Byun Chaeho, Lee Eun Ju
School of Civil and Environmental Engineering Yonsei University Seoul Korea.
School of Biological Sciences Seoul National University Seoul Korea.
Ecol Evol. 2017 Mar 2;7(7):2181-2192. doi: 10.1002/ece3.2799. eCollection 2017 Apr.
Biotic resistance is the ability of species in a community to limit the invasion of other species. However, biotic resistance is not widely used to control invasive plants. Experimental, functional, and modeling approaches were combined to investigate the processes of invasion by (white snakeroot) a model invasive species in South Korea. We hypothesized that (1) functional group identity would be a good predictor of biotic resistance to , whereas a species identity effect would be redundant within a functional group, and (2) mixtures of species would be more resistant to invasion than monocultures. We classified 37 species of native plants into three functional groups based on seven functional traits. The classification of functional groups was based primarily on differences in life longevity and woodiness. A competition experiment was conducted based on an additive competition design with and monocultures or mixtures of resident plants. As an indicator of biotic resistance, we calculated a relative competition index (RCI ) based on the average performance of in a competition treatment compared with that of the control where only seeds of were sown. To further explain the effect of diversity, we tested several diversity-interaction models. In monoculture treatments, RCI of resident plants was significantly different among functional groups but not within each functional group. Fast-growing annuals (FG1) had the highest RCI , suggesting priority effects (niche pre-emption). RCI of resident plants was significantly greater in a mixture than in a monoculture. According to the diversity-interaction models, species interaction patterns in mixtures were best described by interactions between functional groups, which implied niche partitioning. Functional group identity and diversity of resident plant communities were good indicators of biotic resistance to invasion by introduced , with the underlying mechanisms likely niche pre-emption and niche partitioning. This method has most potential in assisted restoration contexts, where there is a desire to reintroduce natives or boost their population size due to some previous level of degradation.
生物抗性是指群落中的物种限制其他物种入侵的能力。然而，生物抗性在控制入侵植物方面并未得到广泛应用。我们结合实验、功能和建模方法，研究了韩国一种典型入侵物种（白蛇根）的入侵过程。我们假设：（1）功能群特性是生物抵抗白蛇根入侵的良好预测指标，而在一个功能群内物种特性的影响是多余的；（2）物种混合群落比单一栽培群落更能抵抗入侵。我们根据七个功能性状将37种本地植物分为三个功能群。功能群的分类主要基于寿命和木质化程度的差异。基于加法竞争设计，对白蛇根与本地植物单一栽培或混合栽培进行了竞争实验。作为生物抗性的指标，我们根据白蛇根在竞争处理中的平均表现与仅播种白蛇根种子的对照处理中的平均表现，计算了相对竞争指数（RCI）。为了进一步解释多样性的影响，我们测试了几个多样性-相互作用模型。在单一栽培处理中，本地植物的RCI在功能群之间存在显著差异，但在每个功能群内部没有显著差异。快速生长的一年生植物（FG1）的RCI最高，表明存在优先效应（生态位抢占）。本地植物在混合群落中的RCI显著高于单一栽培群落。根据多样性-相互作用模型，混合群落中的物种相互作用模式最好用功能群之间的相互作用来描述，这意味着生态位划分。本地植物群落的功能群特性和多样性是抵抗外来白蛇根入侵的生物抗性的良好指标，其潜在机制可能是生态位抢占和生态位划分。这种方法在辅助恢复环境中最具潜力，在这种环境中，由于先前的某种程度的退化，人们希望重新引入本地物种或增加其种群数量。
