| Zhalong wetland is located in Songnen Plain of Heilongjiang Province.Its geographical coordinates are 123°51.5'?124°37.5'E and 46°48'?47°31.5'N.The reserve management bureau is located in Yushugang,Zhalong town,26km southeast of Qiqihar city,and Tiefeng and Angangxi districts of Qiqihar city are in the northwest of the reserve.The administrative divisions include Tiefeng and angxi districts of Qiqihar city,Fuyu county,Tailai county,Lindian county and Durbert Mongolian Autonomous county of Daqing city,with a total area of 2100km2.Due to natural and man-made reasons,the problem of water shortage in wetland is serious.Zooplankton plays an important role in aquatic ecosystem and is an indispensable intermediate link of material circulation,energy flow and information transmission.This study conducted a comprehensive and in-depth investigation and research on the species diversity,community structure and water environment characteristics of zooplankton in Zhalong Wetland in spring,summer and autumn of 2019.1.Community structure of zooplankton in Zhalong WetlandDuring the investigation period,a total of 72 species of 44 genera in 4 phyla of zooplankton were found in Zhalong Wetland,which including 36 species of 20 genera of rotifer,accounting for 50%;20 species of 13 genera of protozoa,accounting for 27.78%;8 species of 6 genera of cladocera,accounting for 11.11%;8 species of 5 genera of copepoda,accounting for 11.11%.The abundance ranged from 1.1 × 103 to 3.42 × 104 ind/L,and the biomass ranged from 0.38 to 19.45 mg/L.There are 17 common species and 14 dominant species.The niche breadth of dominant zooplankton species ranged from 0.04 to 0.65,and the niche overlap value of dominant species ranged from 0.03 to 0.86.The Shannon-Wiener diversity index of zooplankton ranged from 0.75 to 3.47,Pielou evenness index ranged from 0.25 to 0.6,and Margalef richness index ranged from 1.12 to 3.42.The results of water quality evaluation showed that there were occasional light pollution,most of which were moderate pollution.The similarity of zooplankton community in Zhalong wetland was in the medium similarity level and the medium dissimilarity level.2.Characteristics of water environment Zhalong WetlandThe water environmental factors of Zhalong Wetland were significantly different among sampling sites(P<0.01).Four indexes of dissolved oxygen,total nitrogen,total phosphorus and five-day biochemical oxygen demand were selected to the water quality assessment of Zhalong Wetland.The results showed that the water quality of Zhalong wetland was better,most of which were in class ? and class ?.The comprehensive pollution index showed that the water quality of Zhalong Wetland was light pollution or medium pollution.Spearman and RDA analysis results revealed a significant correlation.The main environmental factors affecting zooplankton include EC,T,TP,pH,Cl-,NH3-N and BOD5.3.Construction of zooplankton integrity index in Zhalong WetlandAccording to the relevant standards,9 reference points and 15 damaged points were determined.A total of 24 candidate biological indicators were selected from four aspects,which including zooplankton community richness,abundance biomass,diversity index and nutritional structure.After distribution range analysis,discriminant analysis and correlation analysis,the zooplankton integrity index of Zhalong Wetland was constructed.Finally,the core index was determined to be composed of five biological indicators,including total taxon number(M1),Cladocera taxon number(M4),Cladocera biomass percentage(M12),Margalef richness index(M16)and medium zooplankton predator percentage(M22).4.Water environmental health assessment of Zhalong Wetland based on zooplankton integrity indexThe score standard of zooplankton integrity index in Zhalong Wetland was set by three points method,four points method and ratio method respectively,and the discriminant analysis and correlation analysis were compared in pairs.The zooplankton integrity index in Zhalong Wetland was scored by ratio method and range from 0 to 2.91,which was divided into three equal points,so as to establish the standard of zooplankton integrity index of Zhalong Wetland.When Z-IBI value between 0 and 0.97,which was seriously disturbed.When Z-IBI value between 0.97 and 1.94,which was moderately disturbed.When Z-IBI value ranged from 1.94 to 2.91,which was slightly disturbed.And when Z-IBI value>2.91,which was not disturbed.The results showed that there were 3 sampling sites without interference,10 sampling sites were slightly interfered,10 sampling sites were moderately interfered,and 1 sampling sites was severely interfered.87.5%of Zhalong wetland was disturbed in different degrees,and 12.5%was not disturbed. |
PDF Full Text Request