内蒙古草地生产力时空变化及驱动因素分析

基于草地资源普查资料和GIS技术,以生物量与可食牧草比例作为影响草地生产力的主要因子,以县域为单位,对内蒙古草地生产力的时空变化特征及其分布的地域差异性进行了分析.结果表明:2000-2003年与1981-1985年相比,大部分地区生物单产及可食牧草产量均明显减少,可食牧草比例也明显降低;生物单产、可食牧草产量以及可食牧草比例高值区与次高值区均明显减少;大部分地区草量变化与草质变化具有时空一致性.最后从气候变化、草畜矛盾、现有草原管理制度及建设状况方面,对内蒙古草地生产力变化成因进行了分析.

Analysis on the Spatiotemporal Change of Steppe Productivity and Its Driving Factors in Inner Mongolia

Inner Mongolia is rich in steppe resources. Affected by natural factors, such as the landforms, climate and soils, the zonality of steppes in Inner Mongolia is significant, and 5 kinds of zonal steppes including the meadow steppe, typical steppe, desert steppe, steppified desert and desert are distributed from the northeast to the southwest. Because of the impacts of vulnerable natural environment and irrational human activities, the steppe degeneration and desertification in Inner Mongolia has become more and more serious since recent years,the productivity of steppes and the proportion of edible grasses have been reduced, and the sustainable social and economic development has been restricted. Based on the general investigation data of steppes and GIS, in this paper the spatiotemporal change of productivity and the regional distribution of steppes in Inner Mongolia Autonomous Region are analyzed by regarding the proportions of biomass and edible forage grasses as the main factors affecting the productivity of steppes. The results show that the biomass, yield of edible forage grasses and proportion of edible forage grasses during the period of 2000 - 2003 were obviously decreased compared with that during the period of 1981 - 1985; the areas with high biomass, yield of edible forage grasses and proportion of edible forage grasses were significantly reduced during this period, and the spatiotemporal change of the biomass accorded with that of the proportion of edible forage grasses. The causes resulting in the change of productivity of steppes are analyzed from the aspects of climate change, livestock imbalance of the steppes, management measures and restoration of the steppes.