Wei Chaofu

Land use change and its corresponding ecological responses: A review

This paper reviews the research on land use change and its corresponding ecological responses. Patterns of land use changes in spatio-temporal level are produced by the interaction of biophysical and socio-economic processes. Nowadays, the studies derived from different socioeconomic conditions and scales show that at short-term scale, human activities, rather than natural forces, have become a major force in shaping the environment, while biophysical factors control the trends and processes of land use change under the macro environmental background. Providing a scientific understanding of the process of land use change, the impacts of different land use decisions, and the ways that decisions are affected by a changing environment and increasing ecological variability are the priority areas for research: (1) explanation of scale dependency of drivers of land use change; (2) quantification of driving factors of land use change; (3) incorporation of biophysical feedbacks in land use change models; and (4) underlying processes and mechanisms of ecological impacts of land use change.

Impact of land cover types on the soil characteristics in karst area of Chongqing

The 26 plots including natural forestland, secondary forestland, shrub-grassland, sloping cropland, artificial forest and abandoned field, were selected to discuss the impact of land cover on the soil characteristics in the three karst districts of Chongqing. The results showed that: (1) After the vegetation turned into secondary vegetation or artificial vegetation, or reclamation, soil physical properties would be degraded. In the surface-layer soil of sloping cropland, the contents of > 2 mm water-stable aggregates decreased obviously with apparent sandification. (2) The contents of soil organic matter and total nitrogen are controlled completely by vegetation type and land use intensity. The increasing trend is rather slow in the early days when over-reclamation is stopped and the land is converted to forest and pasture. (3) Herbaceous species increase and woody plants species decrease with the increase of land use intensity, therefore, the soil seed banks degrade more seriously. (4) The soil degradation index has been set up to describe the relative soil degradation degree under the conditions of different vegetation types. (5) Land cover has a significant effect on karst soil characteristics, land degradation in the karst ecosystem is essentially characterized by the different degradation of soil functions that serve as water banks, nutrient banks and soil seed banks.

Mountain Land Use Planning of Metropolitan Suburbs:the Case of the Jinyun Mountain and Its Surrounding area,Chongqing,China

Open space of metropolitan suburbs in mountain region, has been increasingly becoming the coupling mosaic structure of industrial actions and landscape behaviors. However, the local governments, when making land use planning, often aim at economic development, and rarely refer to the coordination of compatibilities and conflicts between industrial actions and landscape behaviors in the mosaic structure. In this study land use in the Jinyun Mountain and its surrounding area, Chongqing is adjusted by gray multi-objective programming approach and local-level decision-making process to cope with conflicts between objectives for human welfare and objectives for landscape conservation. The results indicate that: 1) the compatibilities and conflicts among different behavior characters and different landscape types result in the compatibilities of landscape to human behavior; 2) a land use planning in the study area is produced based on the sustainable land use and social-eco development, which pays more attention to the resources and environment constraints and economic objectives, and follows the distribution law of rare resources; 3) in the study area, cultivated land of 1,207.27 ha can meet the demands for food and byproducts by the residents there, orchard land and forestland of 632.55 ha, 2,276.61 ha, respectively can provide enough space for the local people to improve their living structure and meet their demands for recreational activities, and urban residential land, rural residential land, mining land and transportation land of 1,107.60 ha, 120.27 ha, 162.48 ha, 100.91 ha, respectively can satisfy the resident’s economic development and infrastructures; 4) the equilibrium among industrial actions, landscape accessibility and ecological conservation can be obtained by analyzing the possible impacts of human activities on landscape ecological process in open space of metropolitan suburbs in mountain areas.Open space of metropolitan suburbs in mountain region, has been increasingly becoming the coupling mosaic structure of industrial actions and landscape behaviors. However, the local governments, when making land use planning, often aim at economic development, and rarely refer to the coordination of compatibilities and conflicts between industrial actions and landscape behaviors in the mosaic structure. In this study land use in the Jinyun Mountain and its surrounding area, Chongqing is adjusted by gray multi-objective programming approach and local-level decision-making process to cope with conflicts between objectives for human welfare and objectives for landscape conservation. The results indicate that: 1) the compatibilities and conflicts among different behavior characters and different landscape types result in the compatibilities of landscape to human behavior; 2) a land use planning in the study area is produced based on the sustainable land use and social-eco development, which pays more attention to the resources and environment constraints and economic objectives, and follows the distribution law of rare resources; 3) in the study area, cultivated land of 1,207.27 ha can meet the demands for food and byproducts by the residents there, orchard land and forestland of 632.55 ha, 2,276.61 ha, respectively can provide enough space for the local people to improve their living structure and meet their demands for recreational activities, and urban residential land, rural residential land, mining land and transportation land of 1,107.60 ha, 120.27 ha, 162.48 ha, 100.91 ha, respectively can satisfy the resident’s economic development and infrastructures; 4) the equilibrium among industrial actions, landscape accessibility and ecological conservation can be obtained by analyzing the possible impacts of human activities on landscape ecological process in open space of metropolitan suburbs in mountain areas.

The effects of land uses on purplish soil erosion in hilly area of Sichuan Province, China

In order to evaluate the soil erosion rate for different land uses and make recommendations on land-use alternatives for erosion control in hilly and mountain areas on a Purplish soil (Regosols in FAO taxonomy), experimental data were obtained from three continuously monitored sites located at Yanting, Nanbu and Pengxi of Sichuan province. The data showed that the rank of erosion rate is farmland > unfenced grassland > fenced grassland > forestland. The erosion rate of farmland was more than 3 times higher than that of forestland and fenced grassland, indicating that restricting human activity is crucial for over-erosion. The erodibility was higher at the initial period of rainy season for all the three types of land use. The erosion rates of fenced grassland and mature afforestation land were not proportional to rainfall intensity because these land uses changed impact energy of the rainfall. This research showed that restricting human activity, intensifying the management of initial period of rainy season, and increasing the cover rate of land surface are the three major measures for soil erosion prevention. It is recommended that farmers should cease cultivation on farmland at the top of hills and steep slope land return those lands back to grassland or forestland.