[午餐交流会] 第七十五讲：Studies of sedimentary organic matter and phosphorus in lakes, rivers and coastal zones Luncheon Seminars #75: Studies of sedimentary organic matter and phosphorus in lakes, rivers and coastal zones
A3-206 Zhou Long Quan Building
Dr. Loh Pei Sun
Zhejiang University China
【邀请人 Host】：Dr. Raj Kankasamy
Some of my previous researches have been using lignin-derived phenols, C/N ratio and stable carbon isotope to study the sources, distribution and fate of terrestrial organic matter in Lochs Creran and Etive, the Kapuas and Kaoping Rivers, along the northern Bering and Chukchi Seas and the Andong salt marsh system. The relatively fresher terrestrial organic matter from the rivers most likely fueled the biogeochemical cycling in the lochs. The abundance and composition of the lignins were closely related to the deforestation activities and human population within the vicinities of the river banks along the Kapuas and Kaoping Rivers. Stronger terrestrial organic matter signal was observed at the eastern part of the northern Bering Sea near the Yukon River; the Chukchi Sea seemed to be receiving organic matter from more sources. The Andong salt marsh sediments showed strong terrestrial organic matter signal, leading us to imply that lower marsh accretion due to reduced sediment input could be counterbalanced by increased erosion. Studies of internal phosphorus (P) loading showed different P dynamics in Lakes Simcoe and Winnipeg. During fall 2011, sulfate reduction, followed by P and Fe release, occurred in the sediments in Lake Simcoe, but the sulfate reduction in Lake Winnipeg was not accompanied by much P release as the high Al concentrations most likely absorb P.