| The Hulan Estuary Wetland along the bank of the Song Hua Jiang River is protected more completely, belonging to swamp wetland with the bigger water areas and rich biodiversity. But in recent years, the waters area is increasing due to human activities intensify, so the biological communities constituted a wetland ecological system also are experiencing complex changes, which can affect the survival about the composition, tructure and function for macroinvertebrate community and fish community.On the basis of wetland ecosystem in The Hulan estuary wetland, investigated the macroinvertebrate community, fish community and environmental factors such as water quality status, combining mathematical analysis methods and statistic model, analyzed the relationship between the macroinvertebrate/fish and the environmental parameters. Water ecosystem health of was assessed using Index of Biotic Integrity (IBI).Main conclusions from the four parts of dissertation were drawn:1. The composition structure and temporal-spatial characteristics for macroinvertebrate community(1) The basic composition of macroinvertebrateA total of167species were recorded, including aquatic insects121species, Oligochaeta23species, Mollusks16species, Hirudinea5species, Carapace class2species. Different waters had its dominant species, such as:Limnonodrilus hoffmeisteri, Branchiura sowerbyi, Cricotopus sylvestris and Stictochironomus maculipennis.(2) The composition of macroinvertebrate feeding functional groupThere are six kinds of feeding functional groups. The study shew that the feeding functional groups analyzed indicated that the functional groups were differences with the temporal and spatial, and gatherers-collectors were main feeding functional group for the whole research areas in spring, and the filterers was main feeding functional group in Ashihe (ASH) River upsteam in fall.(3) The distribution pattern for macroinvertebrateThe total density distribution patterns of benthic macroinvertebrate were simulated by AcrView (312) software. The biomass distribution pattern for oligochaeta was the largest concentration of patches in DadingShan sampling site, which is closely related to aqutic oligochaeta are adapted to live in the environment rich silt sediment with organic matter.2. The relationship between macroinvertebrate and main water environmental parametersThe ecology characteristics of macroinvertebrate species were analysized using typical correspondence analysis method (CCA analysis), and the results showed that water temperature was the main environment factor for influence macroinvertebrate, followed by water depth, total phosphorus, total nitrogen, nitrate nitrogen (NO3--N) and conductivity.3. The assessment of the integrity of wetland ecosystem using benthic index of biotic integrity (B-IBI) in Hulan Estury wetland(1) Establishing B-IBI evaluation parametersThrough the discriminant power analysis by candidate biological parameters of, sensitivity analysis and Pearson’s correlation analysis, as the result, the benthic index of biotic integrity (B-IBI) was composed by six metrics:Total number of taxa, EPT taxa, Ephemera%, Clingers%, Gatherers-collectors%, Intolerant taxa%and Biotic Index(BI).(2) The establishment of health assessment5lever criteria for water ecosystem based on B-IBI.The establishment of health assessment5lever criteria for water ecosystem using Ratio Method and Three Points Method. The former:>3.56, health;2.67～3.59, sub-health;1.78-2.66, good-fair;0.89～1.77, fair;<0.88poor; the latter:> health;20～26, sub-health,13～19, good-fair;7～12, fair;<6poor.The correlation between two scoring method and four scoring method was0.891. Therefore, the two methods were suitable for water ecosystem health assessment in the Hulan Estury wetland and the surrounding waters.(3) Health assessmentThe water ecosystem health was assessed based on the establishment standard above-mentioned in the Hulan Estury Wetland and the surrounding waters. The result indicated that there was no difference in the assessment result between Ratio Method and Three Points Method. All references were health. Hulan Estury Wetland was the condation from good fair to sub-heath.4. The assessment of the integrity of wetland ecosystem using Fish Index of Biotic Integrity (F-IBI) in Hulan Estury WetlandFish Index of Biotic Integrity (F-IBI) is a kind of valid evaluation, which can reflect current damaged condition of the aquativ ecosystem in a great extent for Hulan Estury Wetland.(1) The fish species composition and richness characteristicsThe invesgation result indicated that there were61species, belonging to8orders,14families, among them Cypriniformes fish species most,42species, which accounted for68.85%of all species. Fifteen fish species had not been found compared with the historical data. There were two exotic fish (such as:Aristichthys nobilis and Rutilus rutilus lacustris), and dominant species were composed of some small-sized and lower-economic value fish species.(2) The characteristics for fish trophic level Invertivores, insectivorous, top-piscivores and detritivores for the main preference food according to the analysis with feeding functional group; planktivorous, herbivorous, zooplanktivorous and phytobenthivores fish were secondary feeding fish. Therefore, fish of primary consumers were relatively less, species diversity is lower, and top consumers, the numbers of secondary consumers and detritivores fish species species diversity are higher in the Hulan Estury Wetland.(3) The fish tolerance and wetland health statusFrom the tolerance for fish faced with water eutrophication, tolerance species were dominant, intolerant and intermediate were subdominant, very tolerant fish were less. The results showed that aqutic ecosystem health was condition from fair to good fair in Hulan Estury Wetland. The analysis indicated that the integrity fish damaged were correlation human activities, such as building dam and mining sands.This study provided the theoretical basis for the biodiversity protection and ecological monitoring in Hulan Extury Wetland Natural Reserves, and the scientific evidence for water ecosystem health evaluation and wetland ecological restoration for wetland natural reserves. |
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