Environmental Adaptability And Habitat Corridor Identification Of Marco Polo Sheep Under Climate Change

One of the threats for biodiversity decline and species extinction is climate change.The study of the impacts of climate change on the habitats of species,especially the habitats of endangered species,is of great significance to the future protection of species diversity and the preservation of ecosystem functional integrity.We used the maximum entropy model(MaxEnt)and selected 26 different environmental factors that may influence the distribution of the Marco polo sheep(Ovis ammon polii or Ovis polii)to simulate the distribution of its potential habitat in Taxkorgan Wildlife Nature Reserve in Xinjiang(eastern Pamirs)under the current climate conditions(1950-2000).The Marco polo sheep future potential habitats were also predicted in two periods under the scenarios of RCP2.6,RCP4.5 and RCP8.5 greenhouse gas emissions.Furthermore,we evaluated the performance of this model by using the area under the curve(AUC)of the receiver operator characteristic curve.Then the potential habitat corridors for Marco polo sheep in current and future climate conditions were identified by using the Linkage mapper model based on the assessment habitat suitability.The results showed that the average annual temperature in the study area under three greenhouse gas emissions,RCP2.6,RCP4.5 and RCP8.5 will increase while the annual precipitation will decrease compared with the current climate conditions.The results show that the prediction of Maxent is precise and acceptable(mean AUC=0.939).Among the 26 environmental factors,mean temperature of wettest quarter,temperature seasonality,vegetation,min temperature of coldest month,mean temperature of direst quarter,and altitude have great influences on potential habitats for the Marco polo sheep.Under current climate conditions,the area of high suitable habitat of macro polo sheep is 700.44 km~2,the suitable habitat is 767.94 km~2,and the unsuitable area is14394.62 km~2,it accounts for 4.42%,4.84%and 90.74%of the total area of the reserve respectively.With time goes on,the suitable area in current condition is significantly reduced under RCP4.5 and RCP8.5 climate change scenarios,while the suitable habitat area increase under RCP2.6,and the total potential suitable areas is less.The decline in RCP4.5 climate scenarios is higher than in RCP8.5 climate scenarios,and the change of suitable habitat was significantly higher than that of suitable habitat.From 2050s to 2070s,under the climate RCP2.6 scenario,the most suitable habitat area and more suitable habitat area of Marco Polo sheep were 2437.12 km~2 and 2195.51 km~2respectively,and the total suitable habitat area continued to increase.Under the RCP4.5climate scenario both the suitable habitat area and the more suitable habitat area of Marco Polo sheep showed a declining trend.The most suitable area and more suitable area were 344.37 km~2 and 480.40 km~2,which decreased by 0.35%and 2.25%respectively,and the total suitable habitat area continued to decline.Under the RCP8.5,the high suitable habitat area and medium suitable habitat area were 396.05 km~2 and904.18 km~2,which decreased by1.03%and 0.42%respectively.In terms of spatial distribution of the potential habitat for the macro polo sheep,the geometric center of the potential habitat will first move west,and then move southwest.By 2050s,the center of the potential habitat in RCP2.6,RCP4.5 and RCP8.5will shift by 13.67 km,13.69 km and 12.55 km,respectively;by 2070s,the corresponding distance will shift by 27.35 km,15.50 km and 4.14 km.The distribution of potential suitable habitat shows a trend of migration to high altitude and high latitude.With the change of climate,the habitat corridor moves northwest with the change of suitable habitat.In current condition,the corridors on both sides of 314 national highway play an important role in maintaining the network connectivity of the whole landscape,but the quality of the corridors is poor,which requires special protection.In the future climate conditions,because the suitable habitat on the east side of G314largely disappeared,habitat corridor for the entire area plays an important role in the corridor is mainly connect those larger habitat patches,distributed in the both sides of Taxkorgan river.Therefore,these areas for future climate change impact on Marco Polo argali,also need attention.