Abstract:

Based on the meteorological data from 1961 to 2008 of the middle arid region of Ningxia including Haiyuan county, Yanchi county and Tongxin county, the paper calculated the climate potential productivity of the grasslands in the research area using Miami Model and Thornthwaite Memorial Model. Then the study amended it with soil correction coefficient and further investigated the spatial and temporal variability characteristics of climate-soil potential productivity, so as to explore the limiting factors of grassland productivity and to provide references for local grassland production. The results were as following. Firstly, the climate in the area selected was the warm-dry-type. The average temperature clearly tended to increase, but precipitation tended to decrease with some fluctuation. Secondly, following the climate change trend the climate potential productivity decreased with fluctuation. Compared with temperature, precipitation was the limiting factor that restricted the climate potential productivity. Thirdly, according to the spatial heterogeneity of soil fertility, the grassland climate-soil potential productivity in the three counties was in the following order:Haiyuan county (3 025 kg·hm^-2·a^-1)>Yanchi county (2 993 kg·hm^-2·a^-1) > Tongxin county (2 051 kg·hm^-2·a^-1).

Key words: Climate change, Grassland, Climate-soil potential productivity, The Middle Arid Region of Ningxia

摘要：

利用宁夏中部干旱带海原、盐池、同心三个县1961年-2008年48年的气象资料，采用Miami模型和Thornthwaite Memorial模型计算了研究区草地气候生产潜力，用土壤修正系数对气候生产潜力做修正，研究了该区域气候-土壤生产潜力的时空演变特征，旨在探索影响宁夏中部干旱带草地生产力的主要限制因素，为当地的草地生产提供参考。结果表明：研究区气候呈暖干型发展趋势，温度呈显著增加趋势而降水呈波动中递减趋势；研究区气候生产力呈波动中递减趋势。与温度相比，降水是影响研究区气候生产潜力的制约因子；由于土壤肥力存在空间分异，研究区草地气候-土壤生产潜力的大小排序依次为海原县3 025 kg·hm^-2·a^-1>盐池县2 993 kg·hm^-2·a^-1>同心县2 051 kg·hm^-2·a^-1。

关键词: 气候变化, 草地, 气候-土壤生产潜力, 宁夏中部干旱带