合作、玛曲草甸禾本科牧草黄枯与气象因子的关系分析

The relationship analysis between the meteorological factors and the withering period of gramineous herbage at the Hezuo-Maqu meadow

利用甘南合作、玛曲农业气象观测站禾本科牧草观测资料及同期的降水、气温、日照时数等气象资料,分析了气象因子对合作、玛曲亚高山草甸禾本科牧草黄枯的影响。分析发现,合作、玛曲牧草黄枯期均有提前的趋势,提前趋势分别为每10年5.5和2.0 d,特别是1994年后,合作地区牧草黄枯期出现了明显提前的趋势。甘南高原牧草黄枯主要受热量条件限制,5℃终日是影响甘南高原牧草黄枯的主要因子,合作日平均气温5℃终日有提前的趋势;同时影响合作牧草黄枯期提前的气象因子还有夏季降水量的减少,而与玛曲牧草黄枯期提前有关的气象因子则与9月份气温升高、初秋降水量减少和9月份日照时数增加密切相关。

Based on the observed data of herbage growing and meteorological factors such as contemporaneous precipitation,atmospheric temperature and sunshine hours of Hezuo and Maqu,the effects of meteorological factors on the herbage withered date were studied in this paper.The results showed that the withered date of gramineous herbage at the Hezuo-Maqu meadow had an earlier trend with the tendency ratio of 5.5 d/10 a,2.0 d/10 a;especially after the end of 1990s,the withered date of gramineous herbage at Hezuo showed an obvious earlier trend than before.Heat condition had an important impaction to the withered date of gramineous herbage at the Gannan plateau,the most important factor was the end date of 5 ℃,there was an advancing trend in the end date of 5 ℃ of Hezuo.In addition,the decrease precipitation of summer was another main factor to affect the earlier trend of gramineous herbage withering in Hezuo meadow.The another main factors to affect the earlier trend of the Maqu meadow＇s gramineous herbage withering were increase of the temperature and sunshine hour,the decrease precipitation in September.