An estimation of soil microbial biomass as nutrient sink in forest soils.

两种方法已被应用于了解土壤微生物生物量在森林土壤中的作用。通过对土壤微生物生物量测定方法的综述，证明了氯仿熏蒸法适用于酸性土壤，适合于森林土壤微生物生物量的研究。森林在1994年被砍伐和烧毁。建立了次生林、皆伐和火烧迹地3个试验样地，比较了皆伐和火烧迹地的效果。土壤有机层中微生物生物量碳为2 ~ 12 mg g ~（-1），表层土壤中微生物生物量碳为0.2 ~ 0.6 mg g ~（-1）。夏季各小区土壤微生物生物量均呈上升趋势。森林皆伐减少了有机层的生物量，矿物土壤的生物量略有减少。采伐迹地后的火烧破坏了表层土壤的有机质层，降低了土壤微生物生物量，尤其是在坡底，在那里观察到强烈的火烧。火烧对土壤微生物生物量的影响在火烧后14个月仍存在，说明火烧迹地土壤有机质的分解受到抑制，当土壤受到皆伐和/或火烧迹地干扰时，测定森林土壤微生物生物量可能比测定土壤有机质含量更敏感。

Two approach have been applied for understanding the role of soil microbial biomass in forest soils. A literature review of recent papers on estimation of soil microbial biomass proved that chloroform fumigation extraction method, which is applicable for acidic soils, is suitable for the soil microbial biomass study in forest soils.Seasonal changes in soil microbial biomass have been observed in a mixed secondary forest of pine and oak. The forest have been cut and burned in 1994. Three study plots have been established, secondary forest, clear-cut, and slash-burned, and the effects of clear-cutting and slash-burning were compared. Microbial biomass carbon in the organic layr was 2 to 12 mg g-1, and 0.2 to 0.6 mg g-1 in surface soil. Soil microbial biomass increased in summer in every plots. Clear-cutting of the forest reduced biomass in organic layr and slightly reduced in mineral soil. Burning after slashing eliminated soil organic layr and reduced soil microbial biomass in surface soils, especially in bottom of the slope, where intensive burning was observed. Effect of burning for the soil microbial biomass existed 14 months after burning, and it suggests that decomposition of organic matter in slash-burned area will be inhibited.The measurement of soil microbial biomass in forest soils may be more sensitive index than soil organic matter contents when the soil has been disturbed by clear-cutting and/or slash-burning.