青海牧草对气候变化的响应

Response of Herbage to Climate Change in Qinghai

为更好地了解气候变化对牧草的影响,采用线性趋势法和相关性分析,研究青海牧草的高度、覆盖度、产量、返青期和黄枯期以及影响因子。结果表明,6—8月牧草的高度和覆盖度均以不同的速率呈上升趋势,6月和7月的牧草产量以不同的速率呈增产趋势,8月的牧草产量呈减产趋势。返青期以0.65 d/10 a的速率提前,枯黄期以0.15 d/10 a的速率推迟,牧草生长期延长;其中班玛、甘德、久治、玛沁、海晏、清水河、天峻和同德地区的牧草生长期延长,其他地区的牧草生长期缩短。冬季气温、6月下旬气温和8月风速是影响沱沱河地区牧草的主要因子;9月蒸发、秋季最低气温和6月≥10℃的积温是影响甘德地区牧草的主要因子;气温、2月0 cm地温和9月≥0℃的积温是影响天峻地区牧草的主要因子。

Based on linear trend analysis and correlation analysis,we studied the height,coverage,yield,turning green period and yellow withering period of herbage and the influencing factors of climate change on herbage in Qinghai.The results show that the height and coverage of forages increase at different rates from July to August,the herbage production increases at different rates in June and July.The herbage production presents a decreasing trend in August.The rejuvenation period is advanced at a rate of-0.65 d/10 a.The yellow withering period is delayed at the rate of 0.15 d/10 a.The growth period of herbage is prolonged.In Banma,Gande,Jiuzhi,Maqên,Haiyan,Qingshuihe,Tianjun and Tongde,the growing period of herbage is extended,and in other areas,the growing season is shortened.Winter temperature,temperature in late June and wind speed in August are the main factors influencing herbage in the Tuotuo River area.Evaporation in September,the minimum air temperature in autumn and the accumulated temperature in June≥10℃are the main factors affecting herbage in Gande area.The air temperature,the ground temperature of 0cm in February and the accumulated temperature of≥0℃in September are the main factors affecting the forage in Tianjun area.