Habitat Fragmentation Of Western Crested Gibbion(Nomascus Concolor) In China

Western black crested gibbion,Nomascus concolor,a small ape that mainly distributed in Yunnan,China.It is classified into four subspecies--N.c.concolor,N.c.jingdongensis,N.c.furvogaster and N.c.lu.N.concolor.It was assigned as one of the first class national protected wild animals,and was evaluated as the "Critically Endangered" species in IUCN Red List.Previous studies have focused on population and distribution,behaviour ecology and population genetics.However,the habitat status on landscape scale have rarely been analysed,except for the study on Wuliang Mountain.In order to systematically evaluate the habitat change in past 30 years,we used "3 S" technology and image data from Landsat satelliates to interpret the landcover and landuse classification,and try to explore the intrinsic motive force which result in these dynamic changes.Our study covers 25 counties from 5 prefectures,Yunnan,about 78,000 km2 intotal.We downloaded the winter image data,which contains four periods ranging from 1988,1995,2005 and 2015,from United States Geological Survey(USGS).ENVI 5.2 and ArcMap 10.3 was used for processing and analyzing.Google Earth was defined as a good way to gather a great quantity of samples to interpret the image data,using Example Based Feature Extraction.The accuracy of classification results are about 0.8.The wide and continuous habitat of western black crested gibbion(evergreen broad-leave forest)from the classification results was concentrated in Mts.Wuliang and Ailao that in central Yunnan,Mts.Yongde,Bangma,Xuezhuling,Gengma,Huihan and Wokan that in western Yunnan,Mt.Niuluohe,Huanglian,Dawei,Xilong,Fenzhuiling and Guanyin in southern Yunnan,and the evergreen broad-leaved forest in other areas are seriously fragmented.The patch size and connectivity degree of evergreen broad-leaved forest in Mts.Wuliang and Ailao,the most population(87 groups and 183 groups repectively)inhabiting,are the important habitat for this small ape and well-protected.It is obvious that the evergreen broad-leaved forest in western Yunna was seriously fragmented,conbined with the siginificant increasing of human activity and landuse.They are the partial reasons why the gibbons are not found in some sites in the recent field survey.The landscape indexes were quantified in Fragstats 4.2.The results suggested that the area of evergreen broad-leaved forest were decreasing in the 30 years.What is more,the Number of Patches(NP),representing the landscape fragmentation,were 8127,11127,14577 and 86737 in1988,1995,2005 and 2015.The great increase of NP implied that the evergreen broad-leaved forest has been in a fragmented process,particularly from 2005 to 2015.Available data showed that the smallest home range of a group of N.concolor at Mt.Wuliang is 150 hm2.The continously fragmented habitat would be a major threats to the existence of gibbions.Human activities were the most important reason for the habitat fragmentation of western black crested gibbion in the past 30 years.The behavior of poaching,logging,farming and grazing are still existed.The area of human activity and land use in 2015 increased 18%than in 1988,which implies that human activity separated the habitat into small patches.