Université Pierre et Marie Curie - Paris 6, UMR 7618 BIOEMCO, Ecole Normale Supérieure, 46 rue d'Ulm, 75230, Paris Cedex 05, France.
Glob Chang Biol. 2013 Oct;19(10):3062-8. doi: 10.1111/gcb.12299. Epub 2013 Jul 31.
The unprecedented rate of global warming requires a better understanding of how ecosystems will respond. Organisms often have smaller body sizes under warmer climates (Bergmann's rule and the temperature-size rule), and body size is a major determinant of life histories, demography, population size, nutrient turnover rate, and food-web structure. Therefore, by altering body sizes in whole communities, current warming can potentially disrupt ecosystem function and services. However, the underlying drivers of warming-induced body downsizing remain far from clear. Here, we show that thermal clines in body size are predicted from universal laws of ecology and metabolism, so that size-dependent selection from competition (both intra and interspecific) and predation favors smaller individuals under warmer conditions. We validate this prediction using 4.1 × 10(6) individual body size measurements from French river fish spanning 29 years and 52 species. Our results suggest that warming-induced body downsizing is an emergent property of size-structured food webs, and highlight the need to consider trophic interactions when predicting biosphere reorganizations under global warming.
全球变暖的速度前所未有，这要求我们更好地了解生态系统将如何做出反应。在温暖的气候下，生物体的体型通常较小（伯格曼法则和温度-体型法则），而体型是决定生物史、人口统计学、种群大小、营养周转率和食物网结构的主要因素。因此，当前的变暖可能会破坏生态系统的功能和服务，因为它改变了整个群落的体型。然而，变暖导致体型缩小的潜在驱动因素还远不清楚。在这里，我们表明，体型的热梯度可以从生态学和新陈代谢的普遍规律中预测出来，因此，竞争（包括种内和种间竞争）和捕食导致的体型依赖性选择有利于在温暖条件下体型较小的个体。我们使用来自法国河流鱼类的 410 万个体型测量数据（跨越 29 年和 52 个物种）验证了这一预测。我们的研究结果表明，变暖引起的体型缩小是体型结构食物网的一个新兴特性，并强调在预测全球变暖下的生物圈重组时需要考虑营养相互作用。
