气候变化对内蒙古中部草原气候生产潜力的影响

Influence of Climate Change on Potential Climate Productivity in Grassland of Central Inner Mongolia

根据内蒙古中部草原各样点47a的气候数据,基于Miami和Thornthwaite Memorial气候模型,分析研究区域不同草原类型草地生产潜力和影响气候生产潜力的气候驱动力。结果显示,内蒙古中部草原的气候生产潜力由东向西表现出与地理分布和降水量分布趋势一致的差异性,农牧交错带草地>典型草原>荒漠草原>草原化荒漠,其气候生产潜力在3000～7000kg.hm-2.a-1。研究区域的气候资源利用率在23.8%～62.3%,不同草原存在一定的差异性。分别采用草原样方取样实际产量数据、气候数据和气候生产力模型数据计算分析表明:与温度相比,降水量是影响研究区域牧草产量和气候生产潜力的主要气候驱动力,温度与降水对草原气候生产潜力都具有正效应,不同草原类型温度与降水变化对气候生产潜力的影响有差异性。温度每升高或降低1℃,草地气候生产潜力升高或降低6.75～29.07kg.hm-2.a-1,降水量每升高或降低1mm,草地气候生产潜力升高或降低0.83～1.86kg.hm-2.a-1。未来气候"干暖化"的趋势下,研究区域温度升高增加的气候生产潜力作用小于由蒸散量增加引起的减产作用,因而导致草地气候生产潜力下降,受水分限制作用越明显的草原,其气候生产潜力下降的趋势越显著。

Based on the climate date in 1961 - 2007 in the grassland of the Central Inner Mongolia, the response of the potential climate productivity to the climate change was analyzed, by using the Miami model and Thornthwaite Memorial model. The climatic factors affected the productivity were discussed. The results showed that the potential climate productivity in the grassland of the Central Inner Mongolia had the consistent difference with the geographical dis- tribution and the precipitation distribution. The potential climate productivity was with 3000 -7000kg·ha^-1each year, which distributed in the different grassland types from high to low in following order： steppe, agro-pastoral ecotone, desert steppe, steppe desert. The climatic utilization was by 23.8% -48.2% , which varied in the different grasslands. The precipitation was the key climatic factor limited the potential climate productivity and actual productivity by analyzing experimented date and climate productivity modelling. Both temperature and precipitation increase could enhance the potential climate productivity. The impact of temperature and precipitation change on the potential climate productivity varied in the different grassland. The potential climate productivity increased or decreased by 6.75 - 29.07kg·ha^-1 each year as the temperature increased or decreased by 1℃, while the potential climate productivity increased or decreased by 0.83 -1.86kg·ha^-1each year as the precipitation increased or decreased by 1mm. Under the background of drier and warmer tendency, the increasing amount of potential climate productivity with temperature increase was less than decreasing amount with evapotranspiration increase. Therefore, climate drying and warming in the future will lead to potential climate productivity decrease. The more obviously the potential climate productivity was limited by precipitation, the more significantly the potential climate productivity decreased.