气候变化对中国大黄花虾脊兰及其传粉者适生区的影响

大黄花虾脊兰(Calanthe sieboldii)是典型的大陆与岛屿间间断分布的兰科物种, 适宜分布气候范围狭窄, 同时依赖特殊的传粉者传粉, 包括黄胸木蜂(Xylocopa appendiculata)、赤足木蜂(X. rufipes)和中华绒木蜂(X. chinensis)等3种木蜂属(Xylocopa)昆虫。本文通过R语言Biomod2程序包建立物种分布模型(SDM), 预测了2050年和2070年时大黄花虾脊兰及其传粉者在3种代表浓度路径(RCP2.6、RCP4.5与RCP8.5)下的分布格局, 以期为该濒危植物的保育提供参考。结果表明: 降水相关变量比温度相关变量对大黄花虾脊兰分布的平均解释率更高, 两者分别为25.4%和13.9%。当前大黄花虾脊兰适生区主要集中在华中和华东地区, 未来适生区的增减主要受到气候情景的影响, 其变化范围为-59.0%到34.7%, 并可能向更高海拔的地区移动; 未来木蜂适生区将净收缩16.4%-19.7%, 且主要向西北和东北移动; 因而两者共同分布的面积占大黄花虾脊兰适生区的比例未来相比当前的90.0%可能下降0.5%-11.4%, 表明大黄花虾脊兰分布可能受到未来气候变化和传粉者分布减少的双重影响, 因此对该物种或类似特化传粉的兰科植物进行保育时应当充分考虑传粉者因素。

Influence of the climate change on suitable areas of Calanthe sieboldii and its pollinators in China

Calanthe sieboldii is an orchid species with a narrow range of suitable habitats that are typically disjunction between continents and islands. Calanthe sieboldii relies on specific pollinators such as Xylocopa carpenter bees, including X. appendiculata, X. rufipes and X. chinensis. This study built a species distribution model (SDM) using the Biomod2 package of R to predict the distribution patterns of C. sieboldii and Xylocopa spp. in China under three different representative concentration pathways in 2050 and 2070. The results show the distribution of C. sieboldii is better explained by precipitation-related variables than temperature-related variables, 25.4% and 13.9%, respectively. The current suitable habitats for C. sieboldii are mainly in Central China and East China. However, future climate change scenarios may shift these habitats, which will shift to higher altitude area, and may change -59.0% to 34.7% dominated by future climate change scenarios. The range of suitable areas for Xylocopa spp. will decrease by 16.4%-19.7%, moving to Northwest and Northeast China. Consequently, as the co-distribution areas between plant and pollinators account for suitable areas C. sieboldii, the orchid’s distribution will decrease by 0.5%-11.4% from 90.0%, indicating that the distribution of C. sieboldii will suffer from future climate change and declining pollinators. Therefore, the pollinator should be considered carefully in the conservation of C. sieboldii or similar specialized-pollination orchid species.