Disturbance, diversity and stability of ecological systems – the need fora uniform hypothesis

摘要

One of the most consistent criticisms in ecological sciences is the continuing failure of ecologists to define concepts and to formulate general theories1,2. Here we compare the net effect of two fundamental hypotheses of diversity, stability and disturbance. According to the first hypothesis, i.e. the Diversity Insurance Hypothesis3,4, which relates diversity with ecological stability, greater ecological diversity leads to greater ecosystem stability (Figure 1). According to the second hypothesis, i.e. the Intermediate Disturbance Hypothesis, intermediate disturbances enhance ecological diversity5 (Figure 2). The lower limit of this hypothesis cautions that if disturbances are too rare, competitive dominants eliminate other species and reduce diversity as equilibrium conditions develop. The upper limit cautions that if disturbances are too frequent, most species will go locally extinct because they cannot tolerate repeated disturbances, resulting in lower diversity.