西南喀斯特石漠化生态系统土壤有机碳分布特征及其影响因素

喀斯特石漠化已成为制约我国西南地区社会经济可持续发展最严重的生态地质环境问题,其恢复重建已成为我国社会经济建设中一项重要内容。土壤有机碳作为土壤质量评价的重要指标,可以综合反映土地生产力、环境健康功能,另一方面土壤有机碳也间接影响了陆地生物碳库,是陆地生态系统碳平衡的主要因子,它的转化和积累变化直接影响全球碳循环动态,已成为生态科学领域研究的热点之一。系统的总结了西南喀斯特石漠化地区不同土地覆被/土地利用、不同等级石漠化环境土壤有机碳的空间和季节分布特征。结合前人研究成果,进一步分析了影响喀斯特石漠化地区土壤有机碳分布的自然(气候、地形与土壤性质、植被等)和人为(土地覆被/土地利用变化、农业管理措施等)各因素,并提出增加喀斯特石漠化地区土壤有机碳含量的对策。研究结果为喀斯特石漠化退化生态系统恢复重建、石漠化地区土壤综合利用、增加碳截存应对全球碳循环减源增汇等提供了重要的科学参考。

Distribution characteristics of soil organic carbon and its influence factors in the karst rocky desertification ecosystem of Southwest China

Karst rocky desertification has become a very significant issue in ecological and geological environments, and it seriously restricts the sustainable development of society and economy in Southwest China. Rehabilitation and restoration of karst rocky desertification have become very important for the society and economy of China. Soil organic carbon is an important parameter used for evaluating soil quality. It can indicate the status of land productivity and environmental health. Soil organic carbon is the main factor for the carbon balance of a terrestrial ecosystem and can indirectly affect the terrestrial biological carbon pool. Changes in the transformation and accumulation of soil organic carbon can directly affect the dynamics of the global carbon cycle. Thus, soil organic carbon has become a research hotspot in the field of ecology. In the present study, first, we systematically summarized the spatial and seasonal distribution characteristics of soil organic carbon among different land cover/land use and different rocky desertification degrees of the karst rocky desertification ecosystem in Southwest China. Second, on the basis of previous studies and field surveys, we deduced the influence factors, including natural and human factors such as climate, landform, soil properties, vegetation cover, land cover/land use change, and agricultural management practices, related to the distribution of soil organic carbon. Finally, we proposed measures to improve the soil organic carbon content of the karst rocky desertification ecosystem. Our results can offer an important scientific basis for the rehabilitation and restoration of karst rocky desertification and rational soil utilization in the karst rocky desertification ecosystem and improve soil carbon sequestration to increase the carbon sink in the global carbon cycle.