Spatial analysis of phytoplankton patterns in relation to environmental factors across the southern Taihu basin, China

Spatial patterns of phytoplankton across the southern Taihu basin of China were examined through five aspects: abundance, composition, richness, evenness and diversity. Data were collected from 33 sites in the 2010 dry (April) and wet (July) seasons. Global Moran's I statistics and Local Indicators of Spatial Association were used to characterize the spatial autocorrelation for phytoplankton patterns. The phytoplankton pattern was found to have significant spatial autocorrelation in both seasons. Specifically, the wet season showed more local patterns of richness and more regional evenness patterns. Spatial regression models were carried out to identify environmental factors that would control phytoplankton patterns. Results showed that diversity and composition of phytoplankton were significantly related to nutrients. Also, phytoplankton richness could be predicted by potassium permanganate. No significant relationships were identified between environmental factors and phytoplankton evenness in both seasons. Our study highlighted the importance of incorporating spatial dependence when identifying the explanatory environmental factors for phytoplankton patterns.