Abstract:

Based on a survey of the population composition of plant communities, the main tree species population structure of three typical forests was analyzed and the succession trends of communities were deduced in the Three Gorges Reservoir Area. The results showed that: 1) The dominant species in the arbor layer included coniferous trees (Pinus massoniana, Cupressus funebris etc.), deciduous broad-leaved trees (Quercus glanduifera, Quercus variabilis etc.), and evergreen broad-leaved trees Cyclobalanopsis multineryius, Lithocarpus glaber etc.). 2) The height class frequency peak in coniferous forest arbor layer was 10～15 m, while that in coniferous-broadleaved and broadleaved forest was 5～10 m. 3) The DBH class frequency distributions of dominated species in broadleaved forest displayed an inverse-J pattern, while that of companion species was L or inverse-J pattern. The population size structure of main tree species indicated the community appeared stable. 4) The population of dominant coniferous species in coniferous-broadleaved forest community was declining, presenting unimodal, inverse-J shape, while those of broadleaved dominated species were gradually increasing, with L type or intermittent increasing multimodal type. 5) The DBH class frequency distribution of dominant species in coniferous forest was typical unimodal, while those of the companion species were unibar type or L type. 6) The forest succession procedure in the Three Gorges Reservoir Area was deduced with the population size structure of main tree species, such as the coniferous forest community →the broadleaf and conifer mixed forest community → the evergreen broad-leaved forest community. The results provided scientific basis for eco-construction and forest resources management in Three Gorges Reservoir Area.

Key words: dominant species, DBH class frequency, regeneration type, succession, Three Gorges Reservoir Area