Ecological restoration effect and carbon neutrality contribution of biological soil

Western China is one of typical ecologically fragile and sensitive areas with the most serious soil erosion problem. The problems of surface damage and ecological carbon sink decline caused by the superimposition of coal resource exploitation and drought fragile natural environment is becoming more severe in the western mining areas. Thus,it is necessary to explore a kind of ecological restoration and carbon sequestration technology with high habitat compatibility and rapid greening in accordance with terrain change. Biological soil crusts widely distributed in western China,are complex organic integrities formed by soil microorganisms,cryptogamic plants,e.g. cyanobacteria,eukaryotic algae,lichens and mosses,as well as gluing soil surface particles together. As primary builders of topsoil biological cover in arid and semiarid,biological soil crusts are important carbon sinks in terrestrial ecosystems,which could change the microtopography of topsoil,increase rainfall infiltration and delay or reduce runoff,as well as influence the survival and reproduction of soil microorganism and animals. Meanwhile,it plays an important role in soil ecohydrological,soil biological and geochemical cycle processes. As for the primary problems of ecological environment in the western mining areas,the influence of biological soil crusts on soil nutrient accumulation,nitrogen fixation,wind and water erosion in ecological function were reviewed in this study. In addition,the diversified ecological restoration models,including dust control by cyanobacterial biocrust,mining subsidence crack restoration,threedimensional configuration restoration of biological soil crust and herbs,shrubs and arbors,were expounded. Based on the experimental results,the organic carbon content in moss biocrust was significantly higher than that in cyanobacterial biocrust by 90.3%,and the organic carbon content was increased by 107% at the mycorrhizal fungi and artificial moss biocrust combined with 3∶1-5∶1 ratio. Moreover,the contributions of carbon sequestration of biological soil crusts to carbon neutralization in the coal mining areas,including mycorrhizal fungi and artificial moss biocrust combined with 3∶1-5∶1 ratio of carbon sequestration,biological soil crust combined with and arbors,shrubs,and herbs for carbon sequestration,longterm remediation of biological soil crusts for soil carbon sequestration,were proposed. These works provide some diversified theoretical references and technical support for land reclamation and ecological restoration in the western mining areas under the background of carbon neutrality,so as to accelerate the sustainable development of ecological environment restoration in the western mining areas.