洞庭湖湿地土壤有机质空间分布及其相关性研究

以洞庭湖湿地的泥沙滩地、湖草滩地、芦苇滩地和集成垸人工杨树林为研究对象。研究了不同湿地类型的土壤有机质含量的统计学特性、土壤有机质的水平分布、垂直分布特征以及其与pH值、土壤水分和容重等指标的相关性。结果表明,4类湿地类型土壤有机质差异显著;湿地表层土壤有机质的水平分异为：湖草滩地（33.04±10.86）g/kg〉芦苇滩地（23.23±4.78）g/kg〉杨树林地（16.92±3.44）g/kg〉泥沙滩地（4.60±0.59）g/kg,除泥沙滩地外,其他3类土壤有机质含量和人为干扰因素呈负相关关系;土壤有机质的垂直分异为：除泥沙滩地外,湖草滩地、芦苇滩地和杨树林地的土壤有机质含量都是从上到下依次递减;湿地土壤有机质与pH值呈显著负相关关系（0.05水平）,Pearson相关系数为-0.594;有机质和土壤水分呈极显著的正相关关系（0.01水平）,Pearson相关系数为0.830;土壤有机质与容重呈极显著的指数负相关关系（P〈0.01）,回归方程为：Y=367.308e-2.462X（R=-0.885,N=43）。

Study on Spatial Distribution and Correlation of Soil Organic Matter in Wetland of Dongting Lake Floodplain

The statistics characteristics,horizontal distribution and vertical distribution of soil organic matter and correlation with PH ,soil water content and bulk density in 4 types wetlands of Dongting Lake Floodplain were studied. Results showed that there were significant differences of soil organic matter in 4 type wetlands： the horizontal distribution of soil organic matter was Carexspp-dominated floodplain（33.04 ± 10.86）g/kg Phragmites-dominated floodplain（23.23 ± 4.78）g/kg the man made populus-dominated floodplain（16.92 ± 3.44）g/kg mud and sand-dominated floodplain （4.6 ± 0.59）g/kg, and there were negative relationship with human disturbances except for the mud and sand-dominated floodplain, the vertical variation of soil organic matter was reduced with increasing depth from 0 to 60cm except for the mud and sand-dominated floodplain,there were negative relationship （R=-0.594＊,P 0.05）between soil organic matter and PH, a significant positive relationship （R=0.830＊＊,P 0.01） between soil organic matter and soil water content, and a significant negative index relationship （P 0.01） between soil organic matter and bulk density,the regression equation was Y=367.308e-2.462X （R=-0.885, N=43）.