桂林毛村地下河流域岩溶关键带碳循环研究

Study on Carbon Cycle of Karst Critical Zone in Maocun Subterranean River Basin of Guilin

关键词:  岩溶关键带  毛村地下河  碳循环  植被-土壤-岩石-地下水连续体

Key words:  karst critical zone  Maocun subterranean river  carbon cycle  vegetation-soil-rock groundwater continuum

摘要:

本文系统总结了桂林毛村地下河观测站在岩溶关键带垂向上碳循环的监测工作，为基地进入岩溶关键带监测网络奠定基础。对岩溶植被层-土壤层-岩石层-地下水无缝连续体的碳循环监测，包括不同地质背景下典型植被的光合速率、自然植被下凋落物的分解（植被层）、不同土地利用方式下土壤碳库的组成及转化、土壤微生物及有机酸对碳酸盐岩的溶蚀（土壤层）、洞穴CO₂浓度及同位素的变化（气体-岩石作用层）、流域水体无机碳特征、外源水对岩溶碳汇过程的促进（地下水层）等方面。经过长期的科研积累，形成一套包括岩溶生物地球化学、岩溶水文过程、同位素示踪技术等在内的野外及室内研究方法，为流域尺度岩溶关键带碳循环的研究提供了技术支持和理论基础。但岩溶关键带碳循环过程中的生物作用及现代CO₂在岩溶关键带中的周转时间研究较少，亟待加强。桂林毛村地下河流域岩溶关键带碳循环的研究具有地域优势和学术优势，适合成为我国岩溶关键带监测站。

Abstract:

This paper systematically summarizes the monitoring of the carbon cycle of karst critical zone in Maocun subterranean river basin of Guilin,which lays a foundation for the base to enter the karst critical zone monitoring network. The carbon cycle monitoring of vegetation-soil-rock-groundwater continuum included the photosynthetic rate of typical vegetation under different geological backgrounds the decomposition of litter under natural vegetation conditions (vegetation layer),composition and transformation of soil carbon pool under the use of soil,carbonate rock dissolution by soil microbial and organic acid (soil layer),cave CO₂ concentration and isotope change (gas-rock layer),basin inorganic carbon flux and the promotion of karst carbon sink process by allogenic water (groundwater) and so on. After a long period of scientific research,a set of field and indoor methods were formed,including karst biogeochemistry,hydrological processes,isotope tracer technology,etc. These methods provided a technical support and theoretical basis for the study of carbon cycle in the critical zone of karst basin. However,the biological effects of the carbon cycle and the turnover time of modern CO₂ in the karst critical zone were less studied and needed to be strengthened. The research on the carbon cycle of karst critical zone in Maocun subterranean river basin of Guilin had geographical advantages and academic advantages. It was suitable to become the monitoring station of karst critical zone in China.