Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany.
College of African Wildlife Management, Moshi, Tanzania.
J Anim Ecol. 2019 Dec;88(12):1860-1872. doi: 10.1111/1365-2656.13074. Epub 2019 Aug 13.
Despite their diversity and their large functional and cultural importance, the patterns and predictors of large mammal diversity along elevational gradients on tropical mountains remain poorly understood. Today, large mammals are threatened by human disturbances such as habitat destruction and hunting and may increasingly depend on the conservation of protected areas. Here, we use field data on the diversity of large mammals along a 3.6 km elevational gradient on Mt. Kilimanjaro to evaluate the importance of climate, net primary productivity and human impact for the distribution, species richness and community biomass of wild mammals. Mammal species richness was explored with camera traps on 66 study plots along an elevational gradient from 870 to 4,550 m a.s.l.. We applied path analysis and variance partitioning analysis to unravel the direct and indirect effects of temperature, precipitation, primary productivity, land use, land area, the protection of habitats and the occurrence of domestic mammals on the diversity of wild mammals. Both species richness and community biomass of wild mammals showed a unimodal distribution with elevation, peaking in the montane zone of Mt. Kilimanjaro. However, the peak shifted significantly to lower elevations when only protected habitats were considered. Wild mammal diversity increased with net primary productivity, protection of habitats and temperature. Our study underscores the importance of energy resources for the establishment of diversity gradients in large mammals. While temperature has been revealed as a direct predictor of diversity in most ectothermic taxa, in endothermic organisms temperature has stronger indirect effects, via a modulation of net primary productivity. Moreover, our study reveals how patterns of diversity on tropical mountains are influenced by human impact, pointing to the pivotal role of protected areas for the long-term conservation of mountain biodiversity.
尽管大型哺乳动物种类繁多，具有重要的功能和文化意义，但它们沿热带山地海拔梯度的多样性模式和预测因素仍知之甚少。如今，大型哺乳动物受到人类干扰的威胁，如栖息地破坏和狩猎，它们可能越来越依赖保护区的保护。在这里，我们利用在乞力马扎罗山海拔 3.6 公里梯度上采集的大型哺乳动物多样性的实地数据，评估气候、净初级生产力和人类活动对野生动物分布、物种丰富度和群落生物量的重要性。我们在 66 个研究点上使用相机陷阱来研究哺乳动物的物种丰富度，这些研究点沿海拔梯度从 870 米到 4550 米不等。我们应用路径分析和方差分解分析来揭示温度、降水、初级生产力、土地利用、土地面积、栖息地保护和家养哺乳动物的发生对野生动物多样性的直接和间接影响。野生动物的物种丰富度和群落生物量都呈现出单峰分布，随着海拔的升高而增加，在乞力马扎罗山的山地带达到峰值。然而，当只考虑受保护的栖息地时，峰值显著向较低的海拔移动。野生动物多样性随着净初级生产力、栖息地保护和温度的增加而增加。我们的研究强调了能量资源对大型哺乳动物多样性梯度建立的重要性。虽然温度已被揭示为大多数外温动物类群多样性的直接预测因子，但在恒温动物中，温度通过调节净初级生产力，具有更强的间接影响。此外，我们的研究揭示了热带山脉多样性模式如何受到人类活动的影响，指出保护区对山区生物多样性的长期保护起着关键作用。
