外来扰动对土壤微生物生物量的影响

Effects of External Disturbances on Soil Microbial Biomass

[目的]探讨外来扰动对土壤微生物生物量碳(SMBC)、生物量氮(SMBN)以及生物量碳氮比(C/N)的影响。[方法]以浙江庆元百山祖自然保护区的土样为研究材料,设置3个梯度的不同外来干扰程度:无人扰动区(W)、无人—外来扰动交汇区(W-Y)和外来扰动区(Y),每个梯度取4个样。[结果]外来扰动会减少微生物生物量碳和生物量碳氮比,增加微生物生物量氮。游人与无人交汇区的SMBC含量最高,最低的是游人区,为1146.66mg/kg,增幅32.86%;游人与无人交汇区的SMBN含量也是最高,最低的也是无人区;生物量碳氮比的比值分别是17.48、9.35、10.71,其中Y处理最低,相比之下W处理和W-Y处理增幅分别达86.94%和14.55%。[结论]外来扰动下不同区域的微生物生物量碳和氮之间的变化趋势不显著,而微生物生物量碳氮比的变化具有显著差异。

[Objective] The aim was to investigate the effects of external distur- bances on soil microbial biomass carbon （SMBC）, biomass nitrogen （SMBN） and biomass carbon to nitrogen ratio （C/N）. [Method] With the soil samples of the Qingyuan Baishanzu Nature Reserve in Zhejiang Province as research materials, three gradients of external disturbances were set up as follows：unmanned distur- bance zone（W）, unmanned and external disturbance joining zone （W-Y） and ex- ternal disturbance zone （Y）, and each gradient took 4 samples. [Results] The external disturbances would reduce the microbial biomass carbon and biomass carbon to nitrogen ratio, and increase the microbial biomass nitrogen. The con- tent of SMBC was the highest in visitors and unmanned joining zone, and was the lowest in the visitors zone for 1 146.66 mg/kg, with an increase of 32.86%. The SMBN content of visitors and unmanned joining zone also was the highest, and the lowest was unmanned zone. The biomass carbon to nitrogen ratios of W, Y and W-Y were 17.48, 9.35 and 10.71, respectively, with Y being the lowest, comparing with W and W-Y had an increase of 86.94% and 14.55%, re- spectively.[Conclusion] The change trend of microbial biomass carbon and nitrogen in different regions was not significant in the external disturbance, but the change of microbial biomass carbon to nitrogen ratio had a significantly different.