温带阔叶红松林表层土壤活性碳、氮库的季节动态

以长白山温带阔叶红松林为观测对象,在植被生长季节对森林表层土壤进行连续性采样分析,以研究森林土壤活性碳、氮库的季节性变化特征及其影响因素。结果表明,不同季节土壤水溶性有机碳和硝态氮含量从高到低依次为春季、夏季和秋季,其变化范围分别为48～80和0.68～2.30μg.g-1。不同季节土壤水浸提溶液的特征吸光系数ASUVA,254和土壤铵态氮含量均表现为夏季高于春季和秋季,其变化范围分别为3.19～3.94 L.mg-1.m-1和6.1～12.0μg.g-1。在小时间尺度上,土壤活性碳、氮库对土壤含水量变化具有敏感性。水分条件和植物根系活动是影响表层土壤活性碳、氮库动态变化的主要因素,土壤微生物活动起调节作用。

Seasonal Dynamics of Soil Active Carbon and Nitrogen Pools in Surface Soil of Temperate Broad-Leaved and Korean Pine Mixed Forest

To investigate seasonal variations of soil active carbon and nitrogen pools in forest soils and their affecting factors,soil samples were collected for analysis from the surface soil layer of a temperate broad-leaved and Korean pine mixed forest in the Changbai Mountains,once every 1-3 days during the vegetation growing season.Results show that the contents of soil water-soluble organic carbon and nitrate-N varied seasonally in the range of 48-80 and 0.68-2.30 μg·g-1,respectively,showing the same decreasing order of spring,summer,and autumn.Both the specific ultra-violet absorbance（ASUVA,254） of soil water extract and the content of ammonium-N were higher in summer than in spring or autumn,varying in the range of 3.19-3.94 L·mg-1· m-1 and 6.1-12.0 μg·g-1,respectively.In small time scales,soil active carbon and nitrogen pools were sensitive to variation of soil water content.The correlation analysis suggests that soil water regime and activities of plant root systems were the major factors affecting the seasonal dynamics of soil active carbon and nitrogen pools,and activities of soil microbial organisms also played a regulatory role.