Analysis of degraded evergreen broad-leaved forest communities in Eastern China and issues in forest restoration

Evergreen broad-leaved forest (EBLF) is now recognized as an important natural resource that contributes to both the biodiversity and the sustainable development of the subtropical regions of China. However, the extent of the EBLF has decreased very significantly due to long-term anthropogenic disturbance including deforestation, logging and fire, and much of it is now degraded to plantation, secondary forests and shrub and grassland communities. Therefore, close attention needs to be focused on the characteristics of these degraded communities with a view to the possibilities for restoration of EBLF. Following comprehensive investigation of typical degraded EBLF in the Tiantong and Dongqian lake region of eastern China, the community types and their characteristic species composition were defined at the regional scale. The results raise several issues about degraded EBLF vegetation and its potential for restoration, which require further detailed research in order to facilitate the development of EBLF ecosystem restoration in China. These issues are (1) Given the importance of anthropogenic disturbance and land use change in determining the composition of the degraded communities, more emphasis should be placed on the relationships between them, and this should become a major focus for future research; (2) The degraded communities of EBLF contain a comparatively high plant species richness and are also characterized by a specific species composition, which make a significant contribution to the maintenance of both regional and local biodiversity; (3) The importance of sprouting of both trees and shrubs as a mechanism for species persistence and regrowth has not been given sufficient recognition. Sprouting allows species to persist in a site even after a wide range of disturbances over hundreds of years. Sprouting ability therefore can have major impacts on species turnover, changes in community structure and species composition, maintenance of biological diversity and is vital to understanding of the vegetation dynamics of EBLF; (4) Seed dispersal pattern has long been considered an important influence on the regeneration of vegetation, and it should strongly influence the distribution of tree recruits in the degraded communities. Nonetheless, seed dispersal patterns for such species are poorly known, and processes controlling the fate of seeds in the degraded community of EBLF have been little studied. Attention to these research areas is essential to the future conservation and restoration of EBLF in China.