Plant functional traits reflect different dimensions of species invasiveness
Plant functional traits reflect different dimensions of species invasiveness
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DOI：
10.1002/ecy.3317
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发表时间：
2021-04-20
期刊：
影响因子：
4.8
通讯作者：
Catford, Jane A.
中科院分区：
文献类型：
--
作者：
Palma, Estibaliz;Vesk, Peter A.;Catford, Jane A.
基于特征的入侵性研究通常将外来物种分类为入侵性或非入侵性，隐含地假设物种形成两个同质群体。然而，物种可以以不同的方式成为入侵者（例如，高丰度，快速传播），可能依赖于不同的功能特性来做到这一点。因此，二元分类可能会掩盖与侵袭性相关的特征。我们测试了（1）入侵性的量化方式是否会影响其与功能性状的相关性，以及（2）不同的基于人口统计学的指标是否与不同的性状相关。使用对澳大利亚维多利亚251种外来草药的案例研究，我们使用10个指标量化了物种的入侵性：四个连续的、基于人口统计的入侵性维度（传播率、当地丰度、地理和环境范围大小）和六个二元入侵性分类（基于替代来源和入侵标准）。我们研究了物种的入侵性和一组四个特征之间的相关性，这些特征与植物的人口统计和入侵有关。然后，我们研究了不同的人口统计学维度的入侵性是否更好地解释了不同的特征。我们发现，入侵性的量化方式很重要：不同的性状与不同的入侵性指标有关，有些性状在不同的指标上表现出相反的效果。快速传播的物种要么是高大的小种子（即，良好的殖民者），或者有沉重的，动物分散的种子。环境适应范围大的植物，某些性状的可塑性更大。当地丰富的植物具有低SLA和重种子（即，强大的竞争对手）。动物的分散也是达到大的地理范围的关键。没有性状始终相关的六个二元分类。我们的研究结果表明，外来植物是以不同的方式入侵，并依赖于不同的特征组合。一些特征（例如，种子质量）与入侵的关系复杂：它们显然促进，阻碍，或没有影响的不同方面的入侵。我们的研究结果是一致的概念，植物物种使用的策略，可能是接近最佳的一些，但不是所有的生态条件下。与侵袭性的二元分类相比，侵袭性维度的使用在侵袭科学中推进了更清晰的假设检验。
Trait-based invasiveness studies typically categorize exotic species as invasive or noninvasive, implicitly assuming species form two homogenous groups. However, species can become invasive in different ways (e.g., high abundance, fast spread), likely relying on different functional traits to do so. As such, binary classification may obscure traits associated with invasiveness. We tested whether (1) the way in which invasiveness is quantified influences its correlation with functional traits and (2) different demography-based metrics are related to different sets of traits. Using a case study of 251 herbs exotic to Victoria, Australia, we quantified species' invasiveness using 10 metrics: four continuous, demography-based dimensions of invasiveness (spread rate, local abundance, geographic and environmental range sizes) and six binary classifications of invasiveness (based on alternative sources and invasion criteria). We examined the correlation between species' invasiveness and a set of four traits known to relate to plant demography and invasion. Then, we examined whether different demographic dimensions of invasiveness were better explained by different sets of traits. We found that the way invasiveness was quantified was important: different traits were linked with different invasiveness metrics, and some traits showed opposite effects across metrics. Species with fast spread were either tall with small seeds (i.e., good colonizers), or had heavy, animal-dispersed seeds. Plants with a large environmental range had greater plasticity for some traits. Locally abundant plants had low SLA and heavy seeds (i.e., strong competitors). Animal dispersal was also key to reach a large geographic range. No traits were consistently related to the six binary classifications. Our results indicate that exotic plants are invasive in different ways and rely on different combinations of traits to be so. Some traits (e.g., seed mass) had complex relationships with invasion: they apparently promote, hampered, or had no influence on different dimensions of invasiveness. Our findings are consistent with the notion that plant species use strategies that may be near optimal under some, but not all, ecological conditions. Compared to binary classifications of invasiveness, the use of invasiveness dimensions advances clearer hypothesis testing in invasion science.