Limits to species distributions on tropical mountains shift from high temperature to competition as elevation increases
Limits to species distributions on tropical mountains shift from high temperature to competition as elevation increases
复制标题
随着海拔的增加，热带山区物种分布的限制从高温转向竞争
DOI：
10.1002/ecm.1597
复制
发表时间：
2023
影响因子：
6.1
通讯作者：
Chen J
中科院分区：
文献类型：
--
作者：
Chen J
随着海拔的升高物种更替是一种普遍现象，并提供了关于生态群落为什么以及如何随着气候变暖而重组的有价值的信息。人们通常认为，物种的相互作用更有可能设定温暖的范围限制，而生理耐受性决定冷的范围限制。然而，大多数研究都是从温带系统，并依赖于热生理性状和范围限制之间的相关性，很少有人知道生理性状和生物相互作用如何同时改变沿着连续的温度梯度。我们使用了相关性和实验方法相结合，调查社区ofDrosophilaflies在热带雨林的澳大利亚湿，那里有大量的物种营业额与海拔。我们的实验量化了个体水平和种群水平对温度的反应，以及不同温度制度下种间竞争的影响。物种的分布更好地解释了他们在极端温度下的表现比他们的热最佳。温度上限在物种间的变化小于温度下限。尽管如此，这些小的差异与分布中心海拔的差异有关。低海拔物种并不是对寒冷耐受性最低的物种，这表明寒冷的温度并没有限制它们在高海拔地区的丰度。相反，在高地温度制度下，这些低海拔物种的丰度减少了与高海拔物种的竞争，在短期和长期的竞争实验。我们的研究结果表明，高海拔物种被低海拔地区的高温限制在它们目前的活动范围内，这表明它们的活动范围对未来的变暖高度敏感。与预期相反，物种间的相互作用强烈影响了凉爽，高海拔地区的群落组成。总之，这些结果提高了热带群落与更好研究的温带群落在生物相互作用和非生物因素在塑造群落组成方面的相对重要性以及这些因素的影响如何随着温度的升高而变化方面的可能性。
Species turnover with elevation is a widespread phenomenon and provides valuable information on why and how ecological communities might reorganize as the climate warms. It is commonly assumed that species interactions are more likely to set warm range limits, while physiological tolerances determine cold range limits. However, most studies are from temperate systems and rely on correlations between thermal physiological traits and range limits; little is known about how physiological traits and biotic interactions change simultaneously along continuous thermal gradients. We used a combination of correlational and experimental approaches to investigate communities ofDrosophilaflies in rainforests of the Australian Wet Tropics, where there is substantial species turnover with elevation. Our experiments quantified individual‐level and population‐level responses to temperature, as well as the impact of interspecific competition under different temperature regimes. Species' distributions were better explained by their performance at extreme temperatures than by their thermal optima. Upper thermal limits varied less among species than lower thermal limits. Nonetheless, these small differences were associated with differences in the centered elevation of distribution. Low‐elevation species were not those with the lowest tolerance to cold, suggesting that cold temperatures were not limiting their abundance at high elevations. Instead, under upland temperature regimes, abundances of these low‐elevation species were reduced by competition with a high‐elevation species, in both short‐ and long‐term competition experiments. Our results demonstrate that high‐elevation species are confined to their current ranges by high temperatures at lower elevations, indicating that their ranges will be highly sensitive to future warming. Counter to expectation, species interactions strongly influenced community composition at cooler, high‐elevation sites. Together, these results raise the possibility that tropical communities differ from better‐studied temperate communities in terms of the relative importance of biotic interactions and abiotic factors in shaping community composition and how the impact of these factors will change as temperatures increase.