Functional traits predict species responses to environmental variation in a California grassland annual plant community
Functional traits predict species responses to environmental variation in a California grassland annual plant community
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DOI：
10.1111/1365-2745.13845
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发表时间：
2022-02-12
影响因子：
5.5
通讯作者：
Kraft, Nathan J. B.
中科院分区：
文献类型：
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作者：
Kandlikar, Gaurav S.;Kleinhesselink, Andrew R.;Kraft, Nathan J. B.
1.在物种组成和植物群落中的优势功能策略在环境梯度上的周转是整个生物群落的一种常见模式，通常被认为反映了性状最优的变化。然而，在何种程度上社区范围内的性状周转模式反映了植物性状如何影响生命率，最终决定健身的变化仍然不清楚。我们测试了在加州南部草原的环境梯度中，四个关键功能性状的群落加权平均值的变化是否反映了这些性状如何影响物种的发芽和繁殖力的变化。我们问是否包括性状-环境相互作用的模型有助于解释两个关键的生命率（发芽率和繁殖力）的变化，以及结合两个生命率（发芽率和繁殖力的产品）的健身的综合措施。为了做到这一点，我们在16个地点种植了17种一年生植物的种子，在没有竞争对手的情况下清除补丁，并量化了1360个个体的一生种子产量。我们还测量了同一地点的群落组成和各种非生物变量。这使我们能够评估观察到的群体加权平均性状的变化是否与植物性能实验中检测到的任何性状-环境相互作用的方向相匹配。我们发现，通常测量的植物功能性状确实有助于解释物种对环境的反应变化，例如，高SLA物种在土壤Ca：Mg水平高的地点具有人口优势（较高的发芽率和繁殖力），而低SLA物种在低Ca：Mg土壤中具有优势。我们还发现，社区加权平均性状的变化通常反映了这些性状-环境相互作用的方向，尽管并非所有社区水平的性状-环境关系都反映了这些梯度中最佳性状值的变化。合成.我们的研究结果表明，性状-适应度关系的变化如何引起植物表型在环境梯度中的周转，这是生态学中的一种基本模式。我们强调植物功能性状在预测物种对环境变化的反应中的价值，并强调需要更广泛地研究性状-性能关系，以提高对全球变化的社区反应的预测。
1. Turnover in species composition and the dominant functional strategies in plant communities across environmental gradients is a common pattern across biomes, and is often assumed to reflect shifts in trait optima. However, the extent to which community-wide trait turnover patterns reflect changes in how plant traits affect the vital rates that ultimately determine fitness remain unclear.2. We tested whether shifts in the community-weighted means of four key functional traits across an environmental gradient in a southern California grassland reflect variation in how these traits affect species' germination and fecundity across the landscape.3. We asked whether models that included trait-environment interactions help explain variation in two key vital rates (germination rates and fecundity), as well as an integrative measure of fitness incorporating both vital rates (the product of germination rate and fecundity). To do so, we planted seeds of 17 annual plant species at 16 sites in cleared patches with no competitors, and quantified the lifetime seed production of 1360 individuals. We also measured community composition and a variety of abiotic variables across the same sites. This allowed us to evaluate whether observed shifts in community-weighted mean traits matched the direction of any trait-environment interactions detected in the plant performance experiment.4. We found that commonly measured plant functional traits do help explain variation in species responses to the environment-for example, high-SLA species had a demographic advantage (higher germination rates and fecundity) in sites with high soil Ca:Mg levels, while low-SLA species had an advantage in low Ca:Mg soils. We also found that shifts in community-weighted mean traits often reflect the direction of these trait-environment interactions, though not all trait-environment relationships at the community level reflect changes in optimal trait values across these gradients.5. Synthesis. Our results show how shifts in trait-fitness relationships can give rise to turnover in plant phenotypes across environmental gradients, a fundamental pattern in ecology. We highlight the value of plant functional traits in predicting species responses to environmental variation, and emphasise the need for more widespread study of trait-performance relationships to improve predictions of community responses to global change.