Study On Wetland Bird Community And Influencing Factors Of Habitat Selection In Shiyang River Basin, Minqin County

The Minqin Shiyang River Basin,one of the areas that suffer from the most serious drought and desertification,and one of the four major sources of sandstorms in China,is located at the eastern end of the Hexi Corridor in Gansu Province.Owing to extending from the southwest to the northeast,the wetland of the basin naturally separates the Badain Jaran Desert from the Tengger Desert,and effectively prevents their convergence.The basin,a shining pearl of the wind and sand line in the northeast of the Hexi Corridor,acts as a natural barrier against sandstorm stress.As a typical representative of wetland in arid areas,the peculiar ecosystem and climatic surroundings have given birth to a considerable part of wetland bird resources.However,the studies about wetland aves of the basin are deficient in diversity and habitat selection.The author used the line-intercept method to investigate the aves resources in the wetland of the basin from July 2016 to August 2018.Meanwhile,four typical wetland types were selected,and the influencing factors of habitat selection were carried out on 20 fixed samples.A whole variety of approach,such as canonical correspondence analysis(CCA),SPSS and “Biodixcel for Excel 2007” were used for data processing.As a result,the following results are obtained:1.A total of 92 species of birds are recorded,which belongs to 16 orders and 38 families.According to avifauna,the Eurytopic species occupies a dominated position with 76species(82.61%),16 species(17.39%)in the palaearctic realm.In terms of residence type,41species(44.57%)of summer visitor,which is the most species;36 species(39.13%)of resident birds;8 species(8.70%)of winter visitor species,and 7 species(7.60%)of migrant species.Breeding aves(including summer visitor species and resident species)account for the majority with 77 species(83.70%),reflecting the basin plays an important role in breeding of wetland birds.2.There are 3 species of aves,which pertain to first-grade State protection wildlife,and12 species of aves belong to the second.There are 7 species of Near Threatened(NT)species and 6 species of Vulnerable(VU)species in the Red List Categories and Criteria of China,of which the number of Cygnus cygnus is the highest(RA=1.97%).One species is endemic to China-Garrulax davidi.3.The seasonal dynamics of aves are obvious.In terms of quantity,the number of birds in the migration month(March to April and September to October)is enormous.As far as diversity is concerned,aves of summer have the highest diversity index(H=3.587)while the lowest in winter(H=1.763).4.Four typical wetland types were selected.The abundance of different types of wetland species in the same season shows a regular pattern,artificial wetland> river wetland>lake wetlands> marsh wetland.Smith similarity analysis was carried out on bird community structure in four different habitats,and cluster was carried out using SPSS 20.0 software.Eventually,CCA analysis is carried out on habitat characteristics via using Canoco 4.5software.The result shows that the similarity between lake wetland and artificial wetland is the highest,and the species diversity between marsh wetland and other wetlands is quite different..5.The distribution of waterbirds is closely related to the type of land cover.Waterbirds can be partitioned into three groups according to habitat utilization.The first is waterfowl represented by the waders,which are mainly distributed on the shoals of marsh wetland near Qingtu Lake;The second is the waterfowl of fragment-habitat that eating plants,which is represented by the Coot and Anatidae,mainly distributed in plant-rich wetland,corresponding to artificial wetland;The carnivorous birds that live around humans,represented by the gulls and cormorant,are mainly distributed in the densely constructed fishing areas opened by humans,corresponding to lake wetland and artificial wetland.6.Based on the analysis of this survey,in accordance with habitat selection of wetland bird,it is believed that the current primary problems faced by the wetland including: climate changing,population growth,road construction,garbage pollution and chaotic mining,and some targeted protection measures are put forward.