Disturbance and diversity in experimental microcosms

摘要: External agents of mortality (disturbances) occur over a wide range scales space and time, are believed to have large effects on species diversity. The “intermediate disturbance hypothesis”1,2,3, which proposes maximum diversity at intermediate frequencies disturbance, has received support from both field4,5 laboratory6,7 studies. Coexistence is thought require trade-offs between competitive ability tolerance8, metapopulation structure, with affecting only few patches any given time9,10,11. However, unimodal relationship can also be generated by global disturbances that affect all simultaneously, provided the environment contains spatial niches different adapted12. Here we report results tests this model using isogenic diverse populations bacterium Pseudomonas fluorescens. In cases, frequency was in heterogeneous, but not homogeneous, environments. cause competition among niche-specialist genotypes, maintains high or low disturbance. Our show modulate effect heterogeneity biological natural