Department of Environmental Science and Policy, University of California, Davis, CA 95616;
Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521.
Proc Natl Acad Sci U S A. 2020 Mar 3;117(9):4464-4470. doi: 10.1073/pnas.1921724117. Epub 2020 Feb 18.
Climate strongly shapes plant diversity over large spatial scales, with relatively warm and wet (benign, productive) regions supporting greater numbers of species. Unresolved aspects of this relationship include what causes it, whether it permeates to community diversity at smaller spatial scales, whether it is accompanied by patterns in functional and phylogenetic diversity as some hypotheses predict, and whether it is paralleled by climate-driven changes in diversity over time. Here, studies of Californian plants are reviewed and new analyses are conducted to synthesize climate-diversity relationships in space and time. Across spatial scales and organizational levels, plant diversity is maximized in more productive (wetter) climates, and these consistent spatial relationships are mirrored in losses of taxonomic, functional, and phylogenetic diversity over time during a recent climatic drying trend. These results support the tolerance and climatic niche conservatism hypotheses for climate-diversity relationships, and suggest there is some predictability to future changes in diversity in water-limited climates.
气候在较大的空间尺度上强烈影响植物多样性，相对温暖和湿润（有利的、多产的）地区支持更多的物种。这种关系尚未解决的方面包括它是由什么引起的，它是否渗透到较小空间尺度的群落多样性中，它是否伴随着功能和系统发育多样性的模式，正如一些假设所预测的那样，以及它是否与随着时间的推移多样性的气候驱动变化相平行。在这里，回顾了加利福尼亚植物的研究，并进行了新的分析，以综合空间和时间上的气候多样性关系。在空间尺度和组织水平上，植物多样性在生产力更高（更湿润）的气候中达到最大值，这些一致的空间关系反映在随着最近气候干燥趋势的时间推移，分类学、功能和系统发育多样性的丧失上。这些结果支持了气候多样性关系的耐受性和气候生态位保守性假说，并表明在水资源有限的气候中，未来多样性的变化具有一定的可预测性。
