云南哀牢山湿性常绿阔叶林土壤碳分布特征

通过调查亚热带森林生态系统中各类属性土壤碳在2种不同类型土壤剖面中的分布规律,分析和探讨原生土和淤积土在森林土壤碳循环过程中发挥的重要作用。本研究地点位于云南省哀牢山亚热带中山湿性常绿阔叶原生林生态系统,以海拔高度较高的上游森林原生土和海拔高度较低的下游灌草淤积土为采样点,沿着土壤剖面分层取样,重点研究土壤剖面根层(0~45 cm)土壤中全碳、活性有机碳、微生物量碳、可溶性碳和水溶性碳的垂直分布规律。研究结果表明：本研究过程中所调查的5类不同属性土壤碳在两种不同类型土壤剖面中均呈衰减指数式分布。土壤全碳、活性有机碳和水溶性碳在淤积土中的平均含量均显著高于原生土;土壤微生物量碳在2种类型土壤剖面中的平均含量差异不显著;而土壤可溶性碳在淤积土中的含量显著低于原生土,说明在哀牢山亚热带中山湿性常绿阔叶原生林生态系统中原生土和淤积土在储存不同属性土壤碳和碳循环方面发挥着不同作用。本研究结果充分证明不同属性土壤碳在同一亚热带森林生态系统不同类型土壤剖面中虽然垂直分布规律一致,但是平均储量存在着明显的空间异质性,这为全球热带和亚热带森林生态系统中土壤碳库不同属性土壤碳的估算和不同类型土壤碳循环的研究提供新的理论依据和研究方向。

Distributional Characteristics of Soil Carbon in Moist Evergreen Broad-leaved Forest in Ailao Mountains of Yunnan Province

By investigating the distributional pattern of soil carbon with various properties in two types of soil profile in a subtropical forest ecosystem, the primary soil and warp soil were analyzed and explored for their important roles in the process of soil carbon cycle. We conducted the study in a subtropical mountainous moist evergreen broad-leaved forest in the Ailao Mountains of Yunnan Province, took the primary soil in the forest area with high altitude and the warp soil in the shrubby-meadow area with low altitude as sampling sites, collected soil samples in different soil layers along the two types of soil profile, and focused on the vertical distribution pattern of soil carbon with various properties including soil total organic carbon, labile organic carbon, microbial biomass carbon, dissolved carbon and water dissolved carbon in the soil layers with most plant roots (0-45 cm). The results show that the concentrations of all determined soil carbon with different properties decrease exponentially along the two types of soil profile. The concentrations of soil total organic carbon, labile organic carbon and water dissolved carbon in the warp soil are statistically higher than those in the primary soil; the concentration of soil microbial biomass carbon is not statistically different between the two types of soil; and the concentration of dissolved carbon in the warp soil is significantly lower than that in the primary soil, indicating that the primary and warp soil play different roles in storing and circulating soil carbon with different properties in the subtropical mountainous moist evergreen broad-leaved forest ecosystem in the Ailao Mountains. The results adequately demonstrate that although the vertical distribution pattern of soil carbon with various properties in different soil profiles of the same subtropical forest ecosystem is consistent, the average storage has obvious spatial heterogeneity. The paper could provide a new theoretical basis and research direction for the estimation of soil carbon with different properties in the global tropical and subtropical forest ecosystems and the study on soil carbon cycle in different types of soil profile.