近40年甘南草原生命地带偏移趋势及干湿变化  

The Moving Tendency of Holdridge Life Zone with Its Dry and Wet Climate Changes of Gannan Meadow in Recent 40 Years

作　　者：王建兵[1,2] 

机构地区：[1]中国气象局兰州干旱气象研究所,甘肃省干旱气候变化与减灾重点实验室,兰州730020 [2]甘肃省甘南藏族自治州气象局,合作747000

出　　处：《应用气象学报》2012年第5期604-608,共5页Journal of Applied Meteorological Science

摘　　要：利用Holdridge生命地带系统对1971—2010年甘南草原的Holdridge生命地带偏移趋势及干湿变化进行分析,发现甘南草原目前仍属于青藏高原高寒植被地区的亚高山高寒草甸生命地带,但由于甘南草原生物温度明显升高,甘南草原南部和北部降水量呈现不同的变化趋势,位于青藏高原边坡地带的甘南草原的Holdridge生命地带距平均中心的偏移趋势逐年增大,甘南草原生态系统的稳定性在减弱;甘南草原潜在蒸散率以0.02/10 a～0.03/10 a趋势上升,其中以玛曲上升最明显,达0.03/10 a;20世纪90年代后,甘南草原呈明显的暖干化趋势,其中以位于南部的碌曲、玛曲变化最为明显,碌曲已由极湿润区转变为湿润区;玛曲有从极湿润区向湿润区过渡的趋势。影响甘南草原潜在蒸散率上升的主要气候因子是温度,其次为降水和空气湿度,温度上升是甘南草原暖干化的主要原因。Gannan meadow lies in the south-west of Gansu Province, on the northeast border region of Tibet Plateau. Gannan meadow is the core region of the important water source supply area of the Yellow River, which provides a natural defense for the upper reaches, playing a unique role in the water source and eco- environmental security of the Yellow River Basin. Owing to the climate change and the artificial sabotage, the production performance and ecology function of Gannan meadow shows an obvious declining trend in recent years,the grassland degeneration and deserting trend are accelerated, and the phenological of herb- age shows an obvious earlier trend. The ecology and environment of Gannan meadow has obviously changed. The Holdridge life zone system is a common used method to study the relation of the vegetative cover and climate, which has an obvious significance of physics and biology. It is widely used in the study of ecology environment, the dry and wet climate changes, the climate regionalization and so on. Most of the meadows in Gannan Plateau are distributed in Hezuo, Xiahe, Luqu and Maqu, so 4 places are selected as representative area to study the moving tendency of Holdridge life zone and dry and wet cli- mate changes of Gannan meadow. Based on the meteorological data, the method of Holdridge life zone is used to analyze the moving tendency of Holdridge life zone and the dry and wet climate changes of Gannan meadow during 1971--2010. The results show that life zone of Gannan meadow still belongs to the subal- pine meadow of Tibet Plateau alpine vegetation system. But impacted by the global climate change, the temperature of Gannan meadow increases obviously with the tendency ratio of 0. 44--0. 46~C every decade, meanwhile the bio-temperature has increased by 0. 23--0. 27~C every decade, too. The variety of precipita- tion shows a different trend between the northern and southern in Gannan meadow, the moving tendency of Holdridge life zone is diverging from the mean center, and the stability of the Gannan

关 键 词：甘南草原 Holdridge生命地带 偏移趋势 暖干化 

分 类 号：X171[环境科学与工程—环境科学]