The dynamics of ecosystem restoration: theoretical considerations on the basis of species richness

Abstract

Much recent research on ecosystem restoration has focused on specific cases, restoration mechanisms, and techniques in the field. However, there has been less emphasis on the theoretical aspects. Here, species richness is considered as an indicator of ecosystem restoration. The dynamic process of ecosystem restoration is put into a coordinate system consisting of species richness s and time t. The factors affecting ecosystem restoration are introduced into the system to develop dynamic models describing the ecosystem restoration process. We propose that the forces controlling the restoration process include ecosystem restoration force (F1), disturbance force (F2), environmental resistance force (F3), resistance force to disturbance (F4), and the resultant force F, and develop models for their calculation. These forces are functions of time, climate, species immigration rate, disturbance, species richness, and soil nutrient heterogeneity. Disturbance force (F2) and resistance force to disturbance (F4) are positively related to species richness. Our models suggest that the velocity differential ψ of the change in species richness is inversely proportional to species richness and directly proportional to the resultant force F of ecosystem restoration. In the presence of a harmful disturbance, species richness is always lower than maximum species richness sm. The lower the primary richness s0 and immigration rate r in ecosystem restoration, the more obvious the logistic characteristics of the curve of the dynamic process. The dynamic models can be used to predict the restoration of species richness and analyze its dynamic mechanism, and assess the potential for ecosystem restoration. This integrated approach provides a new understanding of ecosystem restoration.