Effects of thinning intensity on diversity of undergrowth vegetation and regeneration in artifical spruce forest

In order to explore the effects of pre-and post-thinning intensity on undergrowth vegetation and regeneration in artificial spruce (Picea asperata) forest,species number,coverage,height of vegetation and seedling were investigated.Species richness,indices including Shannon-Wiener,Simpson and Pielou were analyzed to study plant diversity in this study.The results showed that the reserve trees growth with thinning were better than those control ones (without thinning) and species number of undergrowth vegetation with thinning plots increased significantly.With thinning intensity increased,the species richness,biomass and coverage of undergrowth vegetation also increased,and the most heavy thinned stands (450 stem·ha-1) showed the highest value of each index.The density,species richness,and height of seedling increased with thinning intensity.In heavy thinning intensity plots,tree seedling with all size classes distributed which did not observed in other plots.There was significant positive correlation between light and seedling diversity,density and richness,while the thin layer may have negative effects on them in thinning intensity plots.In this study,herbaceous coverage was observed to be the important factor in seedling richness and seedling density.