拆分典型草原群落蒸散组分方法研究

在内蒙古锡林郭勒典型草原,采用氢氧稳定同位素法和微型蒸渗仪法,分别对典型草原群落蒸散通量进行观测和拆分,以期为草原群落的蒸腾、蒸发观测方法的选择提供参考依据.结果 表明:水汽同位素组成随高度增加逐渐减小,每次较大的降雨过程都会导致水汽同位素组成显著降低.环境因素尤其是相对湿度对土壤蒸发同位素组成的计算会产生较大影响,土...

The Study on Methods of Separating Evapotranspiration Components of Typical Grassland Plant Communities

To provide basis for the selection of methods for observation of transpiration and evaporation of typical grassland plant communities,the hydrogen and oxygen stable isotope method and the micro-lysimeter method were used to observe and separate the evapotranspiration components of plant communities in the typical grassland of Xilin Gol in Inner Mongolia.The results showed that the isotopic composition of water vapor gradually decreased with the increase in altitude,and the water vapor isotopic composition was decreased significantly with each heavy rainfall.Environmental factors,especially relative humidity,have a greater impact on the calculation of soil evaporative isotope composition.Due to the isotope fractionation effect,the isotopic composition of soil water was significantly enriched compared with that of soil evaporation water vapor.From 11:30 to 14:30,the separation results of the micro-lysimeter and isotopic method were similar that the ratio of transpiration to evaporation(F T)values derived from above methods were 80.86%and 78.07%,respectively.This indicated that the water isotope method was a feasible way to separate the evapotranspiration in the grassland ecosystem.The F T value of the above two methods showed a parabolic trend from May to September,which reached the peak from the middle of July to the end of August.