Community Characteristic and Population Structure of Ormosia saxatilis in Guizhou Province

WANG Mao-shi;YUAN Cong-jun;AN Ming-tai;YAN Ling-bin;LI He;YU De-hui;Forestry Survey Design Corporation of Guizhou Province;College of Forestry,Guizhou University;Guizhou Academy of Forestry;National Nature Reserve of Leigong Mountain;

different disturbance density;;species diversity;;population structure;;natural regeneration;;Ormosia saxatilis

Population structure and community characteristics of Ormosia saxatilis under different disturbance densities was studies by using classical community sampling approach,and the results shows that:(1) The species diversity of tree layers in the community is rich. The diversity index( SW) is 2. 66 ~ 3. 26,the ecological dominance( ED) is 0. 11 ~ 0. 17,and there is no significant difference between different community samples;(2) Even Ormosia saxatilis could become subdominant species or co-dominant species of some local communities,but such phenomena is few and it is usually at a disadvantage position in the whole tree layer community;(3) The grade index of Ormosia saxatilis population size are different under different disturbance densities,the SDI in Bijia Mountain is a negative value(- 0. 003 7) with continuous population,and SDI in Qianling Mountain is positive(0. 001 6) with discrete population;(4) The age structure of the regeneration layer in the communities is an inverted pyramid type. The number of I-grade seedlings is was small,and the most are saplings from II to IV,and natural regeneration of Ormosia saxatilis is not obvious.