Fine-scale Evaluation Of Giant Panda Habitats And Countermeasures Against The Impacts Of Future Climate Change

Climate change has become one of the major threat to biodiversity in the 21 st century.There were massive observed proofs showing that climate change together with other stressors have led to the shifts of species’ distribution range,the changes of wildlife phenology and reproductive behavior,community compositions,and ecosystem functions.These influences particularly serious for species characterized by a limited habitat,small population,low reproductivity,and weak migration ability.The giant panda(Ailuropoda melanoleuca)is one of the most widely recognized threatened mammals and was categorized as Endangered on the International Union for Conservation of Nature(IUCN)Red List,now only confined in six isolated mountains located in Sichuan,Shanxi and Gansu provinces in China.Furthermore,the giant panda habitat are fragmented severely and the conservation status still stern.Detailed and reliable information about the adverse effect of future climate change on giant panda habitats is necessary and urgent,and the responses of habitats to climate change attract substantial attention from researchers.However,most efforts are focused on medium or large scales.e.g.,the whole gaint panda distribution areas or some special mountains.This is problematic because the results are difficult to be translated into viable decisions.Moreover,multiple factors may introduce uncertainty into projections of species distribution under climate change background,but there are few studies to comprehensively analysis and compare the likelihood uncertainties.In order to fill this gap,this study used the latest fourth survey data of the giant panda together with the most widely used maximum entropy model(Max Ent),based on remote sensing,geographic information system and other space technology,to evaluate the giant panda habitat suitability both at present and in the 2050 under the climate change scenario.We carried out the evaluation at two different levels,the whole Sichuan giant panda habitat and the core area of giant panda habitat,namely,the Ya’an prefecture.Firstly,we compared four major uncertainty datasources when using ecological niche models to forecast the future species’ distribution,including the selection of the base climate dataset(WorldClim dataset and the climate dataset acquired by remote sensing technology),the environment variable selection approach(correlation-variable contribution(CVC)and principal component analysis(PCA)),4 different global circulation models(BC,CC,CN and HE)and two representative concentration pathway(RCP2.6 and RCP4.5),then we used the optimized approach to do the following evaluation.During the evaluation process,we used six kinds of data.The latest giant panda occurrence data and the human disturbance factors were based on the 4th survey report on giant panda in Sichuan Province.Elevation,slope and aspect were employed as physical environment factors.The distribution of the bamboo and the distance to drainage were used as biological factors.The human disturbance factors included roads,mines,hydropower stations,power transmission lines and scenic spots which often occurred within the study area.Bioclimatic factors obtained from WorldClim website.Multi-source remote sensing data included the NDVI data from 2001 to 2015,the 12 consensus land cover layers and other high resolution remote sensing data,such as GF-1.This study demonstrated that the impact trend and intensity of climate change was different as for different research level.At the whole Sichuan giant panda habitat level,the suitable habitat will decrease in 2050,the decrease rate within 10%.At the same time,the impact of climate change is different within different mountains.The suitable habitat in Liangshan mountain which located in the south and the northeast part of Minshan mountain which located in the north will has a little increase,while the suitable habitat will be significantly reduced in Daxiangling mountain and in the northeast of Xiaoxiangling mountain,which both located in the south of our study area.As for Ya’an research area,(1)only considering climate change,the overall habitat that can be used by giant pandas will increase,which differs from most of the previous results which showing a decrease trend;(2)the new suitable habitat will shift westward,northward and eastward in this region,the Baoxing county located in the northwest,Tianquan county located in west,Lushan county which located in the east of study area both showing habitat increase in the future.These prediction is in accordance with the trend found in the 4th panda servey report;(3)conversely,the suitable habitat will be significantly reduced(about 58.56%)and fragmented when taking into account human disturbance factors;(4)at present,the three small nature reserves within Ya’an study area are far from each other and cannot cover the present habitat well nor protect the potentially suitable habitats in the future.Based on the comprehensive analysis of habitat shifts and our two field investigations,this study provided corresponding protection suggestions on two research levels.Furthermore,we used a geographical information system to incorporate high-resolution remote-sensing images from the GF-1 satellite,land-cover maps,and digital elevation model to verify the possibility of our suggestions in fine-scale level.The results can provide necessary information to help the decision making of protection and management departments.In addition,the research method and technical route of this paper are also applicable to the analysis and evaluation of other animals and plants.We hope that this result can contribute a little to the protection of biodiversity and the construction of ecological civilization in China.