南方山地人工草地群落结构组建及其与环境因子的关系

采用CCA排序技术，定量分离了刈割和放牧下环境、空间、生物和随机因素对亚热带山地人工草地群落结构组建的贡献，分析了不同管理制度下的群落．环境关系．放牧和刈割条件下，与环境因素有关的群落结构变化分别为27．4％、25．9％(其中环境因素独立作用分别为18．9％、19．8％)，空间因素解释的变化分别为32．5％、24．2％，生物及随机因素造成的变化分别为48％、56％．说明放牧削弱了生物学过程(主要是物种相互作用和种子扩散)对群落结构组建的作用，增强了空间因素的影响．空间因素主要是通过与环境因素耦合(改变直接环境的空间分布)对群落结构组建起作用、刈割条件下，群落结构和物种多度沿环境变化呈梯度分布．放牧条件下，环境因素与群落、物种的关系比较复杂，不同干扰程度的群落小斑块向不同方向演替．

Community structure organization and its relation with environmental factors of sown grassland in South China

Contribution of environmental factors,spatial factors,biological and random factors to community structure within a man made grassland in southern terra was partitioned using canonical correspondence analysis.Under mowing and grazing,environmental factors explained (27.4% and 25.9%) variation of community structure.Contribution of spatial factors was 32.5%,24.2%,respectively.Contribution of biological and random factors was 48% and 56%,respectively.Gradient in community structure and species abundance is evident along environmental gradient in mowing grassland.The environment community/species relations were more complex in grazed grassland.Patches under different grazing intensity develop toward different directions.