Population Structure and Diversity of Plankton in the Wetland of Qilihai in Tianjin

The population structure and diversity of plankton in the wetland of Qilihai in Tianjin was investigated in May, July and September, 2012 by fi eld investigation and sampling examination. The results showed that there were 44 species of phytoplankton belonged to 6 phyla, including 11 species of Cyanophyta, 18 species of Chlorophyta, 8 species of Bacillariophyta, 4 species of Euglenophyta, 1 species of Pyrrophyta and 2 species of Cryptophyta. There were 13 genus and 22 species of zooplankton, among which 4 genus and 4 species belonged to Cladocera; 2 genus and 2 species belonged to Copepoda; 7 genus and 16 species belonged to Rotifera. The investigation results of density and biomass of plankton in May, July and September showed that the density and biomass of phytoplankton was shown as September>July>May, and that of zooplanktonic was shown as May>September>July. In addition, the diversity of phytoplankton and zooplanktonic were evaluated using Shannon-Wiener index, and the results demonstrated that the phytoplankton species were rich in May, July and September, while the zooplanktonic species were poor in May and general in July and September. There were explicit relationships between the diversity characteristics of plankton and nutrient pollution which caused water eutrophication, and the extent of water eutrophication in the different months was also shown as May>July>September.

Assessment on Qilihai Wetland Value in Tianjin City

[Objective]The study aimed at assessing the whole value of Qilihai Wetland in Tianjin City.[Method]In this study,the whole value of Qilihai Wetland was divided into two parts,namely use value and non-use value.The use value of Qilihai Wetland was estimated by market value,travel cost,shadow project method and so forth,and the non-use value of Qilihai Wetland was assessed by contingent valuation method.[Result]The total value of Qilihai Wetland reached 1.892 billion yuan,wherein the direct use value,including animal and plant products,tourism,scientific and cultural value,was 0.539 billion yuan,accounting for 28% of total value;the indirect use value,composed of functional values in hydrology,water quality,erosion control,CO2 fixation and habitats,was up to 0.965 billion yuan,making up 51%;the non-use value totaled 0.388 billion yuan,taking up 21%.In addition,the ecological benefit of Qilihai Wetland was the maximum,accounting for 72% of total benefit,followed by economic benefit（21%）,while the social benefit was the minimum（9%）.[Conclusion]The results can provide scientific references for the effective conservation and sustainable utilization of Qilihai Wetland.