Abstract:
Community dynamics are governed by two opposed processes: species sorting, which produces deterministic dynamics leading to an equilibrium state, and ecological drift, which produces stochastic dynamics. Despite a great deal of theoretical and empirical work aiming to demonstrate the predominance of one or the other of these processes, the importance of drift in structuring communities and maintaining species diversity remains contested. Here, we present the results of a basic community dynamics experiment using floating aquatic plants, designed to measure the relative contributions of species sorting and ecological drift to community change over about a dozen generations. We found that species sorting became overwhelmingly dominant as the experiment progressed, and directed communities toward a stable equilibrium state maintained by negative frequency-dependent selection. The dynamics of any particular species depended on how far its initial frequency was from its equilibrium frequency, however, and consequently the balance of sorting and drift varied among species.
摘要:
群落动态受两个相反的过程支配:物种分类,产生导致平衡状态的确定性动力学,和生态漂移,产生随机动力学。尽管大量的理论和实证工作旨在证明这些过程中的一个或另一个的优势,漂移在构建社区和维持物种多样性方面的重要性仍然存在争议。这里,我们介绍了使用漂浮水生植物的基本群落动力学实验的结果,旨在衡量物种分类和生态漂移对大约十几代人社区变化的相对贡献。我们发现随着实验的进行,物种分类变得压倒性地占主导地位,并将社区引向由负频率依赖性选择维持的稳定平衡状态。任何特定物种的动力学取决于其初始频率与平衡频率的距离,然而,因此,分类和漂移的平衡因物种而异。