Gallagher Eugene D, Gardner G B, Jumars Peter A
Environmental Sciences Program, University of Massachusetts at Boston, 02125, Boston, MA, USA.
School of Oceanography, WB-10 University of Washington, 98195, Seattle, WA, USA.
Oecologia. 1990 Jul;83(4):427-442. doi: 10.1007/BF00317192.
Controlled experiments, designed to assess the effects of pioneers on succession on an intertidal sandflat, provided evidence for interspecific competition between juvenile Hobsonia florida (Polychaeta, Ampharetidae) and oligochaetes. The field data were fitted to both the linear Volterra and non-linear Gilpin-Ayala competition equations. With its greater number of parameters, the Gilpin-Ayala model must provide a better fit to observed population abundances. The Gilpin-Ayala model is flawed as an explanation of the population trajectories of the H. florida and oligochaetes, because its non-linearity parameter affects only intraspecific competion. With either model our field data demonstrate a solution to Hutchinson's paradox. With competition coefficients near unity and similar carrying capacities, the predicted population trajectories are heavily dependent on initial conditions. The predicted times to competitive exclusion are long and can easily exceed the typical period of environmental constancy. Our study offers evidence for Neill's competitive bottleneck: competition acts primarily on the developmental stages of one of a pair of competing species. The permanent meiofauna may act as a competitive bottleneck for the population growth of benthic macrofauna. The mechanism of this competitive interaction probably involves exploitative interspecific competition for benthic diatoms.
旨在评估先驱物种对潮间带沙滩演替影响的对照实验，为佛罗里达霍布索尼亚虫（多毛纲，Ampharetidae科）幼体与寡毛纲动物之间的种间竞争提供了证据。野外数据与线性沃尔泰拉竞争方程和非线性吉尔平 - 阿亚拉竞争方程均拟合。吉尔平 - 阿亚拉模型参数更多，必然能更好地拟合观测到的种群丰度。吉尔平 - 阿亚拉模型作为对佛罗里达霍布索尼亚虫和寡毛纲动物种群轨迹的一种解释存在缺陷，因为其非线性参数仅影响种内竞争。使用任一模型，我们的野外数据都证明了解决哈钦森悖论的一种方法。竞争系数接近1且承载能力相似时，预测的种群轨迹严重依赖初始条件。预测的竞争排斥时间很长，很容易超过环境稳定性的典型时期。我们的研究为尼尔的竞争瓶颈提供了证据：竞争主要作用于一对竞争物种中一个物种的发育阶段。永久性小型底栖动物可能是底栖大型动物种群增长的竞争瓶颈。这种竞争相互作用的机制可能涉及对底栖硅藻的剥削性种间竞争。
