内蒙古草地生产力资源和载畜量的区域尺度模式评估

在气候变化和人类活动的干扰下熏内蒙古草地在过去50年里产生大面积的退化沙化。论文在大气植被相互作用模式穴AVIM雪的基础上发展了一个区域评估模型AVIMia。该模式包括陆面物理过程、植被生长过程和草地利用模式,用来评估放牧利用和气候变化对草地生产力和载畜量的影响。结果表明:内蒙古草地区域生产力剧烈的年际变化与降水量密切相关,而与温度没有明显相关关系。模式估计内蒙古草地总的地上生产力为771.7×108kg/a,可食地上生物量为498.1×108kg/a,典型草原和草甸草原占了大部分的生产力。据此推算的内蒙古地区总的载畜量为45.51×106羊单位,与1997年实际载畜量比较,超载100%。因而熏提出过牧可能是内蒙古草地大面积退化沙化的主要原因,甚至超过气候变化的影响。

Assessment of the productivity and livestock carrying capacity of Inner Mongolia grassland by regional scale modeling

In this paper a regional assessment model AVIMia is designed.AVIMia consists of two components:original AVIM(Atmosphere-Vegetation Interaction Model)and an impact assessm-ent model.Over the past 50 years the arid/semi-arid grassland of northern China degraded severely due to the changes in climate and social economy.AVIMia is applied to assess the impacts of climatic changes and human activities on grassland in northern China,based on historical data and the different climatic and social scenarios for this region.For the assessment of grassland,the following factors are particularly taken into consideration:grazing,cultivation on grassland communities.The model is validated by observed data of Inner Mongolia semi-arid grassland.Both the data analysis and model assessment show that the total aboveground NPP of Inner Mongolia grassland is 771.7×108kg/yr.Edible aboveground biomass is 498.1×108kg/yr.Typical steppe and meadow steppe dominate the production of this region.The total estimated livestock holding capacity is 45.51million sheep unit.The grassland is overgrazed more than 100% in Inner Mongolia.Overgrazing is one of the most important reasons inducing the widespread degradation and desertification.