탄소 및 질소 안정동위원소비를 이용한 팔당호 내 먹이망 구조의 계절 변동 연구

Abstract

To conform the seasonal and spatial variation of food-web structure in aquatic ecosystem, we collected particle organic matter (POM), zooplankton, aquatic plants, sedimentary organic matter (SOM), macro benthic invertebrate (MBI), and fish near the dam of Lake Paldang (LP-1) and the inflow area of South Han River (LP-2) before and after heavy rain season in 2008, Korea. Carbon and nitrogen stable isotope ratio of 81 samples were analyzed by EA-IRMS in Hanyang Univ. SIA result of carbon and nitrogen showed an increase in allochthonous input into Lake Paldang during heavy rain season and LP-2 was more affected than LP-1. And heavy rain affected food web structure, trophic position of aquatic organisms and food web length. Trophic level (TL) and food web length (FWL) reflects the environmental disturbance via heavy rain, because of fluctuation of isotopic values of base of food web. δ15N values of POM and zooplankton dramatically increased by allochthonous input. Also δ15N values of MBI increased by alteration of quality (C/N ratio) of possible food sources. These variation were caused by alteration between autochthonous and allochthonous organic matter in aquatic environment throughout the heavy rain season.