Department of Plant Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands.
Smithsonian Tropical Research Institute, Apartado Postal, 0843-03092, Balboa, Ancón, Panamá.
Ecol Lett. 2019 Nov;22(11):1957-1975. doi: 10.1111/ele.13349. Epub 2019 Jul 21.
Many empirical studies motivated by an interest in stable coexistence have quantified negative density dependence, negative frequency dependence, or negative plant-soil feedback, but the links between these empirical results and ecological theory are not straightforward. Here, we relate these analyses to theoretical conditions for stabilisation and stable coexistence in classical competition models. By stabilisation, we mean an excess of intraspecific competition relative to interspecific competition that inherently slows or even prevents competitive exclusion. We show that most, though not all, tests demonstrating negative density dependence, negative frequency dependence, and negative plant-soil feedback constitute sufficient conditions for stabilisation of two-species interactions if applied to data for per capita population growth rates of pairs of species, but none are necessary or sufficient conditions for stable coexistence of two species. Potential inferences are even more limited when communities involve more than two species, and when performance is measured at a single life stage or vital rate. We then discuss two approaches that enable stronger tests for stable coexistence-invasibility experiments and model parameterisation. The model parameterisation approach can be applied to typical density-dependence, frequency-dependence, and plant-soil feedback data sets, and generally enables better links with mechanisms and greater insights, as demonstrated by recent studies.
许多出于对稳定共存的兴趣而进行的实证研究量化了负密度依赖、负频率依赖或负植物-土壤反馈，但这些实证结果与生态理论之间的联系并不直接。在这里，我们将这些分析与经典竞争模型中稳定化和稳定共存的理论条件联系起来。通过稳定化，我们指的是种内竞争相对于种间竞争的过度，这会内在地减缓甚至防止竞争排斥。我们表明，大多数（尽管不是全部）证明负密度依赖、负频率依赖和负植物-土壤反馈的测试，如果应用于两个物种的个体种群增长率数据，构成了两种相互作用稳定化的充分条件，但对于两种物种的稳定共存来说，它们既不是必要条件，也不是充分条件。当群落涉及两个以上物种时，以及当性能在单个生命阶段或关键比率上进行测量时，潜在的推断甚至更加有限。然后，我们讨论了两种能够更有力地检验稳定共存-入侵性实验和模型参数化的方法。模型参数化方法可以应用于典型的密度依赖、频率依赖和植物-土壤反馈数据集，并且通常能够更好地与机制联系起来，并提供更多的见解，正如最近的研究所示。
