time after the severe soil frost creates the gradient of species diversity in tundra vegetation. Furthermore, the growth of regenerating plants in post-fire forest is revealed to be supported by the fire-produced charcoal. In the end, we would like to introduce some latest achievements about the influence of ongoing advancing snowmelt on northern plants, which is being evaluated with large-scale field manipulation in our experimental forest.

291st 17 November., 2017 (Fri.) 14:00~17:00

Masakazu Shimada (Graduate School of Arts and Sciences, University of Tokyo)

Coexistence or extinction?: projection matrix analysis and adaptive evolution in two Anisopteromalus parasitic wasps

Comparing the two closely related parasitic wasps, Anisopteromalus quinarius and A. calandrae, is very interesting to analyze elasticity of the Leslie matrix with phenotypic plasticity. A. calandrae did not show any plasticity of life history parameters because they suck host larvae with straw they made using the ovipositor. On the other hand, A. quinarius showed great phenotypic plasticity of life history parameters, depending on feeding (honey) or not. We analyzed the Leslie matrix and analyzed elasticity of the two species. Competition replacement experiments showed that density-dependent growth rate of A. quinarius could never compete better than A. calandrae. Therefore, coexistence of A. quinarius with A. calandrae in Europa and Northern America widely is suggested due to the niche separations on the primary host insects and their habitats.

Shigeto Dobata (Graduate School of Agriculture, Kyoto University)

Experimental tests of social evolution in insects

In this seminar, I will provide two topics from my recent research: 1) We identified socially parasitic lineage in the parthenogenetic ant Pristomyrmex punctatus. Individuals of the lineage, called "cheaters," reproduce more than workers but never participate in cooperative tasks for their colonies. We experimentally confirmed that the fitness interaction of cheaters and workers meets the conditions of the public goods dilemma. 2) To test how kin selection affects the evolution of competitive traits, an experimental evolution using the adzuki been weevil Callobruchus chinensis is running. Preliminary results support the view that an altruistic trait indeed evolves in the high-relatedness treatment.

290th 20 October., 2017 (Fri.) 14:00~17:00

Yuko Sasaki-Sekimoto (School of Life Science and Technology, Tokyo Institute of Technology)

Evolution and diversity of land plant extracellular lipid

Adaptation of plants to land environments is a crucial point for current prosperity of life on this planet. To understand such land adaptation processes, we focused on a terrestrial alga Klebsormidium nitens (Division Charophyta, Order Klebsormidiales), and reported the draft genome sequence (Hori et. al., Nat commun 2014). Our comparative genome analysis revealed that K. nitens has a set of genes to synthesize cuticular waxes. We chemically analyzed wax components of K. nitens, and found that triacylglycerols (TAGs) and alkanes were the major components. We also investigated aliphatic substances in the cell wall fraction of K. nitens. Many of fatty acids were determined to be lipophilic monomers in K. nitens. Therefore, we propose that K. nitens has a cuticle-like hydrophobic layer composed of lipids and glycoproteins, with a different composition from the cutin polymer typically found in land plant cuticles (Kondo et al., Front Plant Sci. 2016). I compared the composition of cuticular waxes extracted from land plants as well as K. nitens. K. nitens had TAGs on cell walls, and land plants have highly diversified cuticular waxes. I will discuss about the roles of cuticular during land adaptation process of plants.

Kazuyuki Tanaka (Takii & Co., Ltd.)

Traditional vegetable breeding in seed company and application of new breeding technology

Vegetable breeding was started by selecting local landrace which performed better in that region. Hybrid variety were developed to improve its performance based on human demand and economical reason. If we change our viewpoint, we can say that vegetables are the result of evolution by such artificial selection. Now we can apply many new breeding technologies and genome information which lead to accelerate this egoistic procedure. Now it will be possible to create a new vegetable crop ever exist. I will present some examples to show what we achieved by traditional breeding and what happened now in this segment.

