「Research history and research plan of Song Uhram」

Dr. Dr. Song Uhram (NRFK Postdoc Researcher)

A: Research History

1. Brief introduction of Ph. D Thesis: (Monitoring and management of a landfill)

2. Global climate change related researches: Global climate change can increase invasive plant performance/change regeneration pattern of forest

3. Nano material researches: Agglomeration of nanoparticles is the key factor of its toxicity

4. Wetland research: Phytoremediation researches / NGO activity

5. Others

B: Research plan

1. Effects of irrigation and flooding on P dynamics of Yasu/Soma river and lake Biwa; a Phosphate oxygen isotopes as a tool to trace phosphorus sources and cycling

Phosphate oxygen isotopes of Yasu/Soma river (upstream) and downstream will be researched. Since a lot of irrigation and fertilization is expected during the golden week, we will be able to tell anthropogenic P input to rivers and to the lake Biwa. By using similar method, we will investigate what is the main P source and what is their fate to aquatic ecosystems during the flooding season.

2. Assessing ecosystem functions of lagoons by biodiversity and environmental factors using phosphate oxygen isotopes

To reveal functions of the lagoons of the lake Biwa with nutrient remediation purpose, inflow and outflow of the lagoons will be researched. Nutrient contents, water quality and especially phosphate oxygen stable isotope signature of water samples will be investigated. With consideration of flow amount (hydrology), we will be able to define remediation ability of lagoons and their roles in nutrient composition changes. By analyzing δ18Op data, stable isotope signature of oxygen will be determined. As theoretical isotopic equilibrium value for oxygen is known as: T(°C) = 111.4 - 4.3(δ18Op - δ18Ow)  where δ18Op is the oxygen isotopic composition of phosphate expected at equilibrium, δ18Ow is the oxygen isotopic composition of the water, and T is the temperature of the water - we will be able to determine biological P cycling in lagoons. Biological cycling will make δ18O closer to the equilibrium value, and will tell contribution of life forms in P retention. This result will tell us which lagoons are in good function and which lagoons are degraded. Also, a Mesocosm research will be conducted to evaluate exact portion, roles and synergy effect of plants and bacteria.