Abstract:

Dynamics of a degraded Karst forest in the process of natural restoration,Maolan National Reserve in Guizhou province was studied.The structure of adaptive grade species groups was taken to indicated the change of species composition.The dominator in succession stages was pioneer species in herbaceous and herbaceous scrub stages,sub pioneer species and transition species in scrub shrub and shrub tree stages,sub climax species and climax species in evergreen and deciduous broad leaved forest,and climax stages.The pattern of species group replacement was that dominance of species groups to be transferred from pioneer species to transition species up to climax species.With natural restoration of degraded karst forest,community height,coverage,dominance were raised gradually,and their range were 0.6～16.9m,0.29～0.79,0.8720～21.8981 cm²·m^-2,respectively.Density was increased in early stages,then decreased.Species number(S),Shannon Wiener index(H '),evenness(J)were increased but ecological dominance(C)was decreased,and their values were 16～50,0.99～4.72,0.77～0.83,0.16～0.05,respectively.Community biomass accumulated gradually from 3.49 t·hm^-2 to 87.45 t·hm^-2 .Percentage of seedlings in total trees increased,and community regeneration strategy was that asexual regeneration in early stages changed into seedling regeneration in later stages.

Key words: Degraded Karst forest, Natural restoration, Species composition and structure of community, Dynamics, Species group