人造林窗对粗枝云杉人工林土壤微生物量的影响

Efects of Man-made Forest Gaps on Soil Microbial Biomass in Picea asperata Plantation

通过对川西亚高山云杉低效林不同大小林窗(面积50 m2、100 m2、150 m2)改造,以未处理作为对照,采用氯仿熏蒸浸提法研究了林窗改造对土壤微生物生物量碳、氮含量及其垂直分布特征的影响。结果表明:通过林窗改造,林下土壤微生物量碳、氮具有显著提升,其中,林窗面积越大,提升效果越显著。各土层土壤微生物量碳、氮含量均表现为:150 m2(L3)>100 m2(L2)>50 m2(L1)>对照(CK);3种大小面积林窗和对照土壤微生物量碳、氮含量随着土层深度的增加而降低,均表现为上层(0~5 cm)>中层(5 cm^10 cm)>下层(10 cm^15 cm);且林窗改造降低了土壤微生物量碳、氮的表层富集特性,林窗面积越大,上层土壤微生物量碳、氮所占比例越低。

In this paper,three kinds of forest gaps with different area （ LI ：50 m^2, L2 ： 100 m^2, L3 ： 150 m^2） were set in a 50-years old Picea asperata plantation, and at the same time, the forest without cutting was set as control （CK）. The soil was sampled in different soil layers（0 -5 cm,5 cm -10 cm,10 cm - 15 cm）,and then was determined by adopting chloroform fumigation, aiming to study the effect of forest gap improvement on carbon and nitrogen content and vertical distribution of soil microbial biomass. The results showed that the forest gaps had significantly increased the contents of soil microbial biomass carbon （SMBC） and soil microbial biomass nitrogen （SMBN）, and the bigger the gap＇s area was, the more the increase effect was. The contents of SMBC and SMBN in each soil layer was L3 〉 L2 〉 L- 〉 CK. In the three kind of gaps and CK, the contents of SMBC and SMBN decrease with the increase of soil depth, but in the 0 - 5 cm layer, the bigger the gap＇s area was, the proportion of the content SMBC and SMBN would become less.