Molofsky Jane, Bever James D
Department of Botany, University of Vermont, Burlington, VT 05405, USA.
Proc Biol Sci. 2002 Dec 7;269(1508):2389-93. doi: 10.1098/rspb.2002.2164.
Theories to explain the diversity of species have required that individual species occupy unique niches and/or vary in their response to environmental factors. Positive interactions within a species, although common in communities, have not been thought to maintain species diversity because in non-spatial models the more abundant species always outcompetes the rarer species. Here, we show, using a stochastic spatial model, that positive intraspecific interactions such as those caused by positive frequency dependence and/or priority effects, can maintain species diversity if interactions between individuals are primarily local and the habitat contains areas that cannot be colonized by any species, such as boulders or other physical obstructions. When intraspecific interactions are primarily neutral, species diversity will eventually erode to a single species. When the landscape is homogeneous (i.e. does not contain areas that cannot be colonized by any species), the presence of strong intraspecific interactions will not maintain diversity.
用以解释物种多样性的理论认为，每个物种都占据着独特的生态位，并且/或者在对环境因素的反应上存在差异。物种内部的正向相互作用在群落中很常见，但人们认为这种相互作用并不能维持物种多样性，因为在非空间模型中，数量较多的物种总是会胜过数量较少的物种。在此，我们通过一个随机空间模型表明，如果个体之间的相互作用主要是局部性的，并且栖息地包含任何物种都无法定殖的区域，如巨石或其他物理障碍物，那么由正频率依赖性和/或优先效应引起的种内正向相互作用能够维持物种多样性。当种内相互作用主要是中性的时候，物种多样性最终会逐渐减少至单一物种。当景观是均质的（即不包含任何物种都无法定殖的区域）时，强烈的种内相互作用的存在并不能维持多样性。
