结构—功能—生境框架下的西南喀斯特生态系统脆弱性研究进展

特殊的地质背景与生态环境叠加强烈的人类活动,导致中国西南喀斯特地区生态系统呈现显著的脆弱性特征。从生态系统敏感性和适应性角度出发,喀斯特生态系统结构、功能和生境对外界扰动响应的脆弱性特征研究已取得一定进展,尤其是借助物种多样性、生态系统生产力、土壤水分/养分等指标揭示了喀斯特生态系统对土地利用/覆被变化、石漠化等过程的敏感性等方面,但综合野外试验、数值模拟、数理统计等手段的生态系统敏感性定量化研究仍较薄弱。在生态系统适应性方面,虽然具有喜钙、耐旱以及石生等特性的植物种群通过形态结构和生理功能的自我调节能够呈现出对岩溶环境的适应性,但喀斯特生态系统对人类干扰和气候变化等环境胁迫响应的适应机制仍缺乏长期的生物及理化过程研究。今后,应针对生态系统结构、功能、生境间的正反馈机制,增强系统组分的耦合分析,加强喀斯特生态系统脆弱性驱动机制研究与定量评估,突出系统脆弱性在石漠化遏制和生态恢复重建中的关键地位。

Review of ecosystem vulnerability studies in the karst region of Southwest China based on a structure-function-habitat framework

During the past decades, due to the intensified human disturbance and its special geological background and ecological environment, karst ecosystem in the southwestern part of China exhibited significant vulnerability, which hinders the sustainable development of the social-economic-ecological system of the region. Based on system sensitivity and adaptability, a large number of studies have investigated the vulnerability of karst ecosystem structure, function, and habitat to external disturbance. Especially, indicators of ecosystem diversity, key species, productivity, and soil physical/chemical properties were applied to reveal ecosystem sensitivity to land use/cover change and rocky desertification. However, research on quantification of ecosystem sensitivity by field experiment, mechanism models, and mathematical statistics, is less advanced. Although some karst-suitable plants present adaptability to karst drought environment by self-regulation of morphological structure and physiological function, the ecosystem adaption mechanism or biophysical/biochemical processes in response to environmental threat (e.g. human disturbance and climate change) remain unclear. Due to the close interaction of ecosystem structure, function, and habitat, future research should examine the response of coupled ecosystem components to promote the study of driving mechanism and quantitative assessment of karst ecosystem vulnerability. Furthermore, research on ecosystem vulnerability at different succession stages of karst rocky desertification needs to be strengthened to advance rocky desertification control and ecological restoration and reconstruction.