气候变化对邛崃山系大熊猫主食竹和栖息地分布的影响

气候变化对生物多样性的影响,特别是珍稀濒危物种的影响是当前的研究热点。全球气候变化对大熊猫的影响一直受到广泛关注。根据野外调查的大熊猫活动痕迹点、竹类分布点和主食竹扩散距离数据,采用Maxent模型,利用植被、地形、气候等因素,在RCP8.5下分析了2050年和2070年邛崃山系大熊猫主食竹分布及栖息地变化趋势。结果显示:(1)未来大熊猫适宜生境及主食竹气候适宜区面积均有所减少,到2070年分别减少37.2%和4.7%;(2)未来主食竹分布范围总体向高海拔扩展,但面积持续减少,到2070年分布面积比当前减少8.3%;(3)大熊猫栖息地未来有向高海拔扩张的趋势,在低海拔地区退缩明显,到2070年较当前减少27.2%;但到2070年大熊猫栖息地面积加上非栖息地有主食竹分布的面积,较现有大熊猫栖息地面积大1.5%;(4)受气候变化影响较严重的区域是邛崃山系南部以及低海拔地区,其余区域所受影响相对较小;(5)未来需要加强对受气候变化影响严重区域的监测与保护,特别是邛崃山系中部的大熊猫集中分布区。

Climate-change impacts on bamboo distribution and giant panda habitat in Qionglai mountains

The effects of climate change on biodiversity are at the forefront of contemporary scientific research, especially regarding rare and endangered species. As an old, highly specialized and extremely rare species, the effect of global climate change on the giant panda(Ailuropoda melanoleuca) has received much attention. Due to climate change, giant panda habitats are generally becoming warmer and drier, reducing the total suitable area thereby giant pandas are migrating to higher latitudes and altitudes. Climate change not only directly affect species distribution, but also indirectly alters the size and distribution of herbivore populations by influencing the growth of staple food plants. Bamboo comprises > 99% of the giant panda''s diet. This strong dependence couples the distribution of the giant panda with that of bamboo growth. Based on current locality and distributional data of giant pandas and bamboo species, respectively, from field surveys, we predicted distributional shifts of bamboo and giant panda habitats for the years 2050 and 2070 using a Maxent model with topography factors (altitude, slope and aspect), climate change data, river, road, resident community and land cover. We obtained current and future climate projections (for the years 2050 and 2070) from the WorldClim database at 30'' resolution. The model was constrained by the conditions outlined in the representative concentration pathway 8.5 of the IPCC AR5. We assessed the accuracy of predictions of the area under the ROC curve (AUC), establishing the acceptable predictions of Maxent. The results show that the climatically suitable areas of bamboo and habitat for giant pandas might decrease by 4.7% and 37.2% in 2070, respectively. The northern and lower elevation limits of current suitable habitat for giant pandas would decrease, whereas suitable habitat would primarily expand to higher elevations. Lower elevations of climatically suitable areas of bamboo would also decrease; however the distribution of bamboo would primarily expand to higher elevations. Therefore the area of giant panda habitat will decrease by 27.2% and giant pandas would move to higher altitudes. Although bamboo will spread to higher elevations, and the total proportion of bamboo distribution will decrease by 8.3% in 2070, there will be sufficient food resources for nearly all giant pandas in this region. This suggests that climate change has limited impacts on giant pandas in the Qionglai Mountains. The southern area of the Qionglai Mountains and low-altitude regions are more sensitive to climate change, which may require additional management, research, and conservation in the future. The main habitats of giant panda (Wenchuan, Baoxing, Lushan, Dayi, Chongzhou and Tianquan counties)will also required additional focus in future studies.