黄土高原人工植被夏季小气候日动态初步研究

Diurnal dynamics of microclimate under three forest-grass rehabilitation of artificial vegetation in Loess Plateau in summer

【目的】验证植被恢复与重建后生态环境条件的改善程度。【方法】采用定位观测的方法,以邻近裸露荒坡为对照,对典型退耕区栽植的3种类型人工植被(混交林、灌木林和草地)样地的小气候特征进行了监测,分析气温、大气相对湿度、光照强度和土壤温度、土壤湿度分布状况的日变化动态。【结果】混交林、灌木林和草地的光照强度日均值分别比对照小3.9×104,3.4×104和0.9×104lx,气温日均值分别比对照低1.53,1.32和0.51℃,表土0cm土层最高温与对照相差14.9,16.8和10.7℃;日均大气相对湿度分别比对照增加8.38%,7.34%和2.04%;光照强度、气温及其变幅的大小依次为对照、草地、灌木林、混交林,大气相对湿度及其变幅的大小排序则与之相反,土壤温度、土壤湿度及其变幅大小依次为对照、草地、混交林、灌木林;各植被类型样地内的光照强度、气温、大气相对湿度和土壤温度两两之间均存在一定的相关关系。【结论】各类型人工植被均起到了调节小气候、改善生态环境条件的作用,其中以混交林的遮光、降温、增湿等综合表现较好。

[Objective] The research was done to study the environmental effect of the Returning Farm Land into Forest and Grass-land. Three forest-grass rehabilitation of artificial vegetations in Ansai experiment station were selected to measure meteorological factors such as light intensity, wind speed, temperature,humidity,soil water content（moisture）,etc,and at the same time to make comparative observation at adjacent open sloping field（the reference）. [Method] This paper compared and analyzed the distribution characteristics and daily changes of these microclimatic parameters on different artificial vegetations. [Result] The results showed that light intensity, air temperature, and their changing amplitude followed the order of mixed forest〈shrubbery〈artificial grassland〈bare land. Air relative humidity and it＇s changing amplitude was in reverse order. Soil temperature, soil moisture and their changing amplitude went into the order of shrubbery〈mixed forest〈artificial grassland〈bare land. Compared with bare land,the diumal mean values of light intensity of mixed forest, shrubbery,grass land reduced 3.9 × 10^4 , 3.4 × 10^4 ,0.9 × 10^4 lx ,air temperature dropped 1.53,1.32,0.51 ℃ ,and the air relative humidity increased 8.38%, 7.34%, 2.04%and using the regression analysis of microclimatetic elements of different vegetation, it was learnt that there was a significant correlation between most microclimatic elements. [Conclution] Compared with the reference, the artificial vegetations have obviously regulation function in shading, dropping temperature and increasing air relative humidity, especially the mixed forest.