Abstract:

Sixteen quadrats were selected from the ravine secondary forest of Mengshan to analyze the community structure and species diversity.The results show:1) The ravine secondary forest community of Mengshan includes at least 28 species of tree layer plants,39 species of shrub layer plants and 49 species of herb layer plants.The individual densities of tree,shrub and herb plant types are 1.425 plants/m²,8.892 plants/m² and 11.73 plants/m².28 species of trees are classified into 12 extended species,2 recessive species,6 stable invaded species and 8 randomly recessive species according to the structure.2) There are two types of diameter classes of the main tree species in the ravine secondary forest of Mengshan:Quercus variabilis,Quercus acutissima,Dalbergia hupeana,Quercus dentate,Celtis sinensis,Diospyros lotus and Celtis koraiensis are growth types.Pinus thunbergii and Pinus densiflora are stable types.3) In the ravine secondary forest of Mengshan,Shannon-Wiener diversity index and Simpson diversity index shows the order of shrub layer>tree layer>herb layer,while Pielou evenness index shows the order of herb layer>shrub layer>tree layer.The results can provide scientific basis and data reference for Yimeng mountainous area and northern rocky mountains.

Key words: Mengshan, ravine, secondary forest, population characteristics, community composition, species diversity