[Dynamic principle of ecosystem restoration based on plant diversity]

The dynamics of ecosystem restoration is an important issue in ecology. Based on the theories of island biogeography, plant community succession, biodiversity sustaining mechanism and ecosystem function, a dynamic model of ecosystem restoration was deduced, and verified by the observation data on semi-humid evergreen broadleaved forest at its secondary succession phase. The dynamic principle was discussed based on the analysis of the nature of the dynamic model. It was indicated that the dynamic process of ecosystem restoration was controlled by the integrative effect of ecosystem restoration force F1, disturbance force F2 and environmental resistance F3. The change rate of plant diversity restoration was in inverse proportion to plant species richness, and in direct proportion to the total driving force of ecosystem restoration F. F1 and F3 were the functions of initial species richness s0 and environmental resources of restoring ecosystem, while F2 was the function of disturbance intensity and species richness. When the ecosystem was under negative disturbance, plant species richness was always lower than the highest species richness sm. The smaller the s0, the stronger logistic the ecosystem restoration process would be. Mathematical models were established to calculate F1, F2 and F3, and to estimate the effects of plant diversity and disturbance on ecosystem restoration. It was suggested that the increase of plant species richness could enhance ecosystem restoration potential, and promote ecosystem stability.