新疆兔属三物种潜在生境分布及未来气候变化的影响

Potential Habitat Distribution of Three Species of Lepus in Xinjiang and Effects of Future Climate Change

气候变化是导致生境丧失和生物多样性下降的主要因素之一。研究气候变化对物种生境的影响对于保护物种多样性,维护生态系统功能完整性具有重要意义。本研究以新疆为研究区域,以塔里木兔、草兔和雪兔为研究对象,选取可能影响它们生境分布的10个环境因子,利用MaxEnt模型预测它们当前和未来RCP 4.5和RCP 8.5两种气候情景下2041—2060年(2050s)、2061—2080年(2070s)的潜在生境分布,并找出影响生境分布的关键因子。研究结果表明,模型预测新疆兔属3个物种生境分布的精度达到较高水平,塔里木兔、草兔、雪兔的模型AUC值分别为0.955、0.853、0.940。从Jackknife环境变量重要性检验结果来看,影响塔里木兔生境分布的主要环境变量有最冷季均温、年均降雨量、坡度、最干季度平均温度;影响草兔生境分布的主要环境变量有最干月份降雨量、等温性、年平均降雨量、昼夜温差月均值;影响雪兔生境分布的主要环境变量有最干月份降雨量、最干月份降雨量、等温性、昼夜温差月均值。对于塔里木兔,当前气候条件下适宜生境面积为210031.3 km 2,主要分布在巴州、阿克苏地区、喀什地区东北部、和田地区西北部和东部。RCP 4.5气候情境下的2050年代和2070年代适宜生境面积分别缩小2.35%和扩大2.96%;RCP 8.5气候情境下的2个年代适宜生境面积分别缩小0.01%和扩大6.3%。对于草兔,当前气候条件下适宜生境面积为228981.3 km 2,主要分布在阿勒泰地区、塔城地区北部、伊宁县、沙湾县、克拉玛依、哈密市北部、南疆的乌恰县和塔西库尔干县;RCP 4.5气候情境下适宜生境面积缩小4.27%和5.37%;RCP 8.5气候情境下适宜生境面积缩小7.22%和5.97%;对于雪兔,当前气候条件下适宜生境面积为112269 km 2,主要分布在阿勒泰地区中北部、塔城地区北部、博州西部,伊宁县、尼勒克县等地区;RCP 4.5气候情境下适宜生境面积缩小5.68%和6.23%;RCP8.5气候情境下适宜生境面积缩小4.66%和4.21%。根据研究分析认为伴随着气候的变化新疆兔属3个物种潜在生境面积都出现不同程度的减小趋势,建议采取适应气候变化的保护措施。

Climate change is one of the major factors contributing to biodiversity decline and habitat loss.It is therefore important to study the impacts of climate change on biodiversity decline and habitat loss,and plan accordingly to protect species diversity and maintain ecosystem functional integrity.We studied three species,viz Lepus yarkandensis,Lepus capensis and Lepus timidus,in Xinjiang,China and analyzed 10 environmental factors as potential agents of habitat distribution.We used the MaxEnt model to assess current conditions and future 2041-2060(2050s)and 2061-2080(2070s)RCP 4.5 and RCP 8.5 climate scenarios,to identify key factors affecting habitat distribution.The accuracy of the model in predicting the habitat distribution of our three species reached a high level.The AUC values for L.yarkandensis,L.capensis and L.timidus were 0.955,0.853 and 0.940,respectively.According to the importance of environmental variables quantified by by Jackknife test,the main environmental variables affecting the habitat distribution of L.yarkandensis were average temperature in the coldest season,average annual rainfall,slope,average temperature in the driest season.For L.capensis the key factors were the driest monthly rainfall,isotherm,annual average rainfall,monthly mean of diurnal temperature difference.For L.timidus key factors were the driest month rainfall,isotherm,and the monthly mean of diurnal temperature difference.For L.yarkandensis,the suitable habitat area was 210031.3 km 2 under current climate conditions.The suitable habitat area was mainly distributed in Bazhou,Aksu,northeast of Kashgar and northwest of Hetian.In the RCP 4.5 climate scenario,the suitable habitat area decreased by 2.35%for the 2050s and increased by 2.96%for the 2070s.In the RCP 8.5 climate scenario,the suitable habitat area was stable and increased by 6.3%,respectively.For L.capensis,the suitable habitat area was 228981.3 km 2 under current climate conditions.The suitable habitat area was mainly distributed in Altay,northern Tacheng,Yining,Shawan,Karamay,northern Hami,Wuqia and TaxiKurgan counties in southern Xinjiang.Suitable habitat area decreased by 4.27%and 5.37%under the RCP 4.5 climate scenario,and by 7.22%and 5.97%under the RCP 8.5 climate scenario.For L.timidus,the suitable habitat area was 112269 km 2 under current climate conditions.Suitable habitats were mainly distributed in the north-central Altay,northern Tacheng,western Bozhou,Yining County,Nileke County and other areas.Suitable habitat area decreased by 5.68%and 6.23%under the RCP 4.5 climate scenario,and by 4.66%and 4.21%under the RCP 8.5 climate scenario.Generally speaking,with climate change,the potential habitat area of these three species of Lepus in Xinjiang showed a decreasing trend to varying degrees.We recommend adoption of measures to reduce impacts of climate change.