【摘要】 以青海云杉为主体的祁连山水源林 ,处在“冰源水库”和河川水系之间 ,具有独特的小气候作用 :林冠遮蔽使青海云杉林林内总辐射比林外减少 71 .0 2 % ,林冠层净辐射占林冠层总辐射的 5 8.0 % ,林内净辐射仅占林冠层总辐射的 1 9.0 % ;覆盖率为 40 %的青海云杉林林内1 4时平均气温低于林外 0 .4℃ ,2时平均气温高于林外 0 .1℃ ,而且森林覆盖率越高降低温度、缩小温差作用越明显 ;森林作用使林内蒸发仅为林外的 6 0 .71 % ,风速仅为林冠处的1 3.33% ,而林内年平均湿度比林外高 1 6 .6 7% ,特别是最低湿度要比林外高 5 3.5 7%。更多还原

【Abstract】 Qilian Mountain water shelter forest is dominated by Picea crassifolia, which lies in between ice source reservoir and river hydrographic net, and it has particular partial climate characteristics: firstly, because of the crown cover of Picea crassifolia, the total radiation in forest is 71.2% lower than that in open fields, the net radiation of crown laywer accounts for 58.0% of its total radiation, and the net radiation in forest only accounts for 19.0% of the total radiation of crown layer. Secondly, the mean temperature at 14 o’clock in Picea crassifolia forest of 40.0% cover rate is 0.4 ℃ lower than that in open fields, but at 2 o’clock, that is 0.1 ℃ higher, the higher of the cover rate, the more significant of the effect of dropping temperature and lowering temperature. Thirdly, the inner evaporation only accounts for 60.71% of that in open fields, wind speed accounts for 13.33% of the crown’s, whereas the inner annual mean humidity is 16.67% higher than open fields, especially the minimum humidity, is 53.57% higher than that in open fields.更多还原