Niche Conservatism Drives Elevational Diversity Patterns in Appalachian Salamanders
Niche Conservatism Drives Elevational Diversity Patterns in Appalachian Salamanders
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DOI：
10.1086/653031
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发表时间：
2010-07-01
影响因子：
2.9
通讯作者：
Wiens, John J.
中科院分区：
文献类型：
--
作者：
Kozak, Kenneth H.;Wiens, John J.
许多生物多样性热点位于山地地区，许多动植物种群在中等海拔地区的物种丰富度最高。然而，这种驼峰形状的多样性格局的解释仍然不清楚，因为还没有研究同时解决生态和进化原因。在这里，我们使用近乎全面的系统发育和环境数据，解决了北美多齿类火蜥蜴的这些原因。我们开发了一个零模型来评估一个地区被占领的时间与其物种丰富度之间的关系，并应用了一种新的方法来测试分支是否在其气候生态位(生态位保守主义)中表现出长期停滞。在进化上，物种丰富度的中海拔高峰可以用物种形成时间效应来解释，中等海拔生境似乎居住时间最长，积累了更多的物种。我们发现，这种模式与物种气候生态位的进化停滞有关，通过限制谱系向低海拔和高海拔环境的扩散来驱动中海拔高峰。这些过程可能有助于解释世界各地许多山地地区的海拔多样性模式。结果还表明，山地生物群可能同时具有高度的物种多样性和系统发育多样性，但可能特别容易受到快速气候变化的影响。
Many biodiversity hotspots are in montane regions, and many plant and animal groups have their highest species richness at intermediate elevations. Yet, the explanation for this hump-shaped diversity pattern has remained unclear because no studies have addressed both the ecological and evolutionary causes. Here, we address these causes in North American plethodontid salamanders, using a near-comprehensive phylogeny and environmental data. We develop a null model for assessing the relationship between the time that an area has been occupied and its species richness, and we apply a new approach that tests whether clades exhibit long-term stasis in their climatic niches (niche conservatism). Evolutionarily, the midelevation peak in species richness is explained by the time-for-speciation effect, with intermediate-elevation habitats seemingly being inhabited longest and accumulating more species. We find that this pattern is associated with evolutionary stasis in species' climatic niches, driving the midelevation peak by constraining the dispersal of lineages to environments at lower and higher elevations. These processes may help explain elevational diversity patterns in many montane regions around the world. The results also suggest that montane biotas may harbor high levels of both species diversity and phylogenetic diversity but may be particularly susceptible to rapid climate change.