高寒退化湿地土壤有机碳及微量元素变化特征

Characteristics of Soil Organic Carbon and Trace Element Changes in Alpine Degraded Wetlands

摘要: 受全球气候变化影响，高寒湿地面积萎缩，湿地退化问题凸显，对湿地土壤生态系统生物地球化学循环产生了重要影响。目前关于高寒湿地退化对土壤养分和微量元素的影响还不十分清楚。本研究对比了两种高寒退化湿地土壤养分和微量元素含量的差异。结果表明，湿地退化对表层土壤有机碳、全氮和微量元素含量均有明显影响。与轻度退化湿地相比，重度退化湿地土壤有机碳和全氮含量分别下降了26.22%和31.16%，说明湿地退化对土壤养分含量的影响很大。高寒湿地由轻度退化向重度退化阶段转变后，土壤铁含量下降了14.80%，锰含量下降11.16%。重度退化湿地土壤铜和锌含量下降程度基本相当，分别为7.74%和7.78%。该结果表明，高寒湿地退化对土壤微量元素的影响也十分明显。重度退化湿地土壤养分和微量元素含量下降的原因，可能与湿地退化后地表植被覆盖度降低，凋落物输入减少以及土壤质地的改变有关。

Abstract: Affected by global climate change, the area of alpine wetlands has shrunk, and the issue of wetland degradation has become prominent, significantly impacting the biogeochemical cycles of wetland soil ecosystems. Currently, the effects of alpine wetland degradation on soil nutrients and trace elements are not fully understood. This study compared the differences in soil nutrients and trace element content between two types of degraded alpine wetlands. The results indicate that wetland degradation has a noticeable impact on the organic carbon, total nitrogen, and trace element content in the topsoil. Compared to lightly degraded wetlands, the soil organic carbon and total nitrogen content in heavily degraded wetlands decreased by 26.22% and 31.16%, respectively, indicating a substantial impact of wetland degradation on soil nutrient levels. After the transition from mild to severe degradation in alpine wetlands, the soil iron content decreased by 14.80%, and manganese content decreased by 11.16%. The reduction in copper and zinc content in severely degraded wetland soils was roughly equivalent, at 7.74% and 7.78%, respectively. These findings indicate that the degradation of alpine wetlands also significantly impacts soil trace elements. The decline in soil nutrients and trace element content in severely degraded wetlands may be related to the reduced surface vegetation coverage, decreased input of litter, and changes in soil texture following wetland degradation.