Abstract Distribution of biodiversity along the elevation gradient have been a subject of curiosity and a much argued topic in macroecology. Despite considerable attention, there is a lack of consensus on the pattern and the causal factors across regions and taxa. We studied amphibian distribution along the elevational gradient in Sikkim, Eastern Himalaya, part of a globally significant biodiversity hotspot. We conducted intensive field studies covering 300–4600 m elevation using Visual Encounter Survey and Night Stream Survey methods. We examined the effects of both spatial factors (area and mid-domain effect) and environmental variables (temperature, precipitation, moisture, potential evapotranspiration and actual evapotranspiration) on the distribution of amphibians along the elevational gradient. We recorded 25 species and 1368 individuals of amphibians after 1236 man-hours of visual encounter survey and 27 km night stream survey. Species richness of total amphibians and their sub groups (endemic, non-endemic, large-range and small-range) followed unimodal pattern showing a peak at middle elevation but with slight shift towards higher elevation for endemic species. Various environmental variables, especially actual evapotranspiration and mean annual precipitation, explained the elevational distribution trend of amphibians in the Eastern Himalaya. Spatial factors played no significant role in shaping the pattern of amphibian distribution (except endemics and large-range species showing fit to mid-domain effect). Local communities of the study area extract amphibians for food and medicine, especially from the diverse mid elevation zone, which should be closely monitored and curbed by the wildlife authorities.

中文翻译：

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印度喜马拉雅东部沿海拔梯度分布的两栖动物

摘要 生物多样性沿海拔梯度分布一直是宏观生态学中一个令人好奇和争论不休的话题。尽管受到了相当多的关注，但对跨区域和分类群的模式和因果因素缺乏共识。我们研究了喜马拉雅东部锡金沿海拔梯度分布的两栖动物，该地区是全球重要的生物多样性热点的一部分。我们使用视觉遭遇调查和夜流调查方法进行了覆盖 300-4600 米高程的密集实地研究。我们研究了空间因素（面积和中域效应）和环境变量（温度、降水、湿度、潜在蒸散量和实际蒸散量）对两栖动物沿海拔梯度分布的影响。经过 1236 个工时的视觉遭遇调查和 27 公里的夜间河流调查，我们记录了 25 个物种和 1368 个两栖动物个体。两栖动物总数及其亚群（地方性、非地方性、大范围和小范围）的物种丰富度遵循单峰模式，显示在中等海拔处达到峰值，但地方性物种略微向高海拔移动。各种环境变量，特别是实际蒸散量和年平均降水量，解释了喜马拉雅东部两栖动物的海拔分布趋势。空间因素在塑造两栖动物分布模式方面没有发挥重要作用（地方性和大范围物种除外，显示出适合中域效应）。研究区的当地社区提取两栖动物作为食物和药物，特别是从多样化的中海拔地区，