Figure 18.22 Species richness and community stability. Researchers manipulated the species richness of plants and then monitored the stability of the abundance and species richness of invertebrate herbivores, predators, and parasitoids. (a) An increase in the diversity of plants caused greater stability of richness and abundance of herbivores. (b) An increase in the diversity of plants also caused greater stability of richness of predators and parasitoids, but had no effect on the stability of abundance. In all cases, stability is defined as the inverse of the coefficient of variation, which is the standard deviation divided by the mean. Error bars are standard errors.

Data from N. M. Haddad, Plant diversity and the stability of foodwebs, Ecology Letters 14 (2010): 42–46.