衡阳紫色土丘陵坡地植物群落根系与土壤理化特征

为了对衡阳紫色土丘陵坡地自然恢复演替进程中主要植物群落植被根系与土壤理化特征的变化进行研究。先用“空间代替时间”的方法，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格局和土壤环境因子间的关系。结果表明：（1）随着植物群落演替进行，不同阶段植物群落的生态特征，土壤的理化性质等产生相应的变化，演替初期、演替中期与演替后期0~15 cm土层的根系量与土量的比例分别为0.18、0.15、0.12；（2）随着植物群落演替进行，植物根系的空间分布格局会发生相应的变化，不同的演替阶段土壤根系的基质量的大小顺序为：演替初期＜演替中期＜演替后期，0~15 cm土层的根土比的变化规律为：演替初期＞演替中期＞演替后期；（3）随着植物群落演替进行，植物根系(0~60 cm)的空间分布格局、根土比、土壤容重与土壤含水量会发生相应的变化，且它们与土壤中氮的含量存在一定的相关性。

Vegetation Roots and Soil Physical and Chemical Characteristic in Sloping-land with Purple Soils in Hengyang

In order to analyze the change of the vegetation roots and soil physical and chemical characteristic of main plant communities in natural restoration succession process in sloping-land with purple soils in Hengyang by the quantitative analysis method.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 pattern 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） there were corresponding changes in the ecological characteristics of plant communities and the soil physical and chemical characteristics with the succession process,in the succession initial stage,the succession middle stage,the succession end stage the ratio root to soil of 0-15 cm soil layer was 0.18,0.15 and 0.12,respectively;（2） The spatial distribution pattern of roots changed with the succession process,the order of the soil quantity attached to roots was：the succession initial stagethe succession middle stagethe succession end stage,and the order of the ratio of root to soil of 0-15 cm was：the succession initial stagethe succession middle stage the succession end stage;（3） There were corresponding changes in the spatial distribution pattern of plant roots（0-60 cm）,the ratio of the roots to soil attached to them,the soil bulk density,the soil water contents with the succession process,and there was a certain corresponding relationship with the N content in soil.