【摘要】 明确濒危物种的微生境选择特征是为其制定科学保护策略的基础。鳄蜥(Shinisaurus crocodilurus)是全球濒危物种,野外种群数量仅剩1,500只左右。本研究于广东罗坑鳄蜥国家级自然保护区,针对鳄蜥集中分布的溪沟开展微生境样方调查,系统分析了鳄蜥的微生境选择特征。随机森林模型分析以及袋外误差计算表明栖枝密度、溪流深度、溪流沙覆盖比、郁闭度、溪流流速和溪流宽度是影响鳄蜥利用微生境的重要变量,并具有特定的生态阈值。广义线性混合效应最终模型表明,栖枝密度、溪流深度、郁闭度和溪流宽度与鳄蜥出现概率呈显著正相关;其中,栖枝密度为影响鳄蜥出现概率的首要因子,溪流深度次之;郁闭度虽独立贡献率较低,然其作用不可或缺,是基础性影响因子;而溪流宽度则为边缘影响因子。多模型分析结果综合表明,鳄蜥尤其偏好高栖枝密度的微生境,可能与其获取庇护和食物资源的需求相关。研究建议,在鳄蜥保护中应以提高栖枝密度构建多层次庇护网络作为首要目标,同时通过改善水文环境和提高乔木郁闭度等措施,为鳄蜥种群提供更适宜的生存环境。更多还原

【Abstract】 Aim: Identifying the microhabitat selection characteristics of endangered species is essential for developing effective conservation strategies. The Chinese crocodile lizard(Shinisaurus crocodilurus) is a globally endangered species, with fewer than 1,500 individuals remaining in the wild. This study aimed to systematically analyze the influence of various microhabitat variables on the microhabitat selection of Chinese crocodile lizards. Methods: We carried out microhabitat quadrat investigations in the stream environments where Chinese crocodile lizards are distributed within the Guangdong Luokeng Crocodile Lizard National Nature Reserve. We used random forest model and generalized linear mixed model(GLMM) to assess the key microhabitat variables that determined the occurrence of Chinese crocodile lizards. Results: Random forest analysis revealed that perch density, stream depth, stream sand coverage percentage, canopy closure, stream velocity, and stream width were the critical microhabitat variables affecting the occurrence of Chinese crocodile lizards, each with specific ecological thresholds. The final GLMM indicated that perch density, stream depth, canopy closure, and stream width all exhibited significant positive associations with the occurrence probability of the Chinese crocodile lizard. Among these variables, perch density was identified as the primary influencing factor, followed by stream depth. Despite its modest independent contribution, canopy closure served as an indispensable underlying factor, whereas stream width was determined to be a marginal factor, exerting a limited effect. Conclusion: Our study highlights that improving perch density should be prioritized in the conservation of Chinese crocodile lizards. Simultaneously, measures such as improving the hydrological environment and optimizing canopy closure should be implemented to provide more suitable microhabitats for the population. These findings contribute to a better understanding of the microhabitat requirements of Chinese crocodile lizards and provide scientific basis for targeted conservation actions.更多还原