大兴安岭区域未来气候变化趋势及其对湿地的影响

基于未来2种排放情景下的RCM-PRECIS输出的大兴安岭区域气温与降水量预测数据,采用M ann-Kendall(简称M-K)非参数检验法和线性倾向率法,分析大兴安岭区域2015-2050年气候变化趋势及其对湿地的影响.结果表明,在未来2种情景下,2015-2050年的年平均气温升高显著,A2情景的增温速率(0.54℃·(10a)~(-1))高于B2情景(0.41℃·(10a)~(-1)),与东北地区增温速率(0.56℃·(10a)~(-1))一致,B2情景增温速率低于东北地区增温速率;大兴安岭区域自2032年气温开始出现增暖突变现象,增温幅度显著增大.2种情景下季节平均气温的增温速率大小依次为夏季、冬季、春季和秋季,A2情景夏、冬、春、秋季分别为0.59、0.56、0.56、0.52℃·(10a)~(-1),B2情景分别为0.48、0.47、0.42、0.37℃·(10a)~(-1);各季突变增温时间点和增温趋势显著时段存在差异.2种情景下2015-2050年的年降水量有微弱的减少趋势,M-K检测基本无显著变化;季节降水总体而言,大兴安岭区域未来36 a降水量仍以夏季为主,占全年降水量的60%左右;春季和秋季次之,各占全年降水量的18%~19%.未来大兴安岭区域气候呈现暖干化趋势,其中21世纪20、40年代大兴安岭湿地受到气候暖干化的胁迫相应较强,未来气候暖干化趋势是大兴安岭湿地生态系统萎缩和退化的主要诱因之一,未来大兴安岭湿地生态系统仍将受到气候暖干化趋势的巨大威胁,面临萎缩和严重退化趋势.

Climate change trend in future and its influence on wetlands in the Greater Khingan Mountains

The study of climate change in future and its influence on wetlands in the Greater Khingan Mountains has significance for the region to deal with and adapt climate change.Based on the air temperature and precipita-tion predicted by RCM-PRECIS under the IPCC Scenarios A2 and B2,with the methods of Mann-Kendall (M-K method)nonparametric test and linear tendency rate,climate change trend and its influence on wetlands were analyzed from 2015 to 2050 in the Greater Khingan Mountains.The results show that under the Scenarios A2 and B2,yearly average air temperature will increase significantly,the warming rate of Scenario A2 will be higher than that of Scenario B2,the warming rate for Scenarios A2 and B2 will be 0.54 ℃·(10a)-1 and 0.41 ℃· (10a)-1 ,respectively,and the warming rate of Scenario A2 will be consistent with that of Northeast China (0.56 ℃·(10a)-1 ),the warming rate of Scenario B2 will be lower than that of Northeast China from 2015 to 2050. Since 2032, air temperature will appear an abruptly warming, especially in the Greater Khingan Mountains.For seasonal average air temperatures under the two scenarios,the warming rate in descending order will be summer,winter,spring and autumn,respectively;the warming rate in descending order for Scenario A2 will be 0.59,0.56,0.56,and 0.52 ℃·(10a)-1 ,respectively;that for Scenario B2 will be 0.48,0.47, 0.42 and 0.37 ℃·(10a)-1 ,respectively.Temporally,the warming mutation points will be different;the sig-nificant warming periods will be different too in different seasons.Under the two scenarios,yearly precipitation will be slightly decreasing from 2015 to 2050,but there will be no significant change through the M-K testing. Overall,the precipitation in summer will be nearly all the same,accounting for about 60%of the annual precipi-tation,followed by spring and autumn,accounting for about 18%-19% of the annual precipitation,for the future 36 a in the Greater Khingan Mountains.The future climate will be warming and drying in the Greater Khingan Mountains.The wetland ecosystem in the Greater Khingan Mountains will be heavier stress by the future climate warming and drying in the 2020 s and 2040 s.The warming and drying climate trend will be one of the main cause for atrophy and degeneration of the wetland ecosystem in the Greater Khingan Mountains.The wetland ecosystem will still be under great threat from climate warming and drying,and atrophy and severe deg-radation will be occurred in the Greater Khingan Mountains.