摘要
利用内蒙古自治区48个气象观测站点50a(1962-2011)的月平均气温和降水量观测数据,基于Holdridge模型计算内蒙古气候区划指标划分不同类型草原区,模拟内蒙古草地类型50a的变化趋势。结合实际草地类型分布图,分析不同草原区1962-2011年的气候变化特征,并探讨气候变化对草地类型分布的影响。结果表明:内蒙古典型草原区的东部区域、荒漠草原区和草原荒漠区均属高温地带,而森林草原区和典型草原区的大部分区域属低温地带。50a间内蒙古草原区气温具有显著上升趋势(P<0.05),各类型草地区的年平均气温均在1990年左右发生突变,同年呈显著升高趋势,而生长季气温在1995年左右发生突变,并于2a后呈显著升高趋势。内蒙古草原区降水分布格局具有明显的地带性,由西至东降水量递增且梯度差异明显。年降水量变化趋势表现为,森林草原区自1997年开始显著增加,至2002年回落;典型草原区自1992年开始年降水量显著增加,至2006年回落(P<0.05);荒漠草原和草原荒漠区年降水量变化趋势不显著。生长季降水量的变化则表现为,森林草原和典型草原区在研究期内呈小幅减少—小幅增加—小幅减少趋势,其它类型草地降水变化与年降水量趋势一致。总体上,内蒙古草原区的降水变化,森林草原和典型草原区具有较大波动性,荒漠草原区于近年产生少许变动,而草原荒漠区相对较稳定。1962-2011年气温和降水量变化导致森林草原区面积在前30a呈增加趋势,后20a呈减少趋势;荒漠草原和草原荒漠区的边界逐渐向东扩展,典型草原区也将扩展至部分森林草原区域。总之,研究期内内蒙古草原区降水量在后期减少、气温持续升高,由于蒸散量加大可能导致土壤干旱,从而影响内蒙古草地生态系统分布格局的变化。
Based on the meteorological data in the Inner Mongolia autonomous region and Holdridge life zone classification climate system,we analyzed the change characteristics of temperature and precipitation from 1962 to 2011,compared the grassland types distribution during the 1962s(1962-1971) and the beginning of the 21stcentury(2002-2011),explored the impact of climate change on potential distribution of grassland types in Inner Mongolia.The results showed that during 1962-2011,the annual and growing seasonal mean temperatures were risen significantly in the research area(P < 0.05),and the time of abrupt temperature change happened in 1990,in growing season the time delayed for 5 years than the annual mean temperature change.The precipitation change in forest steppe and typical steppe area showed a decreasing trend(2002-2006) after an increasing at first(1992-2002)(P <0.05),while there was no significant change in desert steppe and desert area; The fluctuation of precipitation in the eastern area was greater than the western Inner Mongolia.The transition area of the typical steppe to desert steppe gradually expanded in past 50 years,while the forest steppe also had a change trend to typical steppe,contrast the temporal and spatial variation of temperature and precipitation with the distribution change of grassland types by climate distribution indicators,the impacts of precipitation change on grassland distribution was more significant than temperature in Inner Mongolia.The reducing of growing seasonal precipitation and resulting soil severe drought in a non-growing season,and also increasing temperature made the higher evapotranspiration,would be impact the distribution of grassland ecosystem in Inner Mongolia.
出处
《中国农业气象》
CSCD
北大核心
2015年第2期139-148,共10页
Chinese Journal of Agrometeorology
基金
国家科技支撑计划项目(2013BAC09B03
2011BAC07B00)
农业部"国家牧草现代产业技术体系"项目(CARS-35)