| The problem of soil erosion has become one of the serious ecological crises facing the world.The traditional soil and water conservation measures are mainly based on governance,and the comprehensive benefits of economy,society,ecology,and landscape still need to be improved.Close-to-natural soil and water conservation is based on the concept of ecological restoration,and measures are imitated according to the development law of nature to give full play to the economic benefits,social benefits,ecological benefits and landscape benefits of the measures to promote stable and sustainable development of the measures.In this study,the close-to-natural soil and water conservation of slope farmland is taken as the research object.And we analyzed the origin and development of the close-to-natural concept,put forward the concept and principle of close-to-natural soil and water conservation.Based on the application of analytic hierarchy process,a close-to-natural soil and water conservation evaluation system of slope farmland was constructed,and the close-to-natural evaluation of typical slope farmland management measures in Qinling-Bashan Mountain areas was carried out.The conclusions are as follows:Based on the theories of ecology and sustainable development,the concept and characteristics of close-to-natural soil and water conservation measures for slope farmland are proposed,and they are distinguished from the theories of traditional slope management,vegetation restoration,engineering measures,flexible water management and nature-based solutions to identified the characteristics of close-to-natural soil and water conservation.The ultimate goal of close-to-natural soil and water conservation is to promote soil and water conservation measures to give full play to economic benefits,social benefits,ecological benefits,and landscape benefits to achieve harmony between man and nature.The ideological origin,theoretical basis,connotation and principle of close-to-natural soil and water conservation are studied.The "close-to-natural" soil and water conservation management concept is based on "Respect nature,earn nature",which is the improvement of traditional soil and water conservation in ecology and landscape.It is based on soil and water conservation,hydrology,geomorphology,landscape ecology,ecological aesthetics,economics and sociology.It expands the traditional soil and water conservation to provide theoretical support for close-to-natural soil and water conservation in terms of measures construction,vegetation spatial pattern and aesthetics.At the same time,the principle of minimum erosion,respect for nature,conformity to nature and the principle of native species are proposed to provide guidance for the implementation of soil and water conservation measures on slope farmland.An evaluation index system of near-natural soil and water conservation on slope farmland was constructed and applied in the field in southern Shaanxi.and then comprehensively consider the three aspects of soil and water conservation function,close-to-natural degree and economic benefit,and screen out representative evaluation indexes such as soil erosion,soil organic matter,saturated water content,number of species,plant community regional characteristics,vegetation coverage / vegetation canopy closure,vegetation growth,and coordination between plant communities and the overall environment,etc.to establish a close-to-nature evaluation system with 3 levels and 16 indicators.The evaluation system is applied to the typical slope farmland management measures in the Qinling-Bashan Mountain areas.The 33 sample plots surveyed had a comprehensive score between 0.54-0.87,which was concentrated and showed good and moderate levels.The low score of terraces in the comprehensive score indicates that there are still many problems to be solved in the current terrace construction.The application and evaluation results of the close-to-natural soil and water conservation evaluation index system on slope farmland are ideal.The research results can provide reference and ideas for the theories,evaluations and measures of close-to-natural soil and water conservation. |
