Community Characteristics of 3 Tree Plantations in Tropical Yunnan

Community characteristics of 3 mature plantations are investigated using plot sampling method in the Puwen experimental forest farm,in comparison with the zonal vegetation of montane rainforest and degraded secondary forest. The results show that:( 1) there are 43 species of vascular plants in Pinus caribaea plantation,32 species in Parashorea chinensis + Pometia tomentosa mixed plantation and 29 species in Mytilaria laosensis + Choerospondias axillaris mixed plantation;( 2) Shanon-Weiner index of tree layer of three plantations varies from 1. 82 to 2. 71,while that of shrub layer and herb layer is 1. 52 ~ 1. 78 and 2. 15 ~ 2. 69,the highest diversity takes place in P. caribaea plantation;( 3) the vertical structure of three communities can be divided into tree layer Ⅰ and Ⅱ,shrub layer and herb layer clearly;( 4) species richness and diversity index of three plantation communities are all lower than that of zonal vegetation and degraded secondary forest,while vertical structure are more complex than the degraded secondary forest,but simpler than the montane rainforest.