低覆盖度行带式固沙林带间具有较大空间,受林带影响其带间小气候存在空间差异性。为了解其带间不同位置小气候变化特征,选取一典型低覆盖度行带式固沙林,于典型晴天对其带间距林带不同距离处太阳辐射、气温及相对湿度进行同步观测。结果表明:低覆盖度行带式固沙林具有阻挡带间太阳辐射,降低空气温度,增加相对湿度效应;林带对太阳辐射影响区域主要集中在0.5H范围内,太阳辐射强度随距林带距离增大而增加;在两侧林带影响下,气温呈现两端低,中间高的梯度变化,相对湿度呈现两端高,中间低的梯度变化。空气温湿度在垂直于林带走向方向上形成了水热势能梯度,影响带间水平方向上的水热输送及循环。
Belt- type artificial forest of low coverage has a big space between the belts,microclimate in which varied with distance from forest belt owing to forest vegetation influences. In order to know the microclimatic characteristics at different inter- belt position,we synchronously observed solar radiation,air temperature and relative humidity in a typical low coverage sand- fixing forest belt on sunny days in the growing season. The result show that low coverage sand- fixing forest belt had effects of lowing solar radiation,air temperature and increasing air relative humidity. Solar radiation affected by forest belt was mainly concentrated in the range of 0. 5times the tree height,and the intensity of solar radiation increased with the distance to forest belt; Influenced by forest belt,air temperature and relative humidity varied with the distance to forest belt,the aggregate performance was that the air temperature on both ends of forest belt was lower than that in the middle of the forest belt,and relative humidity on both ends of forest belt was much higher than in the middle of the forest belt. In the direction perpendicular to the forest belt,air temperature and humidity formed a hydrothermal potential energy gradient,which would alter the circulation and transmission way of water and heat.