神农架不同海拔巴山冷杉林土壤活性有机碳特征

选取土壤微生物量碳(MBC)和水溶性有机碳(WSOC) 2个活性有机碳组分指标，研究神农架巴山冷杉林土壤活性有机碳组分含量的海拔梯度分布特征及其影响因子。结果表明：土壤微生物量碳和水溶性有机碳均随着海拔的升高而增加，随着土层的加深而降低。其中土壤微生物量碳在海拔2 200~3 000 m为0.30~1 22 g/kg，占总有机碳的1.05%~2.09%；水溶性有机碳在不同海拔范围为0.16~0.69 g/kg，占总有机碳的0.57%~1.20%。2个土壤有机碳活性组分均与土壤总有机碳含量、土壤全N含量和土壤湿度呈极显著正相关(P < 0.01)，而与土壤温度呈极显著负相关(P < 0.01)，土壤总有机碳含量是影响土壤活性碳组分含量的决定因素。2个活性有机碳组分之间也呈极显著正相关(P < 0.01)。

Characteristic of Active Soil Organic Carbon of Abies fargesii Forest Along an ElevationGradient in Shennongjia

2 active soil organic carbon fractions of microbial biomass carbon (MBC) and water-soluble organic carbon (WSOC) were selected, and active soil organic carbon fraction content characteristics and its influence factor of Abies fargesii forest in different altitude gradients were analyzed. The results showed the MBC and WSOC content increased with the altitude increase, and decreased with the deepening of soil. The MBC ranges from 0.30 g/kg to 1.22 g/kg at different altitude ranging from 2 200 m to 3 000 m, and the ratio of total organic carbon ranged from 1.05% to 2.09%. The WSOC ranges from 0.16 g/kg to 0.69 g/kg, and the ratio ranges from 0.57% to 1.20%. The 2 active soil carbon fractions content are all showed high positively correlation with total soil organic carbon content, total N content and soil moisture(P < 0.01), while appeared high negatively correlationwith soil temperature(P < 0.01). Total soil organic carbon content is the decisive factor affecting active organic carbon fractions content. And two active soil organic carbon fractions were also appeared high positively correlation.