Department of Botany and Plant Sciences, University of California, Riverside, California 92521-0124, USA.
Ann N Y Acad Sci. 2010 May;1195 Suppl 1:E27-39. doi: 10.1111/j.1749-6632.2009.05399.x.
An exotic species can be a superior colonizer but inferior resource competitor relative to native species. Such species can spatially coexist for an extended period of time in a community maintained via competition-colonization (CC) trade-offs. Whether fluctuations in resource supply allow such exotic species to successfully invade and displace the native species or hold the coexistence is not previously explored, and it is the focus of this study. In this article, we model propagule-limited spatial competition explicitly linked with resource-competition within the framework of the classic CC-model, while time-dependent fluctuations in resource supply are considered in a sinusoidal function. The model predicts that if the amplitude of the fluctuations is greater than the average resource supply rate, there exist a range of values of fluctuation frequency that can allow the exotic species to successfully invade the habitat and to reduce the extent of native species. On the other hand, if the fluctuation amplitude is less than the average resource supply rate, such exotic species can coexist with the native species, independent of fluctuation frequencies. In addition, we found that at a constant resource supply rate, the exotic species can stably coexist with the native species at competitive equilibrium.
外来物种可能是优越的殖民者，但相对于本地物种而言，其资源竞争能力较差。在通过竞争-殖民（CC）权衡来维持的群落中，这种物种可以在很长一段时间内在空间上共存。资源供应的波动是否允许这些外来物种成功入侵并取代本地物种，或者维持共存状态，这一点尚未得到探索，也是本研究的重点。在本文中，我们在经典 CC 模型的框架内，明确地将受限制传播的空间竞争与资源竞争联系起来，同时考虑资源供应的时间依赖性波动呈正弦函数形式。模型预测，如果波动幅度大于平均资源供应率，则存在一个波动频率范围，使外来物种能够成功入侵栖息地并减少本地物种的范围。另一方面，如果波动幅度小于平均资源供应率，则这种外来物种可以与本地物种共存，而不受波动频率的影响。此外，我们发现，在恒定的资源供应率下，外来物种可以在竞争平衡时与本地物种稳定共存。
