Research On Plankton Diversity And Health Assessment Of Zhalong Wetland

Zhalong Wetland, the first to be approved as National Nature Reserve of International Important Wetlands, locates in the juncture of Qiqihar, Fuyu, Lindian and Dumong in Heilongjiang Province. In recent years, due to the global warming, the decreasing of precipitation, and the influence of human acitivies, Zhalong Wetland’s ecological function had gradually declined, taking the form of the shrink of the Wetland area, the drop of water level, and the reduction of birds and fishes, etc.In this paper, seven monitoring sites were established in Zhalong Wetland, including four at the inlet in Zhalong Wetland, two at the core area, and one at the lower Reserve. Based on the qualitative and quantitative analysis of phytoplankton and zooplankton in the summer and fall of2011, this paper applies multidimensional scaling analysis (MDS) and detrended correspondence analysis (DCA) to make a statistic analysis of characteristics of plankton community. This paper also evaluates the health status of water environment in Zhalong Wetland by three plankton biodiversity index.Phytoplankton7phyla60genera and112species (including varieties and forms), zooplankton,3phyla27genera and44species were identified in this survey. Phytoplankton mainly consists of green algae and diatoms. Zooplankton mainly consists of protozoa and rotifers. Zhalong Wetland phytoplankton species number shows a decreasing trend from summer to fall, while the zooplankton species number showes an increasing trend.Throughout the whole year, Zhalong Wetlands phytoplankton has seven dominant species altogether, including five kinds of Bacillariophytas, one kind of Cyanophyta, and one kind of Chlorophyta. Zooplankton, throughout the year, has a total number of eight dominant species, including five kinds of protozoa, and three kinds of rotifers animals. There are seventeen common species of phytoplankton, including four kinds of Chlorophyta, nine kinds of Bacillariophyta, two kinds of Cyanophyta, and of kind of Chrysophyta. Throughout the year, diatoms and green algae are the dominant species of phytoplankton in Zhalong Wetland. There are six common species of zooplankton, including four kinds of protozoa, one kind of rotifers, and one kind of copepods. Common species is the protozoa small bell insects all the year round.Zhalong Wetland plankton biodiversity index greatly differs due to the change of season and site. Because of the seasonal variation, the average of Shannon-weave Index (H’) and Margalef index (d) of phytoplankton is higher in summer than in autumn, while average Pielou index (J’) is lower in summer than in autumn; the average Shannon-weave Index (H’)of planktonic animals, Margalef index (d) and Pielou index (J’) is higher in autumn than in summer, the distinctioin is very small between the two seasons. Base on the multidimensional scaling analysis of Plankton (MDS), this survey generally divides plankton in Zhalong Wetland into three different groups, including1site,2and3sites, and4to7sites. The MDS chart clearly shows that the differences in phytoplankton and zooplankton between each site. This spatial and temporal differences relate to Zhalong Wetland’s hydrologic conditions and aquatic vegetation conditions.Based on the detrending correspondence analysis (DCA) of Plankton species and sites, this paper divides the seven sites of Zhalong Wetland into the Region Ⅰ (Wetland of Artificial Reservoir), Region Ⅱ (Wetland of Natural lake), and Region Ⅲ (Wetland of Alkaline Lake). DCA species sort also divides plankton into three community types. Sign community species Ⅰ is mainly from the oligonucleotide dirt with the common kinds. Community species Ⅱ is mainly oligonucleotide the dirt species to (3-dirt species and wide spectrum of species. Community species Ⅲ is mainly in the dirt for the β-and α-dirt with up to dirt with the species.Health evaluation result shows that the water environment quality of Zhalong Wetland is mainly in oligonucleotide sewage band to β-dirt with a small part in the α-dirt. Although water environment is in good condition, it inclines to transform into moderate pollution. Therefore, in order to prevent further deterioration of the water environment, it is necessary to strengthen the protection of aquatic ecosystems of the Wetland.