Molofsky J, Bever J D, Antonovics J
Department of Botany, University of Vermont, Burlington 05405, USA.
Proc Biol Sci. 2001 Feb 7;268(1464):273-7. doi: 10.1098/rspb.2000.1355.
Negative frequency dependence resulting from interspecific interactions is considered a driving force in allowing the coexistence of competitors. While interactions between species and genotypes can also result in positive frequency dependence, positive frequency dependence has usually been credited with hastening the extinction of rare types and is not thought to contribute to coexistence. In the present paper, we develop a stochastic cellular automata model that allows us to vary the scale of frequency dependence and the scale of dispersal. The results of this model indicate that positive frequency dependence will allow the coexistence of two species at a greater rate than would be expected from chance. This coexistence arises from the generation of banding patterns that will be stable over long time-periods. As a result, we found that positive frequency-dependent interactions over local spatial scales promote coexistence over neutral interactions. This result was robust to variation in boundary conditions within the simulation and to variation in levels of disturbance. Under all conditions, coexistence is enhanced as the strength of positive frequency-dependent interactions is increased.
种间相互作用产生的负频率依赖性被认为是允许竞争者共存的驱动力。虽然物种与基因型之间的相互作用也可能导致正频率依赖性，但正频率依赖性通常被认为会加速稀有类型的灭绝，并且不被认为有助于共存。在本文中，我们开发了一个随机细胞自动机模型，该模型使我们能够改变频率依赖性的尺度和扩散的尺度。该模型的结果表明，正频率依赖性将使两个物种共存的概率高于随机预期。这种共存源于带状模式的产生，这些模式在长时间内将是稳定的。因此，我们发现局部空间尺度上的正频率依赖性相互作用比中性相互作用更有利于共存。这一结果对于模拟中边界条件的变化以及干扰水平的变化具有稳健性。在所有条件下，随着正频率依赖性相互作用强度的增加，共存性增强。
