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不同土地利用下的岩溶作用研究不仅关系到区域岩溶碳汇估算,也关系到岩溶区陆地碳源/汇的准确评估.利用标准溶蚀试片法研究了2个典型岩溶动力系统内3个岩溶泉小流域不同土地利用下的土下溶蚀速率.结果表明,不同土地利用下的土下溶蚀速率差异较明显,耕地、灌丛、次生林、草地、原始林平均值分别为4.02,7.0,40.0,20.0和63.5tkm-2a-1.因此,在进行区域尺度岩溶作用碳汇估算时,除了考虑气候、水文、地质等条件外,还必须考虑土地利用类型的差异.植被的正向演替对岩溶碳汇有显著的促进作用,原始林地土下岩溶作用碳汇量是次生林地的3倍,灌丛的9倍,也就是说,从耕地或灌丛演化到次生林地,由岩溶作用产生的碳汇可提高5.71～7.02tkm-2a-1,若演化到原始林地则达24.86～26.17tkm-2a-1.岩溶区地表森林系统的增汇过程发生的同时,地下也同步发生着类似的增汇过程.
The study of karstification under different land use not only relates to the estimation of regional carbon deposition in karst area but also relates to the accurate assessment of terrestrial carbon source / sink in karst area. Three karst springs in two typical karst dynamical systems Soil erosion rate under different land use in small watershed showed that the difference of soil erosion rate under different land use was obvious, and the average values of cultivated land, shrub, secondary forest, grassland and original forest were 4.02, 7.0, 40.0 and 20.0 And 63.5tkm-2a-1 Therefore, in the estimation of regional scale karst carbon sinks, in addition to considering the climate, hydrology, geology and other conditions, we must also consider the differences in land use types. The positive succession of vegetation on the karst carbon The sinks of subsoil karstic carbon in primary forestland are three times that of secondary forestland and nine times that of shrubland. That is to say, the carbon sink produced by karstification from cultivated land or shrubland to secondary forestland, Can increase 5.71 ~ 7.02tkm-2a-1, and reach 24.86 ~ 26.17tkm-2a-1 if they evolve to the original forestland. Simultaneously, the sink process of surface forest system in karst area occurs simultaneously with similar sinking process .