Does environmental heterogeneity drive functional trait variation? A test in montane and alpine meadows
Does environmental heterogeneity drive functional trait variation? A test in montane and alpine meadows
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DOI：
10.1111/oik.04311
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发表时间：
2017-11
期刊：
影响因子：
3.4
通讯作者：
J. Stark;R. Lehman;L. Crawford;B. Enquist;B. Blonder
中科院分区：
文献类型：
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作者：
J. Stark;R. Lehman;L. Crawford;B. Enquist;B. Blonder
虽然植物性状的群落加权平均值与大范围的平均环境条件相关，但群落内性状变异的驱动因素尚不清楚。除了平均环境条件之外，当地环境异质性（例如小气候变异性）可能会降低环境过滤的强度，并解释为什么社区支持不同数量的性状变异。在这里，我们评估两个假设：第一，更异质的当地环境，第二，不太极端的环境，应该支持更广泛的植物策略，从而支持更高的性状变异。我们量化了山地和高山植物群落中从亚米级到数十公里的一系列环境条件和空间尺度的性状变异驱动因素。我们发现，在社区内，环境异质性和环境手段都是性状变异的驱动因素。然而，每个环境因素的重要性因性状而异。我们的结果表明，跨群落的更大规模的性状-气候联系也适用于小空间尺度，这表明群落内的小气候变化是群落功能多样性的关键驱动因素。小气候变化提供了一种有助于维持当地社区多样性的潜在机制，并且还表明应该测量小规模环境异质性，作为功能多样性的更好预测指标。本文受版权保护。版权所有。
While community-weighted means of plant traits have been linked to mean environmental conditions at large scales, the drivers of trait variation within communities are not well understood. Local environmental heterogeneity (such as microclimate variability), in addition to mean environmental conditions, may decrease the strength of environmental filtering and explain why communities support different amounts of trait variation. Here, we assess two hypotheses: first, that more heterogeneous local environments and second, that less extreme environments, should support a broader range of plant strategies and thus higher trait variation. We quantified drivers of trait variation across a range of environmental conditions and spatial scales ranging from sub-meter to tens of kilometers in montane and alpine plant communities. We found that, within communities, both environmental heterogeneity and environmental means are drivers of trait variation. However, the importance of each environmental factor varied depending on the trait. Our results indicate that larger-scale trait-climate linkages that hold across communities also apply at small spatial scales, suggesting that microclimate variation within communities is a key driver of community functional diversity. Microclimatic variation provides a potential mechanism for helping to maintaining diversity in local communities and also suggests that small-scale environmental heterogeneity should be measured as a better predictor of functional diversity. This article is protected by copyright. All rights reserved.