衡阳紫色土丘陵坡地土壤理化与植物群落特征

为了对衡阳紫色土丘陵坡地的土壤理化与植物群落特征进行分析，先用“空间代替时间”方法，选择3类典型样地，分别代表群落演替进程中3个不同的阶段，再用野外样地调查和室内分析法研究了衡阳盆地紫色土丘陵坡地自然恢复演替进程中主要植物群落不同演替阶段的植被根系空间变化和土壤环境因子间的关系。结果表明：（1）土壤理化特征为阴坡优于阳坡，下坡优于中坡，中坡优于上坡；（2）在阴坡与阳坡的上坡、中坡与下坡每一生境对应不同的群落类型，且植被盖度与植物多样性指数的大小顺序均为：阴坡下坡＞阳坡下坡＞阴坡中坡＞阳坡中坡＞阴坡上坡＞阳坡上坡；（3）不同生境条件与植被盖度关系符合方程Y=10.234X-4.5867(R2=0.8932)；（4）各生境的物种丰富度(S)、Simpson指数(D)与Shannon-wiener指数(H)三者的关系符合方程：S=-0.0579+0.2367D+0.3579H，r=0.9147(P＜0.01)；（5）不同植物群落的相似性指数上下波动，变化趋势符合方程Y=0.1268X+0.087(R2=0.8699)。这将丰富该地区植被生态学与恢复生态学的内容，为衡阳盆地紫色土丘陵坡地生态系统的植被与重建提供一定的理论依据。

Soil Physiochemical and Vegetation Phytocoenological Characteristic of Sloping-land with Purple Soils in Hengyang

In order to analyze the soil physiochemical and vegetation phytocoenological characteristic of sloping-land with purple soils in Hengyang.Firstly,by using the space series to replace time courses,3 typical sample plots standing for 3 different successive stages were chosen and then field surveys and experimental analysis were used to detect the relationship between spatial changes of vegetation roots and soil environmental factors under different succession process of the main plant communities in natural restoration succession process in sloping-land with purple soils in Hengyang.The results showed that：（1） the soil physiochemical characteristic were that the north-facing slope was better than the south-facing slope,the down-slope was the best,the middle-slope was the better and the upper-slope was the worst;（2） There was a different plant community type in each position,such as the upper-slope,middle-slope and down-slope of the north-facing slope and south-facing slope and the sequence of the coverage degree and the bio-diversity indexes were：the down-slope on north-facing slopethe down-slope on south-facing slopethe middle-slope on north-facing slopethe middle-slope on south-facing slopethe upper-slope on north-facing slopethe upper-slope onsouth-facing slope;（3） The relation between the each environmental condition and the vegetation coverage degree corresponded to the equality：Y=10.234X-4.5867（R2=0.8932）;（4） The relation among the richness（S）,Simpson index（D） and Shannon-wiener index（H） in each environmental condition corresponded to the equality：S=-0.0579 ＋ 0.2367D ＋ 0.3579H,r=0.9147（P0.01）;（5） The likeness index of different plant communities fluctuated up and down,and the trend of change matched the equality：Y=0.1268X＋0.087（R2=0.8699）.This study will to some degree enrich and broaden the vegetation ecology and restoration ecology of this area and provide theoretical basis for the vegetation recovery and reconstruction of ecosystem in sloping-land with purple soils in Hengyang.