暖温带落叶阔叶林的物种多样性特征

SPECIES DIVERSITY CHARACTERISTICS OF DECIDUOUS FORESTS IN THE WARM TEMPERATE ZONE OF NORTH CHINA

本文从区域、群落结构和动态出发研究了分布于华北地区的主要落叶阔叶林的物种多样性指数特征，结论如下：（１）随着从北到南纬度的不断降低，落叶阔叶林的物种多样性指数不断增加，优势度指数不断减小．其中，乔木层和灌木层的物种多样性指数均遵循上述规律。草本层的物种多样性指数增加后又降低，优势度指数减低后又增加．（２）海拔１２００ｍ以下，物种多样性指数随海拔增加而增加．海拔１２００ｍ以上则随海拔增加而减小。（３）乔木层同灌木层间的物种多样性指数具最大的相关注。（４）物种多样性指数从演替初期到中期不断地增加，到演替后期开始下降。

he species diversity characteristics of main deciduous broadleaved forests distributed innorth China were studied on a regional,community structure and dynamic basis。The resultsshow that the deciduous broadleaved forests have increasing species diversity indices and de-creasing dominance indices with the decreasing latitude from the north to the south.Both thearbor and shrub layers of the forests follow the above regularity on species diversity indiceswhile the herb layers have their species diversity indices increased first then decreased andtheir dominance indices decreased first then increased.The species diversity indices increaseas the altitude increases below 1200m above sea level while decreasing as the altitude increas-es over 1200m above sea level. The species diversity indices of the arbor layers are most cor-relative to those of the shrub layers。The species diversity indices are increasing from the ini-tial stage to the middle stage of succession and then decreasing in the climax stage。