Binama Blaise, Caroline Müller
Department of Chemical Ecology Bielefeld University Bielefeld Germany.
Ecol Evol. 2024 Mar 18;14(3):e11153. doi: 10.1002/ece3.11153. eCollection 2024 Mar.
The global shift of species' distributions has led to high numbers of noninvasive naturalized plants and the accumulation of invasive species within ecosystems. Competition between species may influence population dynamics, but little is known about the impacts of competition between conspecifics of naturalized and invasive populations. We investigated several plant traits at initial growth and regrowth following artificial defoliation in intra and interpopulation competition. Therefore, we used plants of from one noninvasive naturalized and one invasive population grown alone or in competition of two or three. Plants from the naturalized population were expected to be less competitive than plants from the invasive population, reflecting their differential impact in the introduced range. Independent of status, intrapopulation competition was expected to have less negative impacts on plants than interpopulation competition. Our results show that competition impacted mostly growth- rather than physiology-related traits. The relative magnitude of intra and interpopulation competition differed among plant traits at the first and second harvest. Plants of the invasive population outperformed the naturalized population by allocating relatively more resources to the aboveground biomass and producing more and longer leaves particularly when grown in competition against two plants. Moreover, plants of the invasive population were more competitive, which may influence their successful establishment and range expansion in the introduced range, but growth patterns differed after artificial defoliation. Although evolution of intrapopulation competition in naturalized and invasive ranges may be expected, interpopulation competition seems to adversely impact the performance of the naturalized plant population of studied here. Apart from the status (naturalized vs. invasive), other factors may have had an influence on plant performance. Thus, further research is needed with more naturalized and invasive populations to test the generality of our findings and to isolate the specific mechanisms driving differences in competitiveness.
物种分布的全球变化导致了大量非入侵性归化植物的出现以及生态系统中入侵物种的积累。物种间的竞争可能会影响种群动态，但对于归化种群和入侵种群的同种个体之间竞争的影响却知之甚少。我们研究了人工去叶后种群内和种群间竞争中植物在初始生长和再生阶段的几个植物性状。因此，我们使用了来自一个非入侵性归化种群和一个入侵种群的植物，这些植物单独生长或在两株或三株植物的竞争环境中生长。预计归化种群的植物竞争力低于入侵种群的植物，这反映了它们在引入范围内的不同影响。无论种群状态如何，预计种群内竞争对植物的负面影响要小于种群间竞争。我们的结果表明，竞争主要影响与生长相关而非生理相关的性状。在第一次和第二次收获时，种群内和种群间竞争的相对强度在不同植物性状间存在差异。入侵种群的植物通过将相对更多的资源分配到地上生物量中，尤其是在与两株植物竞争生长时，长出更多更长的叶子，从而表现优于归化种群。此外，入侵种群的植物更具竞争力，这可能会影响它们在引入范围内的成功定植和范围扩展，但人工去叶后的生长模式有所不同。虽然预计归化和入侵范围内种群内竞争会发生进化，但种群间竞争似乎对本文研究的归化植物种群的表现产生了不利影响。除了种群状态（归化与入侵）外，其他因素可能也对植物表现产生了影响。因此，需要对更多的归化和入侵种群进行进一步研究，以检验我们研究结果的普遍性，并分离出驱动竞争力差异的具体机制。
