关键词: 细根(草根), 微生物量碳, 水溶性有机碳, 易氧化有机碳, 总有机碳

Abstract:

In this study, the effects of fine root (grass root) decomposition to the soil active organic carbon were investigated in a laboratory microcosm under 10, 20 and 30 ℃. The roots were mixed with the soil in the following four treatments: mixture of birch (Betula luminifera) roots and grass (Hemarthria compressa) roots (treatment 1), birch (Betula luminifera) roots (treatment 2), grass (Hemarthria compressa) roots (treatment 3), cedar (Crytomeria fortunei) roots (treatment 4) and no roots (CK). The results showed that fine root source, incubation time and incubation temperature all influenced soil microbial biomass carbon (SMBC),water soluble organic carbon (WSOC),readily oxidized carbon (ROC),total organic carbon (TOC). After 120 d, the contents of SMBC,WSOC,ROC,and TOC in the treatments were higher than those in CK (P＜0.05). The contents of SMBC,WSOC,ROC,and TOC in treatment 1 were higher than those in the other treatments in 60 or 120 d. The effect of incubation temperature on MBC and WSOC in four treatments was ranked in an order as the following, 30 ℃＞20 ℃＞10 ℃, while the effect on ROC and TOC was in an order of 10 ℃＞20 ℃＞30 ℃(P＜0.05).

Key words: fine root(grass root), soil microbial biomass carbon, water-soluble organic carbon, readily oxidized organic carbon, total organic carbon