Short-term Effects of Pruning on Biodiversity of Picea asperata Mast. by Artificial Plantation with Different Ages in Sub-alpine Regions of Western Sichuan,China

Studies were made of the total biomass,bio-diversity of shrub layer and grass layer from 20 years old,30 years old and 40 years old artificial forest of Picea asperata Mast.under different pruning intensity modes (X1,X2 and X3 respectively meaning cutting off 0 m branch,1m branch and 2 m branch above the ground).And effects of pruning on biomass and biodiversity of shrub and grass under the artificial forest were analyzed through representative sampling and harvesting.The result showed that pruning had a kind of effect on shrubs and grasses under forest in short-term period.The bio-diversity of shrub layer and grass layer under forest were more sensitive than the biomass of them.Shannon-Weiner index of shrub layer of 20 years old and 30 years old artificial forest and Simpson index of 30 years old artificial forest increased significantly after pruning.X1 had a stronger effect on promoting bio-diversity of shrub layer than X2.