Climate drives loss of phylogenetic diversity in a grassland community
Climate drives loss of phylogenetic diversity in a grassland community
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DOI：
10.1073/pnas.1912247116
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
Daijiang Li;Jesse E. D. Miller;S. Harrison
中科院分区：
文献类型：
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作者：
Daijiang Li;Jesse E. D. Miller;S. Harrison
显著性模型预测，干燥的气候可能会减少生态群落中包含的进化历史的数量（即，系统发育多样性），但仍缺乏明确的经验证据。我们报告了干旱引起的草原植物群落系统发育多样性的侵蚀。在一个较长的时期比正常的生长季节干燥，许多物种，特别是那些不耐旱的功能特性，失去了社区和系统发育多样性的下降。我们的研究代表了气候引起的多样性丧失可能超出物种水平的首批证据之一。然而，我们的研究也表明了物理和生物复杂景观作为在不断变化的世界中保持生物多样性的避难所的积极价值。虽然气候变化已经通过局部排斥、范围转移和改变相互作用深刻地影响了生物多样性，但它对共存物种或系统发育群落多样性的进化历史的影响还有待记录。系统发育群落多样性可能是功能策略多样性的一个代表，这些策略可以帮助维持生态系统在面临干扰时的稳定性。在气候变暖的情况下，系统发育多样性可能特别容易受到温暖、水有限地区植物群落减少的影响，因为缺水加剧消除了不耐旱的物种，这些物种可能是过去潮湿气候的遗迹，可能与共存物种有远亲关系。在这里，我们记录了一个19年的草原群落的系统发育多样性下降的水分变得不那么丰富，可预测的一年中的一个关键时刻。这种下降是最强烈的本地杂类草，特别是那些具有高比叶面积，干旱敏感性的特点，表明。这种下降发生在小的空间尺度上，物种相互作用，但较大的区域社区迄今已缓冲其高水平的物理和生物异质性的系统发育多样性的损失。
Significance Models have predicted that drier climates could reduce the amount of evolutionary history contained within ecological communities (i.e., phylogenetic diversity), but clear empirical evidence is still lacking. We report a drought-induced erosion of the phylogenetic diversity of grassland plant communities. During a long period of drier than normal growing seasons, many species, especially those with drought-intolerant functional traits, were lost from communities and contributed to the declines in phylogenetic diversity. Our study represents one of the first demonstrations that climate-induced loss of diversity may extend beyond the level of the species. However, our study also indicates the positive value of physically and biologically complex landscapes as refuges for maintaining biodiversity in a changing world. While climate change has already profoundly influenced biodiversity through local extinctions, range shifts, and altered interactions, its effects on the evolutionary history contained within sets of coexisting species—or phylogenetic community diversity—have yet to be documented. Phylogenetic community diversity may be a proxy for the diversity of functional strategies that can help sustain ecological systems in the face of disturbances. Under climatic warming, phylogenetic diversity may be especially vulnerable to decline in plant communities in warm, water-limited regions, as intensified water stress eliminates drought-intolerant species that may be relicts of past wetter climates and may be distantly related to coexisting species. Here, we document a 19-y decline of phylogenetic diversity in a grassland community as moisture became less abundant and predictable at a critical time of the year. This decline was strongest in native forbs, particularly those with high specific leaf area, a trait indicating drought sensitivity. This decline occurred at the small spatial scale where species interact, but the larger regional community has so far been buffered against loss of phylogenetic diversity by its high levels of physical and biotic heterogeneity.