Data from: Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus

Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.生境破碎化可显著影响种群遗传结构，并降低小型孤立种群的遗传多样性与生存力。白头叶猴（Trachypithecus leucocephalus）是一种极度濒危的灵长类物种，栖息于中国南部高度破碎化且受人类活动干扰的生境中。本研究针对该物种的种群遗传结构与遗传多样性展开调查，并解析可能塑造其种群结构的环境与人为干扰因子。我们采集了白头叶猴主要分布区内41个社会群体的214份独特多位点基因型数据，结果显示当地种群间存在强烈的遗传结构与显著的遗传分化。本研究采用因果建模框架开展景观遗传学分析，结果表明：大型生境缺口与地理距离是塑造种群遗传结构的核心景观因子；但即便被小型生境缺口或道路分隔的林斑块之间，也存在高水平的遗传分化。本研究是首个利用核标记评估白头叶猴种群遗传结构与多样性的综合性研究。研究结果证实，人类土地开发活动与生境破碎化对灵长类林斑块间的遗传连通性具有强烈的负面影响。本研究分析结果表明，该物种可划分为2个管理单元，同时提示应强化并恢复生境连通性，以降低遗传隔离程度，提升种群生存力。