退耕还湖后菜子湖湿地土壤有机质含量变化

以安庆菜子湖区退耕还湖湿地土壤为研究对象,分析退耕还湖后退耕年限、植被恢复状况及人类活动对土壤有机质含量变化的影响。结果表明:植被恢复良好的湿地土壤有机质含量明显高于地表裸露;随着退耕年限的增加,湿地土壤有机质含量呈现上升趋势,退耕20年后湿地表层土壤有机质含量基本达到原始湿地水平,而亚层土壤有机质含量仍显著低于原始湿地;圩内水产养殖湿地土壤有机质含量显著低于圩外水产养殖湿地和原始湿地。结果分析表明退耕后植被恢复状况及水产养殖等人类活动影响退耕后湿地土壤有机质含量变化,减少人类活动干扰有利于退耕后湿地生态自然恢复。

THE CHANGES OF SOIL ORGANIC MATTER CONTENTS IN WETLANDS RECOVERED FROM FARMLANDS IN CAIZI LAKE REGION

Soils in wetlands recovered from farmland were sampled to analyze changes of soil organic matter （SOM） content affected, by recovering years＇, vegetation restoration degree, and human activities. The results showed that SOM content was higher under good vegetation than that in bard wetlands; SOM content increased with recovering years; surface SOM content was no significant difference between wetlands with 20 recovering years and natural wetlands, while subsurface SOM content was lower under wetlands with 20 recovering years than that under natural wetlands; SOM content was lower in wetlands with pond aquaculture than that in wetlands with high net aquaculture. That indicated that vegetation restoration increased SOM and human activities decrease SOM accumulation after returning farmland to lake.