The development and persistence of alternative ecosystem states in a large, shallow lake

摘要: SUMMARY 1. Palaeolimnological data were used to investigate drivers of the community primary producers in Lake Mattamuskeet, North Carolina, U.S.A. This is a large, shallow lake with two basins currently dominated by phytoplankton and macrophytes. The divided 1940 building roadway across lake, which also corresponded divergence their ecosystem state. 2. Photosynthetic pigments, organic matter nutrients (P, N, C, S) analysed sediment cores from each basin reconstruct producer over past c. 100 years. We sought answer questions. First, what changes resulting caused development different communities basins? Second, why have alternative states persisted despite variety human perturbations since 1940? 3. K-means cluster analysis principal component applied identify three types based on photosynthetic pigment data: sediments indicating low productivity (low concentrations), associated macrophytes (chlorophyll b) (alloxanthin aphanizophyll). In addition, other palaeolimnological proxies measured, such as loss ignition, total phosphorus, carbon ⁄ nitrogen nutrients, post1940 within basins. 4. These differences suggest characteristics, nutrient cycling, water depth physical construction, combined establish maintain differing Furthermore, Fe S dynamics waterfowl herbivory probably contributed states.