内蒙古东部草原优势牧草生长季对气象因子变化的响应

Response of grass growing season to meteorological change in eastern Inner Mongolia grassland

研究区域气候变化对草原牧草生长的影响,对于指导农牧业生产及应对气候变化等具有重要的实践价值。基于内蒙古东部草原34个气象站50年和3个牧业气象试验站27年的气象及牧草物候期数据,研究了气候变化对优势牧草生长季的影响。结果表明:(1)研究区域年、春季、夏季和秋季平均气温均呈显著升高趋势,降水量变化春季呈微升的态势,其余时段呈微降的趋势;气候暖干化趋势明显。(2)春季气温升高有促进优势牧草返青日期提前的效应,气温每升高1℃,鄂温克旗、额尔古纳市羊草(Leymus chinensis)和贝加尔针茅(Stipa baicalensis)返青日期提前1.7～1.9d。(3)夏、秋季气温升高均有促进优势牧草黄枯日期推后的效应,气温每升高1℃,额尔古纳市羊草和贝加尔针茅黃枯日期推迟2.0～2.3d。(4)夏、秋季气温每升高1℃,额尔古纳市贝加尔针茅生长季分别延长3.3和3.7d;在巴雅尔吐胡硕秋季气温每升高1℃,冰草(Agropyron cristatum)生长季缩短2.8d。

Studying the effects of regional climate change on the grassland grasses growth is of significance for guiding local farming and animal husbandry production. Based on the 50 years observation data from 34 meteorological stations and the 27 years grass phenological data from three animal husbandry meteorological experimental stations in eastern Inner Mongolia grasslands, this paper studied the effects of climate change on the growth season of dominant grasses in the grasslands. In eastern Inner Mongolia, the mean air temperature in spring, summer, and autumn had a significant rising trend. The precipitation in spring had a slight increasing trend, but that in other seasons presented a decreasing trend. Climatic warming and drying trend was obvious. The rising of the air temperature in spring promoted the advance of the date of turning green. With an increase of 1 ℃, the turning green date of Leymus chinensis and Stipa baicalensis in Evenk and Ergun advanced 1.7-1.9 days. The rising of the air temperature both in summer and in autumn delayed the date of yellowing and withering. With an increase of 1 ℃, the yellowing and withering date of L. chinensis and S. baicalensis in Ergun postponed 2.0-2.3 days. With an increase of 1 ℃ in summer and autumn, the growth season of S. baicalensis in Ergun prolonged 3.3-3.7 days. With an increase of 1℃ in autumn, the growth season of Agropyron cristatum in Bayaertuhushuo shortened 2.8 days.