289th 15 September., 2017 (Fri.) 14:00~17:00

Richard Karban (Visiting Professor, Center for Ecological Research, Kyoto University / Department of Entomology and Nematology, UC Davis)

What can plant biologists learn about communication from animals?

Animal communication and behavior are far better understood than similar processes in plants. Plants lack central nervous systems but nonetheless face similar selection pressure to sense their environments and to respond appropriately. Human behaviorists differentiate between judgment and decision making. This distinction may also be useful for plants. Plants that do not respond appropriately may err in judgment or decision making.

Animals and plants differ in other important ways. Plants tend to be less mobile; instead of fleeing, they redistribute defenses or valuable resources. Plants tend to be made up of redundant, modular organs; this allows them to be better able at accomplishing multiple tasks simultaneously. Plants can generally tolerate attack and loss of tissues better than animals; this makes induced defenses a more profitable strategy for plants than for animals.

Junji Takabayashi (Center for Ecological Research, Kyoto University)

A novel enzyme secreted from spinnerets of feeding silkworms hampers green leaf volatile production in mulberry leaves

In response to herbivory, plants emit volatile organic compounds, such as green leaf volatiles (GLVs) and volatiles terpenoids that attract carnivorous natural enemies of herbivores. The attraction was called induced indirect defense of plants against herbivores. Since the attraction of natural enemies is maladaptive to currently infesting herbivores, it is likely that herbivores have evolved to suppress the production of such volatiles to make themselves more inconspicuous to natural enemies. However, this possibility has not yet been tested. Here, we clarified this in a tritrophic system of mulberry plants, silkworms and parasitoid flies, Zenillia dorosa. Silkworms suppressed the GLV production in mulberry leaves by using a novel enzyme in the spinneret secretion, and its function was only for this suppression. The suppression made silkworms less conspicuous to the parasitoid flies. This study showed that herbivorous insects could manipulate induced-indirect defense in plants.

Stable Isotope Ecology seminar (open) 27 July., 2017 (Thur.) 14:00~15:30

Erik Hobbie (University of New Hampshire,

Isotopic Explorations of Fungal Functioning in Ecosystems

Fungi are ubiquitous in terrestrial ecosystems, with many either being key decomposers (saprotrophs) or forming symbioses with many of the dominant plants of temperate, boreal, and tundra ecosystems (ectomycorrhizal fungi). In this latter function, fungi receive carbon as sugars and in return supply nutrients to their host plants, with fungi differing greatly in their exploration strategies and enzymatic capabilities. Here, we explore fungal functioning using stable isotope (C and N) and radiocarbon measurements, including: (1) saprotrophic lawn fungi as integrators of competition between C3 and C4 grasses in lawns, (2) wood decay fungi partitioning resources among species based on the age of the wood being assimilated; (3) fungivorous small mammals preserving a signal of organic nitrogen uptake by fungi in their hair, and (4) linking exploration type in ectomycorrhizal fungi to enzymatic capabilities, carbon demand, and where fungi are active in the soil profile.

288th 21 July., 2017 (Fri.) 14:00~17:00

Ryutaro Goto (Seto Marine Biological Laboratory, Field Science Education and Research Center, Kyoto University)

Evolution and adaptation in commensal clams

Symbiotic associations between animals are common and abundant in the sea and play an important role in generation and maintenance of marine biodiversity. The Galeommatidae is a group of small clams that exhibits tremendous diversity in the intertidal zone and is the most species-rich family among the Bivalvia. Interestingly, many members of this family are commensals associated in highly specific relationships with benthic invertebrates, such as crustaceans, annelids and echinoderms, that burrow in soft sediments. I will talk about their evolutionary transitions between commensal and free-living lifestyles, diversification pattern involving host shifts across phyla, and morphological adaptations to each host association.

