武夷山不同海拔梯度土壤微生物生物量、微生物呼吸及其商值(qMB，qCO2)

Soil microbial biomass,respiration,and metabolic quotient along an altitudinal gradient in Wuyi Mountain of southeastern China

土壤微生物生物量、土壤微生物呼吸及微生物商值(微生物商(qMB)、微生物呼吸商(qCO2))是土壤质量的敏感性指标。本文对武夷山不同海拔梯度具有代表性的中亚热带常绿阔叶林、针叶林、亚高山矮林以及高山草甸土壤微生物生物量、土壤微生物呼吸及其qMB、qCO2进行了研究。结果表明:土壤微生物生物量、土壤微生物呼吸均随海拔梯度的升高而加大,随土层深度的加深而降低,qMB、qCO2没有表现出随海拔变化的规律,qMB的最大值(2.23%±0.28%)出现在高山草甸0～10cm土层的土壤,最小值(0.51%±0.09%)为常绿阔叶林25～40cm土层土壤,针叶林的值大于亚高山矮林;qCO2的最大值(5.88%±0.94%)为针叶林25～40cm土层土壤,最小值(1.38%±0.09%)为高山草甸0～10cm土层的土壤。在同一林分,qMB值随土层加深而减小,qCO2值在亚高山矮林和高山草甸无此规律。土壤微生物生物量、微生物呼吸及其qMB、qCO2与土壤总有机碳、全氮、全磷具有显著的线性相关关系(P<0.05),可用来评价土壤质量。

Soil microbial biomass, respiration, and metabolic quotient are the sensitive indicators of soil quality. The measurement of these variables in evergreen broadleaf forest （ EBF）, coniferous forest （CF） , dwarf forest （DF）, and alpine meadow （AM） along an altitudinal gradient in the natural reserve area in Wuyi Mountain of Fujian Province showed that soil microbial biomass and respiration increased with increasing altitude but decreased with soil depth, while soil microbial metabolic quotient qMB and qCO2 had no definite variation pattern along the altitudinal gradient. The qMB was the highest （2.23% ±0. 28% ） in 0-10 em soil layer in AM and the lowest （0. 51% ±0. 09% ） in 25-40 cm soil layer in EBF, and CF had a higher qMB than DF. The qCO2 was the highest （5.88% ±0. 94% ） in 25-40 cm soil layer in CF and the lowest （1.38% ±0. 09% ） in 0-10 cm soil layer in AM. In the same stands, qMB decreased with increasing soil depth, while qCO2 was not. Soil microbial biomass, respiration, qMB, and qCO2 had significant linear correlations with soil total organic carbon, total nitrogen, and total phosphorous （P 〈 0. 05 ）, being possible to be used as the good indicators to assess soil quality.