【摘要】 林隙是森林生态系统的典型干扰之一,林隙结构改变了森林局部区域的生境条件。以温带成熟林中的倒木林隙为观测对象,通过野外采集土壤样品,在生长季节中研究了林隙与林下表层土壤活性碳氮库的月际动态。研究结果显示,林隙环境中土壤湿度和容重显著高于林下;虽然林隙土壤溶解性有机碳(DOC)含量和土壤铵态氮含量显著低于林下,但是林隙土壤硝态氮含量显著高于林下。林隙和林下的土壤微生物量碳(SMBC)含量无显著差异,而林隙的土壤微生物量氮(SMBN)显著低于林下。相关分析结果显示,土壤微生物碳氮库与土壤湿度和容重的相关性显著;在土壤活性碳氮库间,林隙土壤SMBC和SMBN的主要相关因素是土壤DOC,而在林下则是土壤硝态氮。同时还综合分析了林隙干扰对森林表层土壤活性碳氮库的影响,并探讨了林隙土壤活性碳氮库的维持机制。更多还原

【Abstract】 Forest gap is one of typical disturbances in forest ecosystem, and changes forest habitats in microcosm. In current study, we carried out a field observation involved forest tree-fall gap in old-growth temperature forest by taking soil samples, and monthly dynamics of soil active carbon and nitrogen pools in forest gap and under canopy were investigated during growth season. The results indicate that soil moisture and bulk destiny are significantly higher in forest gap than that in under canopy. Although soil dissolved organic carbon(DOC) and soil ammonium are higher in under canopy than those in forest gap, soil nitrate is higher in forest gap than that in under canopy. Soil microbial biomass C(SMBC) has no significant difference between forest gap and under canopy, but Soil microbial biomass N(SMBN) is significantly higher in under canopy than that in forest gap. Based on correlation analysis, soil microbial C and N pools have significant correlation with soil moisture and bulk destiny. Among soil active C and N pools, soil DOC is the major related factor of SMBC and SMBN in forest gap, but soil nitrate exert under canopy. Moreover, the effects of gap disturbance on active C and N pools of forest topsoil were analyzed comprehensively, and the maintenance mechanisms of soil active C and N pools in forest gap were discussed.更多还原