Compensation and the stability of restored grassland communities.

The relationship between community diversity and the stability of summed community biomass has been an area of great theoretical and empirical interest in basic ecology. In general, it has been found that the complementary/compensatory dynamics among species that comprise a community can stabilize aggregate measures of community biomass. Although the potential importance of diversity-stability relationships to restoration ecology has been recognized, to date there has been no quantification of the role these relationships play in increasing the persistence of restored communities in the face of altered disturbance regimes, climatic variability, and over the course of succession. In a large-scale experimental restoration of a California grassland community, aggregated abundance of restored grasses was more stable than were the individual species in response to disturbance, drought, and succession. Compensatory dynamics among the restored grass flora increased aggregate stability in response to natural and anthropogenic disturbances. Successful restorations must persist in the face of altered management and disturbance regimes, climactic variability, and over the course of succession. Incorporation of diversity-stability relationships into restoration plans will likely increase restoration success. This case study further demonstrates the relevance of community ecology theory to restoration ecology.