Study On The Relationship Between Avian Community And Habitats And Conservation In Wuhan Chenhu Wetland

Wuhan Chenhu wetland is situated at the trigonal area between Yangtze river and Hanjiang river, which is the most important wintering district for migratory birds in Hubei provience. From the last 80th', many ornithologists have investigated in Chenhu , however most of them focused on the rare waterfowls. In order to find out the status of avain habitats, the composing and dynamic of avain community, their relationship with surrouding, a survey wase conducted on Chenhu avain community and their habitats form February 2004 to April 2005. The main results are given as follows:1.The structure of wetland avian community. Total of 138 bird species were recorded, belong to 14 orders, 40 families. Expect for Passeriformes, Anseriformes Charadriiformes Ciconiforms are dominant orders, the species number are 19 species, 18 species and 15 species respectively. Besides, 8 species in Gruiformes, 7 species in Falconiformes,5 species in Lariformes, 4 species in Coraciiformes, 2 species in Galhforms, 2 species in Piciformes, 2 species in Cuculiformes, 2 species in Columbiformes, 2 species in Podicipediformes, 2 species in Pelecaniformes Which 3 species were first-class of National Protected bird and 11 species were second-class of National Protected bird, 9 species were list in IUCN.Four species were new records in Hubei province, say as PALLAS'S GULL(Larus ichthyaetus) and WHIMBREL(Numenius phaeopus) .2.Analysis about the seasonal dynamic of avian community by groups, such as Herons, Ducks and Shorebirds. There are annual fluctuation from winter to summer . Compared and divided the dominance of waterfowl community in winter and summer, the dominant species in winter are Bean Goose(50.5%), Northern Lapwing(10.4%). The dominant species in summer are Whiskered Tern(23%) Cattle Egret(13.2%) and Chinese Pond-Heron(14.%).3.The vegetation in Chenhu Wetland could be divided into 11 Association. They are Carex argyi Ass.(2237 hm2), Miscanthus sacchariflorus + Phragmites communis Ass.(1088 hm~2) Lapsana apogenoides Maxim+Ranunculus polii +Alopecurus aequalis SobolAss.(104.9 hm2), Artemisia selengensis Ass.(28.46hm2), Zizania caduciflora Ass. (270.44 hm2), Typha angustifolia Ass. (6hm2), Trapa bispinosa + Trapa quadrispinosa + Hydrocharis dubia Ass. (67.09 hm2), Nelumbo nudfera + Euryale ferox Ass. (316 hm2), Polygonum hydropiper 1.(238.77 hm~2) Patamogeton crispus Ass.(65.07 hm~2) Nymphoides peltatum +Trapabispinosa -Trapa quadris pinosa Ass.(4735 hm2). Draw the sketch for vegetation distribution based on GPS waypoint and sampling.4.1t was found some wetland plant association disappeared or dwindled in the last 20 years. The coverage ratio of submerged vegetation dwindled from 12.35% to 0.96% ,the coverage ratio of emergent vegetation dwindled form 51.81% to 34.86%(the ratio of vegetation area to the whole lake area). It could be concluded that violent human disturbance ,such as cofferdam and embankment, overbreeding aquatic, dragging for mussels ,led the diversity loss in the lake.5. Comparison on Species Richness, Diversity, Dominance and density of winter avian community in 7 kinds of habitats. Analysed the distribution and character of avian community in different habitats. The sequence of density was: MM(Meadow Marsh) >OWA(open water area) >SL(Shore land) > >SB(Shrubbery) > FP(Fishpond) > Meadow ,among them the density are 15.10ind./ hm2, 9.89ind./hm2, 9.26ind./hm2, 9.19ind./hm2, 3.20ind./ hm2, 1.72ind./hm2 respectively. The sequence of diversity was: MM(Meadow Marsh) > SB(Shrubbery) >OWA(open water area)>SL(Shore land)> FP(Fishpond) >Meadow.6.The historical variation of Composition of Waterbirds community. It shows that the species and population of Waterbirds declined seriously in last 20 years, Among them the population of rare waterbird and Ducks declined notablely. Total of 9 species of rare birds in historic records were not found in this investigation, such as Whistling Swan, Baer's Pochard, Mandarin Duck, Siberian Crane.7.Discussed the relationships of variation of wetland avian community with habitats changes. Compared the waterbird community of Chenhu with Wangjiashe in different environmental factors. It shows that the water depth, vegetation types and coverage determine the distribution and richness of food together.8.Base on the result of investigation, the main threats faced with Chenhu wetland were: cofferdam and embankment, overbreeding aquatic, the destruct of Wetland vegetation and fish diversity, poach and herd. Upon that gived some protection suggestions accordingly.