The Impact Of Climate Change On The Potential Suitable Habitat Of The Relict Plant Silver Fir And The Analysis Of Its Habitat Fragmentation

Global warming is one of the main trends of climate change in the future.As the most direct and obvious response to climate change,the spatial distribution pattern of species will also produce a series of changes.The relict plants are an ancient plant group,also known as living fossils.They have witnessed the biological evolution history of the earth,and have important scientific value for the study of paleontology,palaeoclimate,paleogeology,and paleoecology.In this study,we use the relict plant,Cathaya argyrophylla,to construct the response relationship between the species distribution and the climate change based on the sample points and the 19 bioclimatic factors(bio1-bio19)of the current period,and then predict the potential suitable habitat of Cathaya argyrophylla and determine the dominant environmental factors and the most suitable habitat conditions based on the MaxEnt model and the GIS spatial analysis technique.Secondly,the climatic data of the three past periods(LIG,LGM and MH)and four emission scenarios(RCP.2.6,RCP 4.5,RCP 6 and RCP 8.5)under two future periods(2050s,2070s)provided by IPCC are used to simulate and predict the potential suitablehabitat of C.argyrophylla in the past and future periods.Then,we analyze the effects of climate change on the potential distribution of C.argyrophylla by exploring the characteristics of habitat transfer and centroid transfer trajectory of three time periods.Thirdly,seven indicators of landscape index were used to analyze the change of habitat fragmentation of C.argyrophylla suitable habitat for future climate change.Last,protect critical area and protect sensitive area of C.argyrophylla were identified by superimposing the suitable habitats of current and future periods to provide the theoretical basis for its habitat protection,biogeography,protection and sustainable utilization.The main conclusions are as follows:(1)The potential suitable habitat of C.argyrophylla in the current period is mainly distributed in the area of eastern Sichuan parallel ridge Valley,Wuling mountain,Miao Ling and the Five Ridges,including Sichuan,Guizhou,Guangxi,Hunan,Chongqing and Hubei provinces.The suitable habitat area accounts for 14.38%of the total area of the study area.(2)The dominant climatic factors affecting the distribution of C.argyrophylla are bio 14,bio 2,bio 10,bio 9,bio 4,and bio 12.The most suitable habitat conditions for C.argyrophylla:bio 14 ? 20 mm;bio 2?7.5?;bio 10 is 23?;bio 9 is 6?,and bio 12 is 1300 mm.(3)The influence of climate change on the potential distribution of Yinshan is mainly manifested in the area change,the characteristics of suitable habitat change and changes of centroid of suitable habitat for C.argyrophylla.From the past period to the current period,the suitable habitat area of C.argyrophylla.was reduced first and then increased and last reduced;From the current to the future,the suitable habitat area of C.argyrophylla was increased first and then decreased.the suitable habitat of C.argyrophylla vulnerable to climate change mainly located in Ridge and Valley Province of Chuandong,Wumeng Mountain,Mount Fanjing and Mountil Leigong,Luoxiao Mountains,Tianmu Mountain and HuaiYu Mountain.From the past period to the current period,the centroid of distribution of C.argyrophylla first transfer to the northwest,and then to the east end last to the northwest;From the current period to 2050s,the centroid moving towards lower latitudes under four emission scenarios,from 2050s to 2070s,the centroid keep the direction of the previous period under three of four emission scenarios except RCP 6.0.(4)The effect of climate change on habitat fragmentation of C.argyrophylla mainly reflected on the weaken of polarization phenomenon of habitat fragmentation of C.argyrophylla,and higher overall fragmentation.(5)protect critical area of C.argyrophylla.under 2050s and 2070s mainly distributed in 24-31°N and 106-115°E located in WuYi Mountains,Xuefeng Mountain,Miaoling and the Five Ridges.The areas under two perriods were 429 991 km2 and 410 770 km2.Protect sensitive area mainly distributed in Wumeng Mountain and Zhejiang-Fujian hilly regions,the area of protect sensitive area were 415 957 km2 and 411 445 km2...