Climate and competition combine to set elevational distributions of tropical rainforest Drosophila
Climate and competition combine to set elevational distributions of tropical rainforest Drosophila
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气候和竞争共同决定了热带雨林果蝇的海拔分布
DOI：
10.1101/2022.04.01.486700
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发表时间：
2022
期刊：
影响因子：
--
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。热带山地具有明显的温度梯度和强烈的物种相互作用，是研究生物耐热性与物种相互作用关系的试验场，是影响物种分布的直接因素。我们调查了温度和种间竞争的原因，物种周转和丰富的九种ofDrosophila沿海拔梯度在澳大利亚湿热带地区的变化。热性能曲线表明，物种的分布更好地解释了他们在极端温度下的性能，而不是他们的热最佳。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的中心海拔的差异，在低海拔地区的社区组成的驱动程序与环境排序一致。与此相反，在凉爽，高海拔的社区组成是由温度依赖的种间竞争，而不是耐低温。这些结果违背了关于非生物和生物因素在沿着温度梯度构建群落中的作用的常见假设，并表明热带昆虫可能非常容易受到未来变暖的影响。我们的研究说明了实验的重要性，跨生物水平的定量测试（即，个体到群体）和时间尺度（即，代内到多代），以表征气候对密切相互作用物种的行业协会的影响。
Species turnover with elevation is a widespread phenomenon and provides valuable information on why and how ecological communities might reorganize as the climate warms. Tropical mountains typically have pronounced thermal gradients and intense species interactions, providing a testing ground for investigating the relationship between thermal tolerances and biotic interactions as the proximate factors influencing species’ distributions. We investigated temperature and interspecific competition as causes of species turnover and abundance changes of the nine most abundant species ofDrosophilaalong elevational gradients in the Australian Wet Tropics. Thermal performance curves revealed that species’ distributions were better explained by their performance at extreme temperatures, rather than their thermal optima. Upper thermal limits varied less among species than lower thermal limits. Nonetheless, these small differences were associated with differences in centred elevation of distribution, consistent with environmental sorting as a driver of community composition at low-elevation sites. In contrast, community composition at cool, high elevations was driven by temperature-dependent interspecific competition rather than tolerance to low temperatures. These results run counter to common assumptions about the role of abiotic and biotic factors in structuring communities along thermal gradients, and indicate that tropical insects may be highly vulnerable to future warming. Our study illustrates the importance of experimental, quantitative tests across biological levels (i.e., individuals to populations) and temporal scales (i.e., within-generation to multi-generation) for characterizing effects of climate on a guild of closely-interacting species.