基于中国气象局国家气候中心新发布的中短期适应气候变化的新情景(RCP4.5)和极端情景(RCP8.5)下的气候预估数据,采用空间化后的CENTURY模型模拟探讨2011-2050年内蒙古草地植被净初级生产力(NPP)的时空变化特征.结果表明:区域尺度上,未来气候变化情景下内蒙古草地NPP年下降速率分别为0.57 g C·m~(-2)·a~(-1)(RCP4.5)、0.89 g C·m~(-2)· a~(-1)(RCP8.5);相对于基准时段,RCP4.5情景下内蒙古草地NPP在2020s、2030s、2040s分别下降11.6%、12.0%、18.0%,而RCP8.5情景下降幅分别为23.8%、21.2%、30.1%.不同气候情景下内蒙古草地NPP时空变化特征差异较大,但即使在RCP4.5下未来40年绝大部分草地NPP也将呈现下降趋势,15.6%的草地减产超过20%.这表明未来气候变化情景下内蒙古草地降水略增的态势不足以补偿因温度升高对草地植被初级生产力所产生的负面作用,草地资源的可持续发展将面临更大挑战.
英文摘要:
In this paper,the CENTURY-based modeling system (complying CENTURY model from a site-based model into spatial model) after being systematically calibrated was used to investigate future climate change under Representative Concentration Pathways Scenario (RCP,4.5 and 8.5) driven spatio-temporal changes in vegetation net primary productivity (NPP) of Inner Mongolia grassland during 2011 - 2050. The simulation showed that Inner Mongolia grassland NPP would greatly decrease with a rate of 0.57 g C·m~(-2)·a~(-1)(RCP4.5) and 0.89 g C·m~(-2)·a~(-1)(RCP8.5). NPP of Inner Mongolia grassland appeared to decrease by approximately 11.6% (2020s), 12.0%(2030s) and 18.0% (2040s) under the RCP4.5 in relation to baseline period,while its reduction could be exacerbated as 23.8% (2020s), 21.2% (2030s) and 30.1% (2040s) in the RCP8.5 at the regional scale. In addition,grassland NPP induced by future climate changes varied between different grassland types and times,strongly correlating with climate scenario. Even for the RCP4.5, however,a great majority (89.7%) of the grassland exhibited a decreasing trend in annual NPP, with 15.6% of the area decreasing by more than 20% compared with the baseline term. Therefore, although future precipitation rising could benefit vegetation growth,it might be still not enough to compensate for the negative effect of warming on the NPP of Inner Mongolia grassland,and the sustainable development of grassland resources might face a greater challenge.