Taisuke Kanao (Graduate School of Human and Environmental Research, Kyoto University)

Biodiversity and evolution of termitophilous rove beetles

Termite colonies host many other insects that are commonly referred to as termitophiles. A large number of termitophiles have evolved within the beetle family Staphylinidae, especially in lineages of the subfamily Aleocharinae. The termitophilous robe beetles generally have species-specific relationships with their host termites and exhibit unique morphology such as physogastric and limuloid body plans. Most termitophilous rove beetles, together with termites, are distributed in tropical regions, although many countries within these regions remain poorly studied. I performed faunal surveys in several tropical regions to clarify the species diversity of termitophiles and to get materials for further phylogenetic study. I will present the result of taxonomic works and molecular phylogeny of termitophilous species in Aleocharinae as well as the current knowledge on their basic ecology.

287th 16 June., 2017 (Fri.) 14:00~17:00

Kazuya Kobayashi (Field Science Education and Research Center, Kyoto University)

Selfish genes establish complex community

In the Origin of Species, Darwin discussed one of the challenges that workers of eusocial insects presented to his theory of natural selection. The natural selection theory predicted that traits producing more children will spread throughout the population, but in social insects such as ants and bees, very few individuals (queens) in the nest only reproduce, and many other individuals (workers) do not produce offspring by themselves. Why this sterility can be spread in some lineages of Hymenoptera? This challenge was solved by Hamilton in 1964. His breakthrough was to realize that the gene coding sterility can be transmit to the next generation through the reproduction of relatives. Thus, he showed that natural selection does not maximize number of offspring but that of genes. This expanded theory of natural selection, called as kin selection theory, has been supported by diverse aspects of social organisms. One of the strong evidences is female-biased investment by workers in the eusocial Hymenoptera where relatedness to sisters is higher than to brothers due to haplodiploidy. In recent years, there has been an increasing debate over whether the evolution of altruism is better understood using kin selection. Difficulty to test the theory in diplodiploidy is a potential source of doubts about generality of the theory. In the seminar, I introduce our research where we expanded the kin selection theory to explain biased sex allocations of diplodiploidy. Our model predicts that allocation will be biased towards the sex that contributes more of its genes to the next generation only when sex-asymmetric inbreeding occurs. The prediction matches well with the empirical sex allocation of Reticulitermes termites. Our findings indicated that diplodiploidy organisms also maximize number of their genes due to kin selection. I also introduce my recent research focusing on biological community, which showed that, even in this scale that is over species differences, the principal factor creating biological patterns will be the evolutionary force on genes.

Shinya Shoda (Nara National Research Institute for Cultural Properties / BioArCh, University of York)

Organic residue analysis for the reconstructing of cuisine in the coastal area of the Japan Sea during the Holocene sea level rise

Investigating the use of natural resources and foodways of people in the past are important topic in archaeology. In these decades, mostly in UK, organic residue analysis of pottery has been widely applied to understand what kind of food were processed using pottery, that is frequently found through excavations. In Japan, our previous study revealed that in Torihama site in Fukui prefecture, from the Late Pleistocene to mid Holocene (14k to 5k BP), pottery was predominantly used for cooking marine and freshwater resources despite environmental and socio-economic change. Here, to test whether this pattern is applicable for other sites, Torihama was compared with other four sites (8k-6k BP) located coastal area of the Japan Sea. 143 potsherds and 78 adhered organic materials were analyzed by GC-MS and GC-c-IRMS. As a result, frequent existence of aquatic biomarkers, high SRR diastereomer ratio in phytanic acid, as well as relatively high carbon stable isotope ratio of specific fatty acids corresponding to modern/archaeological marine organisms were observed, that are reliably support the intensity of aquatic resource processing in these pottery. This pattern contrasts strongly with that of other Eurasian prehistoric cultures such as in Europe and Middle East, which helps us to understand the diversity of use of natural resource and foodways in global scale.

