| Since the 1950 s,the rate of climate change has accelerated,and life is inevitably affected by climate change.Climate change,together with other factors such as habitat fragmentation and loss,will have a great impact on species with small population size,small distribution range,weak migration ability,single feeding species and poor genetic ability,and may even lead to species extinction.Therefore,the study of wildlife habitat changes under the background of global warming has always been a hot topic for scholars at home and abroad.In recent years,niche models have been increasingly applied to the study of wildlife habitat change,such as calculating potential distribution of species,predicting future habitats of species,and responding to climate change.As China’s "national treasure",the giant panda is a unique endangered wild animal in China.In the past hundred years,due to the influence of human activities,climate and environmental changes,natural enemy diseases and natural disasters,the distribution area has been shrinking,and now it is only confined to the high mountains and valleys in the border area of Sichuan,Shaanxi and Gansu provinces.For a long time,the survival and protection of giant pandas have been concerned,but the giant panda habitat in Gansu Province,located in the north of the Minshan Mountains,is the distribution area of wild giant pandas that has been studied and paid the least attention,and the assessment and prediction of the giant panda habitat in this area is still in the blank stage.Coupling model adopted in this paper,the international comparison program(CMIP5)involved in the global climate models,collecting and processing and distribution of the giant panda in gansu province is closely related to the physical environment factor,climate factor,biological factor,human factor,such as complementary with multi-scale,long time series,the multi-source remote sensing data and its related products,which has been widely applied based on the niche model(MAXENT model),in the context of global warming,the giant panda habitat in gansu region evaluation and forecasting,conservation strategies in order to take the initiative to slow or reduce the negative impact of the future climate change on the giant panda species It provides scientific reference for the formulation of wild giant panda protection program,the planning of future reserve scope,and the establishment of habitat management strategy in Gansu Province.The evaluation system of habitat suitability for giant pandas was established in this paper.In this system,the physical environment factors are altitude,slope and slope aspect.The distance between the selection of biological factors and the staple food bamboo and water,vegetation coverage and vegetation type;Human factors selection of roads and human activities;Isothermal climate factors were selected,including the warmest month,the highest temperature,the average annual precipitation,and the driest monthly precipitation.Among them,biological factors accounted for the largest weight(0.555),followed by topographic factors(0.246),and climate factors accounted for the least weight(0.057).11.38% of the total area was evaluated as the most suitable area for giant pandas to live.Affected by the terrain,the suitable area is divided into north and south,and the northern patch is seriously broken.Then,the habitat change of bamboo forest and giant panda was analyzed and predicted based on MAXENT model.The results show that the total area of bamboo suitable area is 11887.69km2,and the total area of bamboo suitable area will decrease to 7372.57km2 in 2070 under the high emission scenario,which is equivalent to a reduction of more than one third of the total area of bamboo suitable area.Most of the new suitable areas appear in the east and south of the original suitable areas,a large number of suitable areas in the north will face the risk of disappearing,and there will be faults in the middle of the suitable areas.Giant pandas are mainly distributed in Wenxian County,Zhouqu County and a small part of Diabu County,with a total area of 6271.25km2.On the whole,the suitable area will increase slightly at first and then decrease greatly.The center of gravity in the suitable area will continue to remain in Wenxian County,but under the RCP4.5 emission scenario,the moving direction of the center of gravity in the suitable area for bamboo forest and giant panda will shift in the future,and then the giant panda’s main food bamboo resources will be threatened.In the future,the newly added suitable areas will mainly be in the northeast of the original suitable areas,while the protection of giant pandas in most of the areas there is still in the blank stage,and the degraded suitable areas have not attracted enough attention.In addition,this paper also calculated the landscape pattern index of giant panda habitat,and pointed out that there is a risk of degradation of giant panda habitat.At present,the number of patches in the suitable area for giant pandas is large,the density is large,the maximum patch index and the average patch area are small,and the suitable habitat for giant pandas is more fragmented than that of the whole study area.It is predicted that the number of patches will increase,and the maximum patch index will decrease year by year.Under the high carbon emission path,the average patch area will decrease sharply to less than 1km2 by 2050.The living environment of giant pandas will show a trend of degradation,aggravating fragmentation,reducing the ability of inter-population communication and reproduction,and increasing the risk of species extinction.On the basis of the above research,the geographical distribution of the potential corridors for panda migration is planned.A total of 24 ecological corridors are proposed to connect the isolated habitat patches into a network of connected habitat corridors,which is conducive to the migration,foraging,reproduction and protection of giant panda population. |
