Seasonal variations of phytoplankton community structure in relation to physico-chemical factors in Lake Baiyangdian, China.

Abstract: In order to study the seasonal variations in the structure and dynamics of phytoplankton community of the Lake Baiyangdian in China, quantitative samples were collected in each season during 2005. A total of 152 taxa were identified by microscope, phytoplankton had an abundance ranging from 131.25×10⁴ ind. L^-1 to 745.88×10⁴ ind. L^-1. The highest phytoplankton abundance were observed in spring and the lowest in autumn. Cyanophyta, Euglenophyta and Cryptophyta were the most important groups in terms of abundance and biomass. The preponderant and sub-preponderant species changed in accordance with the seasons. Canonical Correspondence Analysis (CCA) was used to investigate the relationship between environmental factors and phytoplankton community. The results indicated that nutrient gradient had a positive correlation with axis 1 in spring, summer and autumn. But in winter, the nutrient gradient had a positive correlation with axis 2. The varieties of environmental factors affected the structure of phytoplankton community in each season. CCA shows a slight, but significant method to understand the spatial distribution of phytoplankton community in lake systems. [ABSTRACT FROM AUTHOR]