| Brown eared pheasant(Crossoptilon mantchuricum)is an endangered Phasianidae bird endemic to China has been listed as a vulnerable(VU)globally threatened species by the International Union for Conservation of Nature(IUCN)as a result of population decline and habitat fragmentation.The species is classified as one of the endangered species with the highest priority for conservation in China.Since 1980s,studies of Brown eared pheasant gradually into the biology,ecology,molecular genetics and other fields,but relatively few studies of distribution and protection,be badly in need of attention and research.Using GIS,MaxEnt model and GAP analysis to study the habitat preferences and potentially suitable habitat of this species,the relationship of forest coverage rate and history distribution retreat,can help us to understand the key limiting factors of the threatened species,the distribution of potential suitable habitat,the protection GAP area in the current reserves network,and formulate the corresponding protection measures.By consulted many ancient books and literature to determine its historical distribution from 25 to 1947 CE.The Site Record Database for Chinese Galliformes includes extensive current distributional data.History and current distribution were compared in GIS 10.0.Random forests and TreeNet model were used to analysis the habitat preferences of Brown eared pheasant.Through GIS and MaxEnt model to analysis the change state of historical area,and explore the relationship between forest coverage rate and the distribution of Brown eared pheasant.MaxEnt model and GAP analysis technology analysed the potential suitable habitats of Brown eared pheasant,and nature reserve protection vacancy.Then by discussed the influence of the different sample size,sample accuracy and environmental factors on MaxEnt model prediction effect.(1)Brown eared pheasant prefers coniferous and mixed coniferous-broadleaf forests in 6～16° slope and sunny south-facing aspect of 1600～2100m high altitude.It primarily avoid residential area and roads that are suffering most human disturbance,the recent distance is 0.4 km and 0.6 km away,respectively.(2)The historical distribution range of Brown eared pheasant was determined to be Shanxi,Shaanxi,and Hebei.The current distribution area of this species includes Shaanxi,Shanxi,Hebei,and Beijing.The distribution area had decreased considerably over the past 2000 years.The most serious reduction in the historical distribution area had occurred in Shanxi.The prediction results of the potential distribution of Brown eared pheasant were consistent with historical facts(3)Brown eared pheasant distributed in most districts of Shanxi Province,when the forest coverage of the historical distribution was greater than 10%,and the max-median of the forest cover was 48%.It had absence in northern,northeastern,central and southeastern of Shanxi when the forest coverage rates were less than 10%.The loss of forest resources was synchronous with the reduction of the distribution range of this species,and forest cover decline was closely related to the contraction in its distribution range.Thus the lower threshold of forest cover was considered for ensuring this species’ survival to be at 10%(4)The suitable habitat range of Brown eared pheasant in whole study area covers about 20,744 km2 while the optimum habitat area covered only 2,319 km2 and the moderate suitable habitat area was about 18,425 km2 respectively.Furthermore a large area of suitable habitats distributed north(Shuozhou),northeast(Wutai)and central(Qinyuan)of Shanxi,and some suitable habitats scattered in Hebei outside study area.These eight national reserves network contains around 8.9%of the total area of suitable habitat.There are 1,861 km2 of optimum habitat and 17,035 km2 of moderate suitable habitat which is 9%and 82.1%of the total area of suitable habitat located outside the reserves and need to be protected.(5)Using six combinations based on three sample data sets and two kinds of environmental variables to estimate the potentially suitable areas of Brown eared pheasant in MaxEnt model.MaxEnt model provided different descriptions of potential distributions based on different sample size,sample accuracy and environmental background.The sample and predicting environmental factors must be prudent selected when constructing MaxEnt modelThis is the first study to explore the the relationship of forest coverage rate and history distribution base on GIS and MaxEnt model,acquired the reserve protection gap area,found that forest cover was closely related to the distribution range of Brown eared pheasant,the historical distribution area had decreased considerably,a large area of suitable habitat located outside the reserves and need to be protected.The protection and management of provincial nature reserves and inter-and-extra reserve are both crucial for steady population growth of Brown eared pheasant. |
