Relationship between phytoplankton quantity and its environmental factors in wetland of cold regions in spring and summer based on the grey association analysis

The purpose of this paper was to provide basic information for management and a foundation for the future study in ecosystem dynamics and eutrophication on cold regions wetland based on studying the correlation of phytoplankton quantity and its environmental factors. An investigation on the phytoplankton quantity and environmental factors on Anbanghe wetland, a type of cold region swamp in northeast of China, was conducted during July (summer) 2005 and May (spring) 2006. There were 92 common species occurred in both seasons, among which 37 taxa and 82 taxa were identified in spring and summer, respectively. In spring the average abundance was 268.45104 indL-1, and in summer was 268.45104 indL-1. The temporal distribution of amount was summerspring, and spatial distribution was upstream region downstream region, and edge areacore area. The temporal and spatial variation of environmental factors among sampling station and seasons was regular except the diaphaneity and pH. The biggest difference in distribution of environmental factors was PO4-P. The result of grey association analysis showed that the highest value of grey association degree is in PO4-P both in spring and summer. All of these indicated the factor which seriously influenced phytoplankton quantity was phosphate. Thus, it is important to control the phosphate input to maintain ecosystem health of Anbanghe wetland.