亚高山草甸类草地牧草生长发育与气象条件的关系研究

利用亚高山草甸类草地牧草生长发育定位观测资料和对应气象观测资料，分析牧草生长发育与气象条件的关系，结果表明，研究区域主要禾本科牧草返青到籽实成熟需140～150 d，≥0 ℃积温1 000～1 200 ℃，降水量400～450 mm，日照时间1 000～1 100 h；牧草在返青后64 d开始，由缓慢生长转为迅速生长阶段，在返青后的第88天，生长速度最快。返青后112 d开始，其生长从迅速生长又转为缓慢生长。气温对牧草产量形成在返青到抽穗期、枯黄期为正效应，其中，拔节到抽穗期、籽实成熟期牧草产量形成对气温变化十分敏感；降水量对牧草产量形成除籽实成熟期为负效应外，其余时段均为正效应，在禾本科牧草分蘖拔节期牧草产量形成对降水量变化十分敏感。日照时间对牧草产量形成影响在返青到分蘖期、籽实成熟期到黄枯期为正效应，拔节到开花期为负效应；抽穗期牧草产量形成对日照时间变化十分敏感。

Study on the relationship between grass growth and meteorological conditions in subalpine meadow

By using the observed data related to grass growth and meteorological conditions in the subalpine meadow, the relationship between grass growth and meteorological conditions were analyzed. The results showed that the growth period from re greening to ripeness was 140 to 150 days, the requirement of accumulated temperature above 0 ℃ was about 1 000 to 1 200 ℃, the requirement of precipitation was about 400 to 450 mm, the requirement of sunshine duration was about 1 000 to 1 100 hours. The growth rate of grassed reached the highest on 88th day after re greening and slowed down after 112 days. The effect of temperature on grass yield was positive from re greening to heading and withering stages and it was sensitive in the jointing, heading and ripening stages. The effect of precipitation on grass yield was positive except in ripening stage and it was sensitive in tillering and jointing stages. The effect of sunshine duration on grass yield was positive in tillering, ripening and withering stages and it was sensitive in heading stage.