不同植被群落土壤水溶性有机碳的变化特征

目的]对比天然次生林和人工林土壤水溶性有机碳的含量、季节变化特征及与土壤理化性质的相关性,评估不同植被恢复模式对土壤碳库的影响。方法]以浙江省凤阳山不同植被群落为对象,在野外调查和实验测定的基础上,通过相邻样地比较法进行研究。结果]不同植被群落0—60cm土层平均水溶性有机碳含量的大小关系为:35a杉木人工林(0.299 7g/kg)40a常绿阔叶次生林(0.271 7g/kg)35a针阔混交次生林(0.258 6g/kg)40a杉木人工林(0.252 9g/kg)30a柳杉人工林(0.252 8g/kg)30a针阔混交次生林(0.248 0g/kg),相邻样地基本表现为人工林大于天然次生林;不同植被群落土壤水溶性有机碳含量的最小值均出现在夏季。结论]土壤水溶性有机碳含量与土壤总有机碳、全氮、有效磷、速效钾呈极显著或显著正相关,与土壤pH值及容重呈极显著或显著负相关。

Variations of Water-soluble Organic Carbon in Different Vegetation Communities

Objective] To compare soil water-soluble organic carbon(WSOC) content, seasonal variation and its correlation of soil properties between the adjacent natural secondary forest and plantation, for estimating the effect of different vegetation restoration patterns on soil carbon pool. Methods] Taking different vegetation communities of Fengyang Mountain in Zhejiang Province as object, based on the field investigation and experimental measurement, the adjacent sample comparison method was adopt. Results] The average content of WSOC under different vegetation communities followed the order of Cunninghamia lanceolata plantation of 35 years old(0.299 7 g/kg) > evergreen broad-leaved secondary forest of 40 years old(0.271 7 g/kg) > coniferous and broad-leaved mixed secondary forest of 35 years old(0.258 6 g/kg) > Cunninghamia lanceolata plantation of 40 years old(0.252 9 g/kg) > Cryptomeria fortunei plantation of 30 years old(0.252 8 g/kg) > coniferous and broad-leaved mixed secondary forest of 30 years old(0.248 0 g/kg)at 0-60 cm depth. WSOC content of plantation were greater than natural secondary forest in adjacent plots. The minimum value of WSOC in different vegetation communities always appeared in summer. Conclusion] The WSOC content has significant or extremely significant positive correlation with soil total organic carbon, total nitrogen, available phosphorus and available potassium, but has significant or extremely significant negative correlation with soil pH value and bulk density.