[Species diversity and community structure of forest communities in Lishan Mountain]

Lishan Mountain is belonged to the Zhongtiao Ranges in Southeast Shanxi, and situated between 35 degrees 16'30" - 35 degrees 27'20" N and 111 degrees 51'-- 112 degrees 5'35" E. The climate is cool and arid in winter, but warm and rainy in summer. This paper studied the species diversity and community structure of forest communities there, based on field investigation data and by using diversity, richness and evenness indices. The results showed that the species diversity and evenness of the communities were in the order of Acer davidii + Acer mono > Acer davidii + Carpinus turczaninouii > Quercus liaolugensis > Quercus varibilis > Pinus armandii + Betula albo-sinensis > Pinus tabulaeformis + Quercus glandulifera > Betula platyphylla > Platycladus orientalis + Quercus variabilis > Betula albo-sinensis > Pinus armandii > Platycladus orientalis > Pinus tabulaeformis > Populus davidiana + Betula albo-sinensis. The diversity and richness of shrub layer were higher than those of herb layer and arbor layer, but the evenness of arbor, shrub and herb layers had no significant difference. There were positive correlations (P < 0.05) between Shannon-Wiener index, Hill index, and species richness from 1 000 m to 1 920 m above sea level, but negative correlations (P < 0.05) from 1920 m to the top of the Mountain. The species diversity showed a "mid-altitude bulge" pattern with the change of altitude, and the reason was that the combination of temperature and moisture conditions from 1000 m to 1920 m above sea level was improved, and human disturbance was decreased gradually.