Species diversity of forest communities in southern Taihang Mountains,Shanxi

The species diversity and its relations of forest communities to the environment in southern Taihang Mountains were analyzed in terms of diversity index,abundance index and evenness index and the resuits revealed that （1） the species-diveristy indexes of the three vegetation types increase in the order of deciduous broadleaf forest,temperate coniferous and broadleaf mixed forest and temperate coniferous forest. （2） In various formations of deciduous broadleaf forest ,the species-diversity indexes increase in the order of Form. Toxicodendron vernici fluum ＋ Rhus potaninii , Form. Carpinus turczaninowii ＋ Acer davidii , Form. Pteroceltis tatarinowii, Quercus liaotungensis, Form. Quercus variabilis, Form. Betula platyphylla, Form. 13etula albo-sinensis and Form. Populus davidiana ＋ 13etula albo-sinensis. （3） Various formations of temperate coniferous forest, the species-diversity indexes increase in the order of Form. Taxus chinensis var. mairei,Form. Pinus tabulaeforrnis,Form. Pinus bungeana and Form. Platycladus orientalis. （4） In forest communities,the species abundance indexes generally tend to increase in the order of herb stratum, shrub stratum and arbor stratum,and the species diversity indexes generally tend to increase in the order of shrub stratum,arbor stratum and herb stratum. In various communities, the species evenness indexes in shrub stratum are higher than those in arbor stratum and herb stratum,and the species evenness indexes of herb stratum and arbor stratum do not differ significantly. （5） In various communities ,the species diversity indexes appear to vary with the elevation above sea level in a single-peak curve,i, e. ,high with medium elevation and low with low and high elevations above sea level ,and this is mainly because there is a favorable water and warmth combination at medium elevation （about 1 500 i/a） above sea level and low human disturbance.