喀斯特地区石漠化生态修复对土壤生物多样性的影响

我国西南喀斯特地区是具有土层薄和土被不连续等特征的生态脆弱区,人为过度干扰和土地不当利用导致了生境退化甚至石漠化的发生。从“九五”规划到“十三五”规划,为了有效抑制并逆转石漠化趋势,生态修复措施得到普遍的推广应用。“十四五”规划进一步提出科学推进石漠化综合治理,提高生态系统自我修复能力和稳定性。从土壤微生物、原生动物、线虫、微节肢动物、蚯蚓和线蚓等方面,综述了喀斯特地区生态修复对土壤生物多样性的影响。研究发现：(1)喀斯特生境细菌和真菌的多样性高于非喀斯特生境,原因是喀斯特具有较高的土壤pH和钙含量;(2)与非喀斯特生境相比,喀斯特生境土壤动物类群数相差不大而个体密度较低;(3)石漠化过程伴随着植被退化,降低了土壤微生物种类和功能多样性,土壤动物的个体密度和类群数也呈现降低趋势;(4)生态修复促进植被正向演替,土壤微生物量和酶类活性逐渐上升,真菌/细菌生物量比值增大,土壤动物个体密度和类群数增加,有利于土壤固碳和生态修复。因此,土壤生物多样性是适合指示喀斯特石漠化的生态修复的生物学指标。研究建议：(1)在传统分类鉴定基础上,结合宏基因组学、宏蛋白质组学和同位素标记等技术,完善生态修复的...

Impact of ecological restoration of rocky desertification on soil biodiversity in karst area: A review

Karst region in southwestern China is an ecologically fragile area with slow pedogenesis, shallow soil layer, discontinuous soil cover structure and low water holding capacity. Excessive human disturbances and improper land uses led to land degradation, even serious rocky desertification. From the 9th to the 13th Five-Year Plan, the ecological restoration measures have been applied widely to suppress and reverse rocky desertification, and the related researches have been increased drastically in recent years. The "14th Five-Year Plan" in China will advance scientifically the comprehensive management of rocky desertification, so as to improve the self-repair capacity and the stability of vulnerable karst ecosystem. This paper reviewed the impacts of ecological restoration measures on the diversity of soil microorganism, protozoa, nematode, micro-arthropod and earthworm in karst areas. The results showed that:(1) the diversities of bacterial and fungi were higher in the karst habitat than those in the non-karst habitats, which may be caused by higher pH and calcium content of the karst habits. (2) There were no significant differences in fauna group number between karst and non-karst habits, but the densities of soil fauna were significant lower in the karst habit than those in the non-karst habits. (3) The rocky desertification, as the extreme degradation process in karst area, reduced the microbial species and function diversity. Also the faunal density and group number showed a decline trend. (4) The ecological restoration measures changed the vegetation structure, increased the vegetation coverage and soil fertility, and then gradually increased soil microbial biomass, enzyme activities, and fungal/bacterial ratio, consequently favored soil carbon sequestration and ecosystem restoration. Furthermore, the ecological restoration measures increased the faunal density and group number. In conclusion, the soil biodiversity can be used to indicate the degradation process or ecological restoration process in karst area. In the future, we suggested that:(1) besides the traditional classification and identification of soil biota, some novel technologies such as metagenomics, metaproteomics, and isotope probing techniques should be involved in the researches of the degradation or ecological restoration process in karst area. (2) Strengthening the function study of soil biodiversity in the ecological restoration. And (3) by building long-term field ecological observatory stations, to study the real response of soil biodiversity to the ecological restoration process. These further studies would make important contribution to the clarification of the maintenance mechanism and ecosystem functions of soil biodiversity, and promoting ecological restoration of the degraded karst land.