286th 19 May., 2017 (Fri.) 14:00~17:00

Karel simek (Biology Centre AS CR, Hydrobiological Institute)

Community dynamics of bacteria and bacterivorous flagellates modulates carbon flow to higher trophic levels in freshwater ecosystems

Small protists, largely heterotrophic flagellates, are considered to be the major link connecting dissolved organic material, bacteria and the grazer food chain in aquatic ecosystems. We are now facing a paradox in contemporary microbial ecology: high throughput molecular techniques have provided detailed insights into bacterioplankton community composition, but this is in sharp contrast to our knowledge concerning the ultimate fate of particular bacterial groups. Ignorance of dynamics, both bottom-up and top-down induced, translates into the discovery of high proportions of particular lineages in freshwater bacterioplankton but this may not imply that these bacterial groups grow rapidly or play an important role in carbon flow to higher trophic levels. Selective grazing of flagellates on bacteria has been suggested to modulate bacterioplankton community composition. However, the flagellate predator-bacterial prey relationships are so flexible that changes in the prey community, vice versa, may induce extremely rapid changes in the flagellate predator community as well. We show that the rapid flagellate growth, as detected by their feeding on different bacteria, tightly corresponds to doubling times for rapidly growing bacterioplankton groups. Notably, different bacterioplankton species likely represent different food quality resources for flagellate communities, affecting their growth, community dynamics and carbon flow to higher trophic levels. However, our knowledge of these essential aspects of carbon dynamics in plankton environments is quite limited. In this seminar, I present our research on the flagellate predator-bacterial prey trophic interactions, efficiency of carbon transfer from relevant bacterioplankton groups to the predators, and some novel techniques allowing us to study these trophic interactions at a high taxonomic resolution. We propose a conceptual model explaining the strong linkages between rapid bacterial community shifts and succeeding flagellate predator community shifts, which optimize prey utilization rates and carbon flow from various bacteria to the microbial food chain.

Luisa I. Falcon Alvarez (Visiting Professor, Center for Ecological Research, Kyoto University / Professor, Universidad Nacional Autonoma de Mexico)

Biogeography and phylogeny of Synechococcus: Lake Biwa and Mexican lakes, home of sister groups

Cyanobacteria have evolved to be one of the most diverse and ancient groups of bacteria on Earth. They contribute significantly to global primary production via photosynthesis and some in addition to the nitrogen cycle via nitrogen (N2) fixation. Cyanobacteria are common components of aquatic ecosystems, responsible for ~40% of global CO2 fixation. Genome scale analysis suggests that oxygenic photosynthesis evolved early in the cyanobacterial radiation. The capacity to use water as electron donor in oxygenic photosynthesis, with its consequent generation of free oxygen, most likely appeared by 2,700 million years ago (MYA). Picocyanobacteria are common in lakes and oceans, where Synechococcus are amongst the dominant genera. Synechococcales are a non-monophyletic diverse group comprising both unicellular and filamentous forms, all with parietal thylakoids. Although the ecological relevance of this group is widely acknowledged, questions regarding the phylo-genesis of Synechococcus remain unclear. So far we know that there are endemic Synechococcus, whereas other members of the genus relate to environmental parameters including salinity, and certain species are widely distributed, while others are constrained. Recent advances in the field have suggested that Synechococcus form clades with specificity to oceanic, epilimnetic saline and freshwater ecosystems. Interestingly, Lake Biwa Synechococcus isolates are closely related to strains from Lake Atexcac in central Mexico. Both lakes are freshwater, P-limited environments that sustain large populations and diversity of picocyanobacteria, including Synechococcus. The Biwa/Atexcac cluster is further associated to subalpine lake Synechococcus, as well as to high altitude Patagonian lakes. The vast genetic dispersal of certain Synechococcus strains makes them an excellent model to study both biogeographic patterns in microorganisms and adaptation mechanisms from closely related picocyanobacteria inhabiting a vast geographical and environmental range. I will discuss the proposed approach to work with Synechococcus from different ecogeographic regions as a model to help explain the phylogenetic relationships in the group, as well as ecological parameters related to s diversity. The study models are Synechococcus from Lake Biwa as well as other strains from Mexican lakes. We want to understand the life history behind similar Synechococcus strains retrieved from highly different environments. This study aims to unravel what are the contributing factors that explain co-occurrence of Synechococcus from distant environments and if there are other components of the bacterioplankton assemblage also shared between geographically distant sites.