Spatial Distribution Of Spring Phytoplankton Community In Liuxihe Reservoir, South China

Phytoplankton are the main primary producers in aquatic ecosystems, their standing stock and species diversity are indicators of water quality, and the heterogeneity of the community structures provides spatial variability in their responses to environmental variables. To investigate the potential spatial pattern, spring phytoplankton were sampled in 30 sampling sites from riverine zone to lacustrine zone in Liuxihe Reservoir(a large reservoir in South China) in January and March, 2014. Phytoplankton were grouped in four zones. This study also aimed to understand the heterogeneity of spring phytoplankton community and the main explanatory variables in the large and deep reservoir with multivariate statistical methods. The result showed that:1. Chlorophyll a concentration had a spatial pattern: riverine zone > reservoir bay >lacustrine zone > transition zone in January, explained together by environmental variables, zooplankton variables and spatial variables in January, and riverine zone > transition zone > reservoir bay > lacustrine zone, mainly explained by spatial variables in March. 2. Phytoplankton diversity had a spatial pattern: reservoir bay > riverine zone > lacustrine zone > transition zone, mainly explained by environmental variables in both January and March. 3. Phytoplankton community was affected by spatial variables, its Bray-Curtis dissimilarity had a pattern: riverine zone > lacustrine zone > transition zone > reservoir bay in January and riverine zone > reservoir bay > lacustrine zone > transition zone in March. 4. The spatial distribution of phytoplankton community became more complicated with increasing temperature and dynamics. The explained variation of phytoplankton community decreased and spatial variables played more important role in structuring the phytoplankton community in March.