高寒地区多年生禾草混播草地的生理-生态特性研究

Study on the physiological -ecological characteristics of mixture grassland of cultivated perennial grasses in alpine area

在青藏高原高寒区——天祝县金强河地区进行了多年生禾草混播草地生理—生态特性的研究 ,结果表明 ,与单播相比 ,混播可以使 0～ 2 0 cm土层的生长季≥ 0℃积温和日均温分别提高 4 0 .6℃～ 2 4 6 .7℃、0 .3℃～ 1.7℃ ;混播草地地表≥ 0℃积温和日均温增幅最大的月份为 6月 ,其余土层≥ 0℃积温和日均温增幅最大的月份均为 5月 ;与单播草群相比 ,相应的混播群落的光能利用率明显提高 (P<0 .0 5 ) ;四组分草群的光能利用率显著高于二、三组分草群 (P<0 .0 5 ) ,二组分草群和三组分草群的光能利用率间均无显著差异 (P>0 .0 5 ) ;同一环境条件下 ,单种植物叶片的光合速率和水分利用率取决于植物的种类 ,而与播种方式 (单播或混播 )无关 (P>0 .0 5 )。

Physiological-ecological characteristics of mixture grassland of cultivated perennial grasses were studied in apline area of Qinghai-Tibetan plateau, Jingqianghe area of Tianzhu county. The results indicated that the ≥0 ℃ accumulated temperature and average daily temperature of 0~20 cm soil on the mixture grassland could be promoted 40.6 ℃～246.7 ℃ and 0.3 ℃～1.7 ℃ respectively, during growing season when compared with single grassland. The peak increment of highest ≥0 ℃ accumulated temperature and average daily temperature of surface soil on the mixture grassland occured in June, and that of 5 cm, 10 cm, 15 cm and 20 cm soil on the mixture grassland occurred in May. Solar conversion efficiency (SCE) of the mixture grassland was higher than that of corresponding single grassland (P<0.05). The SCE of 4 grass species communities was higher than that of 2 and 3 grass species communities (P<0.05),and the SCE of 3 grass species communities was not statistically different from that of 3 grass species communities (P>0.05). Photosynthesis rate (Pr) and water utilization efficiency (WUE) of leaves were highly related to the grass species, not related to the sowing patterns, mixture or single.