Plant functional group identity and diversity determine biotic resistance to invasion by an exotic grass
Plant functional group identity and diversity determine biotic resistance to invasion by an exotic grass
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DOI：
10.1111/1365-2745.12016
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发表时间：
2013-01-01
影响因子：
5.5
通讯作者：
Brisson, Jacques
中科院分区：
文献类型：
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作者：
Byun, Chaeho;de Blois, Sylvie;Brisson, Jacques
1.生物抗性，即群落中物种限制入侵的能力，是我们理解干扰后有入侵风险的群落如何聚集的核心，但它尚未转化为恢复抗入侵植物群落的指导原则。我们结合实验，功能和建模的方法来研究过程中的社区组装有助于生物抗性引进的谱系芦苇，在北美的模式入侵物种。我们假设（i）功能群同一性是一个很好的预测指标，而物种同一性效应在功能群内是多余的;（ii）物种混合比单作更能抵抗入侵.根据湿地植物的8个功能性状，将36种湿地植物分为4个功能类群。采用加性竞争设计，以芦苇和湿地植物的单一栽培或混合栽培进行了两个竞争试验。作为生物抗性的指标，我们计算了相对竞争指数（RCIavg）的基础上，在竞争处理的平均性能与对照相比，芦苇。为了进一步解释多样性效应，我们将其分为选择效应和互补效应，并对几种多样性-交互作用模型进行了检验.在单一栽培处理中，湿地植物的RCIavg在功能组间差异显著，但在各功能组内差异不显著。我们发现快速生长的一年生植物的RCIavg最高，表明优先效应。湿地植物的RCIavg在混植中显著大于单作，主要是由于功能群间的互补-多样性效应。在多样性-相互作用模型中，当拟合到RCIavg或生物量时，混合物中物种相互作用模式最好通过官能团之间的相互作用来描述，这意味着生态位划分。合成.功能组的身份和多样性的居民植物群落是很好的指标，生物入侵的芦苇入侵，建议生态位抢占（优先效应）和生态位分割（多样性效应）的潜在机制。理解和/或管理生物入侵的指导原则可能来自社区理论的进步和功能框架的使用。在不同的环境中以广泛分布的入侵植物为目标，并扩大到实地情况，将有助于推广。
1. Biotic resistance, the ability of species in a community to limit invasion, is central to our understanding of how communities at risk of invasion assemble after disturbances, but it has yet to translate into guiding principles for the restoration of invasion-resistant plant communities. We combined experimental, functional, and modelling approaches to investigate processes of community assembly contributing to biotic resistance to an introduced lineage of Phragmites australis, a model invasive species in North America. We hypothesized that (i) functional group identity would be a good predictor of biotic resistance to P. australis, while species identity effect would be redundant within functional group (ii) mixtures of species would be more invasion resistant than monocultures.2. We classified 36 resident wetland plants into four functional groups based on eight functional traits. We conducted two competition experiments based on the additive competition design with P. australis and monocultures or mixtures of wetland plants. As an indicator of biotic resistance, we calculated a relative competition index (RCIavg) based on the average performance of P. australis in competition treatment compared with control. To explain diversity effect further, we partitioned it into selection effect and complementarity effect and tested several diversity-interaction models.3. In monoculture treatments, RCIavg of wetland plants was significantly different among functional groups, but not within each functional group. We found the highest RCIavg for fast-growing annuals, suggesting priority effect.4. RCIavg of wetland plants was significantly greater in mixture than in monoculture mainly due to complementarity-diversity effect among functional groups. In diversity-interaction models, species interaction patterns in mixtures were described best by interactions between functional groups when fitted to RCIavg or biomass, implying niche partitioning.5. Synthesis. Functional group identity and diversity of resident plant communities are good indicators of biotic resistance to invasion by introduced Phragmites australis, suggesting niche pre-emption (priority effect) and niche partitioning (diversity effect) as underlying mechanisms. Guiding principles to understand and/or manage biological invasion could emerge from advances in community theory and the use of a functional framework. Targeting widely distributed invasive plants in different contexts and scaling up to field situations will facilitate generalization.