濒危物种局域种群划分技术与应用——以大熊猫为例

Habitat degradation and fragmentation are the main threat to the world's endangered species. The theory of metapopulation has been proved to be critical to the modern practice of wildlife conservation and management. Most of the endangered terrestrial animal in China are under the threat of habitat fragmentation, and thus the management on their local population become a key priority. The identification of local population in practical conservation, however, is difficult, even for successful protected species like giant panda (Ailuropoda melanoleuca). This study aims to to develop a method of practical and scientific interest to identify the local population of endangered species, with the case of giant panda. The habitat patches of will be discriminate with from the space data of environmental and ecological factors such as land cover, climate, topography and human disturbance, so will the resistance in landscape. Genetic distance between groups of giant panda will be evaluated using the data of microsatellites. Applying the theory of isolation by resistance, we will evaluate the isolation index between all groups of giant panda by calibrating the landscape resistance with genetic distance. The local population will be identified according to the isolation index. The threshold for determining local population will be chosen based on the special distribution of giant panda individual. This study can provide critical technical support to the conservation management for those endangered terrestrial species under the threat of habitat fragmentations.

全球范围内，濒危物种的栖息地正面临面积萎缩、斑块化严重和隔离程度增加的问题。我国大量濒危动物也面临栖息地破碎化的威胁和随之而来的局域物种保护问题。集合种群理论在野生动物保护管理中发挥着重要的指导作用。但实践工作中，包括大熊猫(Ailuropoda melanoleuca)在内的濒危动物的局域种群划分却很困难。本研究拟以大熊猫为例，兼顾科学性和实用性，整合景观和种群遗传学方法，建立一套濒危物种局域种群的划分方法。首先基于植被、气候、地形、人类干扰等生态环境因子确定栖息地斑块，然后计算斑块之间的景观隔离指数，再基于IBR（Isolation by resistance）理论，用各斑块群体之间的遗传距离标定景观隔离指数。在此基础上，结合物种空间分布格局，确定隔离指数阈值，划分局域种群。本研究将为受栖息地破碎化威胁的濒危陆生野生动物的保护管理工作提供关键的技术支持。

对大量濒危物种的保护管理依赖于物种的种下单元，尤其是局域种群的管理。局域种群的识别是濒危物种保护管理政策实施的前提，但是却非常困难。本项目以大熊猫(Ailuropoda melanoleuca)为例，基于大熊猫分布位点和栖息地环境因子，通过聚合模型分析，对四川大熊猫栖息地质量（HSI）进行了评估，确定了所有大熊猫分布点之间的景观隔离状况。利用大熊猫个体的微卫星遗传信息，计算了大熊猫个体的种群遗传距离，确定了遗传距离和景观距离的相关关系。在此基础上，基于图论研发了局域种群空间边界的划分方法，该方法与四川五大山系现有大熊猫保护地网络有一定的吻合性。基于本项目结果，还评估了道路和人类活动对大熊猫种群分布和栖息地的影响，以及现有保护地网络存在的问题。这一研究对濒危物种保护地的规划、局域种群隔离的生态恢复、种群复壮管理（比如放归）有重要意义。