Recent changes in land use and productivity in agro-pastoral Inner Mongolia, China
Sammanfattning: This study challenges the prevailing assumption that the expansion of cultivated land areas and increasing number of livestock in the agro-pastoral regions of northern China have aggravated the process of land degradation since the start of the rural reforms in 1978. Land-use and productivity trends in the Inner Mongolia Autonomous Region (IMAR), with special attention to the Keerqin steppe region, have been analysed. A combination of methods including household surveys, analysis of agro-statistics and satellite-based productivity modelling has been applied on different spatial scales. Increase in grain yields was found, though considerable interannual variability persists, rendering livelihood insecure for farmers. Although statistics for cultivated land area are inferior the area of cultivated land seems to be increasing mainly in the pastoral counties. Farmers acknowledge the importance of the 30-year contract on cultivated land introduced in 1997 with respect to their investment in long-term management, but ranked the availability of chemical fertilizers and the economic means to buy them as more critical for crop production than soil erosion. This indicates the increase in use of and dependence on agro-chemicals, a trend confirmed by regional statistics, and concern is raised regarding the sustainability of the rapid agricultural development. The spatio-temporal dynamics of primary production for the IMAR was analysed by means of a regionally adapted light use efficiency model. The model, driven by a combination of NOAA AVHRR data and climatic data, has been used to map monthly Gross Primary Production (GPP) for the period 1982-1999. Though the high inter-annual variability in primary production undermines the identification of significant trends, it is indicated that in the western regions there has been no change in biological production, whereas a large area in central IMAR shows a marked increases for the period 1982-99. A combination of increasing crop yields, an increase in precipitation, as well as afforestation projects are probable factors explaining the pattern of regional increase in primary production.
Denna avhandling är EVENTUELLT nedladdningsbar som PDF. Kolla denna länk för att se om den går att ladda ner.