毛乌素沙地牧草防护林小气候效应的研究

Microclimate Effects of Pasture Shelter Belts in Maowusu Sandy Area

采用自动气象观测系统于2004年4—8月对内蒙古毛乌素沙地新疆杨牧草防护林内风速(V)、净辐射(Rn)、空气温度(Ta)及相对湿度(RH)等小气候要素进行多点连续观测和分析,以期为毛乌素沙地牧草防护林的构建提供一些理论依据.研究结果表明,随着测点与林带距离的增加,防护林内风速和空气温度呈现"倒抛物线"型变化趋势,净辐射和空气相对湿度呈现"抛物线"型变化趋势.与旷野相比,防护林内平均风速降低了12.19%,且越是大风天气,林带的防风效应越明显,净辐射减少了28.25%,空气温度增加了4%,空气湿度增加了7.81%.

Continuous observations of air temperature,relative humidity,net radiation and wind speed were conducted with auto-micrometeorological observation system in pasture shelter belts of Populus bolleana Lauche growing in Maowusu Sandy Area, Inner Mongolia. The experiment was conducted from April to August in the year of 2004. The results were as follows： In the shelter belt, wind speed and air temperature was demonstrated with tendency of ＂invert-parabolic curve＂, while net radiation and relative humidity was demonstrated with tendency of ＂parabolic curve＂. That is,the further distance it is from the shelter belts,the smaller wind speed and air temperature is; the further distance it is from the shelter belts, the more net radiation and relative humidity is. Compared with the open field, the wind speed and net radiation decreased by 12.19 % and 28.25 %,respectively. What＇s more,the wind-protective effect was obvious on typical windy days. The air temperature and relative humidity in shelter belts increased by 4.00 % and 7.81%,respectively.