Scale‐Related Contribution of Environmental and Spatial Processes to Structuring Phytoplankton Assemblages

Abstract

To understand whether the relative roles of environmental control and spatial processes on phytoplankton community structure vary spatially, we collected species and environmental data in August 2010 from three hierarchical spatial scales (basin, region, and sub‐region) from the Huai River Basin, China. We assessed the importance of environmental control and spatial processes in structuring phytoplankton community at the three scales, respectively. Using the method of variation partitioning, we partitioned the community variation into fractions attributable to pure environment variables, pure spatial variables (constructed by Moran's eigenvector maps), and both space and environment. We found that the importance of pure environmental control in phytoplankton community increased with decreasing spatial scales, while the importance of pure spatial processes increased with increasing spatial scales. There was no clear relationship between spatial scale and the variation that related to both space and environment. The relative importance of environmental control and spatial processes is not only related to spatial scale, but also to region context. To predict the importance of spatial and environmental variables in structuring phytoplankton communities in streams, the spatial scale needs to be considered.