红松人工林植被恢复对土壤活性有机碳组分影响的时效性

Effects of Vegetation Restoration of Pinus koraiensis Plantation on Timeliness of Soil Active Organic Carbon Structure

以小兴安岭阔叶红松林皆伐迹地上不同时期营造的红松人工林(林龄分别为26、37、49和62年生,阔叶红松原始林为对照)为研究对象,通过对0~20cm土层范围内土壤总有机碳、总氮、水解氮、可溶性有机碳、微生物量碳、易氧化有机碳、颗粒有机碳和轻组有机碳质量分数的测定与分析,研究了红松人工林植被恢复对土壤活性有机碳组分动态影响。结果表明:所研究的不同恢复时段红松人工林土壤总有机碳、总氮和水解氮质量分数表现出随着人工恢复的时间而增加的趋势,62年生红松人工林土壤全氮质量分数与红松原始林之间无显著性差异,且下层土壤总有机碳质量分数显著高于红松原始林(p<0.05),表明人工植被恢复超过60a时土壤总有机碳和全氮质量分数即可得到有效恢复并接近红松原始林水平;土壤颗粒有机碳质量分数与总有机碳的关系极为显著(p<0.01),表现出虽然人工林植被土壤颗粒有机碳质量分数显著低于红松原始林(p<0.05),但随植被恢复时间的增加而显著增加的一致性规律,可以认为土壤颗粒有机碳质量分数可作为定量表征红松人工林植被恢复引起的土壤活性有机碳变化的敏感性指标。

To understand the dynamic effect on soil active organic carbon fractions in vegetation-restored Pinus koraiensis plantations,0-20 cm depth soils were collected from four stand age of P.koraiensis plantations (26,37,49 and 62 a),respectively,which cultured and afforested in mixed broad-leaved P.koraiensis clear felling blank,and a virgin broad-leaved P.koraiensis forest (as a control) in Xiaoxing'an Mountains.The contents of soil total organic carbon,total nitrogen,hydrolysable nitrogen,soluble organic carbon,microbial biomass carbon,easily oxidized organic carbon,particulate organic carbon and light organic carbon were determined and analyzed.With the increasing years of artificial recovery,the total organic carbon,total nitrogen and hydrolyzed nitrogen contents of P.koraiensis plantations in different restoration periods represented an increasing trend.The difference of soil total nitrogen content between 62-a P.koraiensis plantation and virgin P.koraiensis was not significant.The total organic carbon content of 62-a P.koraiensis plantation in lower soil layer was significantly higher than virgin broad-leaved P.koraiensis (p <0.05).These results indicated that the total organic carbon and total nitrogen in the soil could be approximately restored to the virgin P.koraiensis when the artificial vegetation recovered over 60 a.A highly significant correlation ( p <0.01) between soil organic carbon and total organic carbon implied that the particulate organic carbon content raised with the increasing vegetation restoration years though the particulate organic carbon content in P.koraiensis plantation obviously lower than virgin Pinus koraiensis (p <0.05).The results suggested that particulate organic carbon can be considered as a sensitive indicator,which is quantitative description of the active organic carbon variation caused by vegetation-restored P.koraiensis plantations.