To study the relationship between the spatial distribution characteristics of soil organic carbon (SOC) and land use in karst river basins, 22 057 soil samples from 2 755 soil profiles were collected with a grid-sampling method at a 150 m scale in the Houzhai River Basin. The SOC density characteristics under different land uses were analyzed. The results indicate that human disturbance, soil thickness and rock outcrop are critical factors to SOC density in the Houzhai River Basin. The land uses in the Houzhai River Basin with SOC density (0-100 cm) in descended order are paddy lands, arid lands, artificial fruit forestlands, garden lands, grasslands, abandoned lands, sloping croplands, arbor-shrub mixed forestlands, arbor forestlands, uncultivated lands, shrub lands and shrub-grass lands. The average SOC density in the top 1 m soil of Houzhai River Basin is 8.70 kg/m2 which is a little lower than the average SOC density in China (10.83 kg/m2), and the SOC storage in the Houzhai River Basin is 5.39×108 kg. In conclusion, scientific and reasonable rearrangement and management of land uses could enlarge the SOC storage capacity in a karst river basin.
In order to explore the planning and design model of ecological restoration in mining area under the concept of sustainable development and push forward the innovation of ecological restoration technology in mining area, this article introduced the permaculture design concept to the planning strategy and operation process of ecological restoration of coal mine wasteland. Taking the ecological restoration of the Wangshiwa coal mine, “the eldest son of the Republic”, as a case study, this paper analyzed the application status of zoning planning, sector analysis and cycle layout of the permaculture design in detail. The ecosystem service value of the Wangshiwa coal mine during 2014-2016 was estimated. It is found that the variability degree of the ecosystem service values of various ecosystems is rather balanced, among which the forest ecosystem had the greatest contribution to the total service value of ecosystem in mining area with the contribution rate being 69%, 77% and 79% in 2014, 2015 and 2016, respectively. The contribution of the grassland ecosystem was the second, whose contribution rate in each year was 15%, 13% and 12%, respectively. The contribution rate of farmland ecosystem in each year was 16%, 10% and 9%, respectively. The results show: 1) The permaculture design, which has ecological ethics substitution, is an effective planning model for ecological restoration of coal mine wasteland; 2) the permaculture design takes ecological risks into consideration, thus it can count the heavy metal pollution area in the zoning of ecological construction; 3 ) the permaculture design promotes the balance in the construction of ecological restoration system of coal mine wasteland and realizes the evolution of zonal natural ecosystem; 4) the permaculture design completes soil nutrient accumulation through biological elements and incorporates the ecological rehabilitation system of coal mine into biogeochemical cycle; and 5) the permaculture design can achieve the sustainable development of ecological, economic and social integrated systems of coal mine wasteland. The results of the research can provide a reference for the theoretical research and practice activities of mining ecological restoration planning and design.
The proposal or implementation of major resource development and utilization project often receives widespread concerns from the whole society. How to correctly understand and scientifically evaluate various hot research topics about resources and environment is the key point of discussion. This paper argues that the development project of any major resources must follow natural laws, ecological laws, resource laws, and economic laws. We must carry out systematic and comprehensive pre-stage surveys based on the country’s strategic needs and geopolitical relations, evaluate the ecological safety and the resource engineering safety from the perspectives of multiple disciplinarians, and make correct judgments on the scientific value, social value and economic value of the project. Authors strongly suggest that: 1) the future construction of resource and environmental engineering projects should not make forward in great leaps; 2) for protecting the beautiful home of the earth, we need to recognize laws of natural resource systems through scientific study; 3) resource scientists should fulfill their social responsibilities; 4) academic contending should be advocated on the basis of scientific research and scientific attitudes; 5) scientific issues are better to be discussed by scientists; and 6) it should be very cautious to support researches on controversial scientific topics by public welfare funds.