亚热带灌丛岩溶区夏季土壤CO_2浓度动态初探

Preliminary study of CO_2 concentration in soil in subtropical karst district of shrub

土壤CO2作为岩溶作用的重要驱动因素受到越来越多学者的关注,本文在对南川市金佛山西坡次生灌丛区连续观测的基础上,对亚热带灌丛岩溶区夏季土壤CO2浓度动态作了详细的研究,初步得出以下结论:(1)土壤CO2随着气温的日变化而呈现明显的日变化,同时对气温的变化有明显的滞后效应。(2)不同土壤深度CO2浓度的大小基本上呈同向变化,但深度对CO2浓度的影响较为复杂。(3)气温和地温的变化和土壤CO2浓度的变化有很大的一致性,温度的变化会引起土壤CO2浓度的较大变化,而植被层的湿度和土壤CO2浓度的变化之间的关系不明显,降水和表层土壤含水量对土壤CO2浓度的贡献较大。(4)土壤CO2明显的驱动着岩溶作用的进行。以上结论的得出对进一步研究土壤CO2对岩溶的驱动作用打下了坚实的基础.

As an important driver factor to karstification,CO 2 in soil has been focused on by more and more scholars. Based on the continuous investigation on the secondly shrub district in west district of Jinfo Mount. of Nanchuan City, Chongqing Municipality, CO 2 concentration dynamic change in soil of subtropical secondly shrub karst district in summer are researched. Some preliminary conclusions are as follows.(1) CO 2 in soil has distinct changes within a day with the change of temperature, and lags behind the change of temperature.(2) The change of CO 2 concentration in soil in different depth is in consistent approximately, but the depth has a complex effect on CO 2 concentration in soil.(3) The concentration of CO 2 changes with the temperature of atmosphere and soil. Temperature change may result in great change of CO 2 concentration in soil. At the same time, the relationship between humid in vegetation and the change of CO 2 concentration in soil is unconspicuous, but precipitation and water content in epi-soil are related closely to CO 2 concentration in soil.(4) Based on the hydrochemical analysis of water in soil, CO 2 in soil is a major driver factor to karstification in research district.All the conclusions above provide a good base for more researchs in the drive function of CO 2 in soil to karstification.