Centre for Ecology and Hydrology, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK.
Centre for Conservation Ecology and Environmental Science, School of Applied Sciences, Bournemouth University, Poole, BH12 5BB, UK.
Ecology. 2017 Apr;98(4):1026-1035. doi: 10.1002/ecy.1711.
Invasive plants can alter ecosystem properties, leading to changes in the ecosystem services on which humans depend. However, generalizing about these effects is difficult because invasive plants represent a wide range of life forms, and invaded ecosystems differ in their plant communities and abiotic conditions. We hypothesize that differences in traits between the invader and native species can be used to predict impacts and so aid generalization. We further hypothesize that environmental conditions at invaded sites modify the effect of trait differences and so combine with traits to predict invasion impacts. To test these hypotheses, we used systematic review to compile data on changes in aboveground and soil carbon pools following non-native plant invasion from studies across the World. Maximum potential height (H ) of each species was drawn from trait databases and other sources. We used meta-regression to assess which of invasive species' H , differences in this height trait between native and invasive plants, and climatic water deficit, a measure of water stress, were good predictors of changes in carbon pools following invasion. We found that aboveground biomass in invaded ecosystems relative to uninvaded ones increased as the value of H of invasive relative to native species increased, but that this effect was reduced in more water stressed ecosystems. Changes in soil carbon pools were also positively correlated with the relative H of invasive species, but were not altered by water stress. This study is one of the first to show quantitatively that the impact of invasive species on an ecosystem may depend on differences in invasive and native species' traits, rather than solely the traits of invasive species. Our study is also the first to show that the influence of trait differences can be altered by climate. Further developing our understanding of the impacts of invasive species using this framework could help researchers to identify not only potentially dangerous invasive species, but also the ecosystems where impacts are likely to be greatest.
入侵植物会改变生态系统的属性，导致人类赖以生存的生态系统服务发生变化。然而，要对这些影响进行概括是很困难的，因为入侵植物代表了广泛的生活形式，而被入侵的生态系统在其植物群落和非生物条件方面存在差异。我们假设，入侵物种和本地物种之间的特征差异可以用来预测影响，从而有助于概括。我们进一步假设，入侵地点的环境条件会改变特征差异的影响，从而与特征相结合来预测入侵的影响。为了检验这些假设，我们使用系统综述，从全球各地的研究中汇编了关于非本地植物入侵后地上和土壤碳库变化的数据。每个物种的最大潜在高度（H）取自特征数据库和其他来源。我们使用元回归来评估入侵物种的 H、本地和入侵植物之间该高度特征的差异以及气候水分亏缺（衡量水分胁迫的指标）哪个是入侵后碳库变化的良好预测因子。我们发现，与未受入侵的生态系统相比，入侵生态系统中的地上生物量随着入侵物种相对于本地物种的 H 值的增加而增加，但在水分胁迫较大的生态系统中，这种效应会减弱。土壤碳库的变化也与入侵物种的相对 H 值呈正相关，但不受水分胁迫的影响。这项研究首次定量表明，入侵物种对生态系统的影响可能取决于入侵和本地物种特征的差异，而不仅仅是入侵物种的特征。我们的研究也是首次表明，特征差异的影响可以被气候改变。进一步利用这一框架来深入了解入侵物种的影响，可以帮助研究人员不仅识别出潜在危险的入侵物种，还能识别出可能产生最大影响的生态系统。
