Global change effects on plant communities are magnified by time and the number of global change factors imposed
Global change effects on plant communities are magnified by time and the number of global change factors imposed
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DOI：
10.1073/pnas.1819027116
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发表时间：
2019-09-03
影响因子：
11.1
通讯作者：
Zhang, Yunhai
中科院分区：
文献类型：
--
作者：
Komatsu, Kimberly J.;Avolio, Meghan L.;Zhang, Yunhai
全球变化驱动因素(GCDS)预计将改变社区结构，从而改变生态系统提供的服务。然而，很少有实验研究考察GCDS对多种生态系统类型植物群落结构的影响，而那些确实存在的研究呈现出相互矛盾的模式。在一项史无前例的对100多个操纵与GCDS相关的因子的实验进行的全球综合中，我们表明草本植物群落的反应取决于实验操纵的长度和操纵的因子的数量。我们发现，植物群落在短期内(10年)对实验操作的GCDS具有相当的抵抗力。相比之下，长期(=10年)实验表明，处理与控制条件的社区差异越来越大。令人惊讶的是，这些社区反应在我们数据库中操纵的GCD类型中以相似的频率发生。然而，当3个或更多的GCD同时被操纵时，社区反应更常见，这表明出现了多个驱动因素的相加或协同效应，特别是在很长一段时间内。在一半的情况下，GCD操作引起了群落组成的差异，但没有相应的物种丰富度差异，这表明物种重新排序或替换是群落对GCDS做出反应的重要机制，在研究GCDS对生物多样性-生态系统功能关系的影响时，应该给予更多的考虑。人类活动目前正在推动全球范围内前所未有的全球变化。我们的分析提供了迄今为止最全面的证据，表明这些人类活动可能对全球植物群落组成产生广泛影响，随着时间的推移，这种影响的频率将会增加，在社区同时面临多个GCD的地区会更大。
Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (< 10 y). In contrast, long-term (>= 10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity-ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.