几种植被能量平衡的差异

根据１９８９年４－１０月的观测资料,分析了晋西黄土高原地区几种主要植被之间能量平衡的差异。结果表明,不同植被间反射率差异明显,在太阳总辐射差别不大的情况下,各下垫面得的净辐射差异显著,有效辐射的差异相对较小;不同植被之间土壤热通量（Ｑｓ）、显热通量（Ｈ）、潜热通量（ＬＥ）都存在一定的差异。在潜热通量的日间变化过程中,草地和刺槐林没有“午休”现象,而油松林和沙棘林有明显的“午休”现象。刺槐林的日平均

The Differences in Energy Balance Between Several Vegetations

Based on the data observed in the growing season (Apr.to Oct.,1989),the differences in energy balance between several vegetations,dominant on the West-Shanxi Loess Plateau,were analysed and compared.It was shown that the albedo differed with vegetations.Under insignificant differences in total solar radiation, the net radiations differed from each other obviously with small differences in effective radiation.Certain differences were found in soil heat flux (Qs), sensible explicit heat nux(H) and latent heat flux(LE) between difltrent vegetations. According to the daily varying curve of latent heat flux, grass lands and locust stands had no"midday-naps",but Chinese pine sands and seabuckthorn stands had. The daily average evapotranspiration of locust stands was 0.06 mm/d more than that of Chinese pine stands. The daily average evapotranspiration of Chinese pine stands was 0.14mm/d more than that of seabuckthorn stands.The daily average evapotranspiration of seabuckthorn was 0.34mm/d more than that of grass lands and the daily average evapotranspiration of grass land was 0.36mm/d more than that of bare land. The evapotranspiration of stands was shout 1.3 times that of grass land and the evapotranspiration of grass land was aslo about 1.3 times that of bare land.