青海湖2种高寒嵩草湿草甸湿地生态系统水热通量比较

基于涡度相关技术,研究了2015年青海湖2种高寒嵩草湿草甸湿地生态系统水热通量的特征。结果表明:(1)2015年青海湖高寒藏嵩草和小嵩草湿草甸湿地生态系统日平均水汽通量分别为1.74,0.99mm,年水汽通量分别为633.3,362.1mm。(2)青海湖2种高寒嵩草湿草甸湿地生态系统感热、潜热和净辐射日变化均呈单峰曲线,感热和潜热月平均日变化最大值出现的时间均晚于净辐射。藏嵩草湿草甸湿地生态系统感热月均日变化最大值最大为179.06W/m~2,最小为46.02W/m~2;潜热最大为312.55W/m~2,最小为30.58 W/m~2;小嵩草湿草甸湿地生态系统感热月均日变化最大值最大为161.86 W/m~2,最小为31.60 W/m~2;潜热最大为215.44 W/m~2;最小为14.08 W/m~2。(3)通过波文比分析发现,2种高寒嵩草湿草甸湿地生态系统生长季能量分配以潜热为主,非生长季小嵩草湿草甸湿地生态系统能量分配以感热为主,藏嵩草湿草甸湿地生态系统则较为复杂。藏嵩草湿草甸湿地生态系统全年能量平衡率为0.82,小嵩草湿草甸湿地生态系统为0.89,增加土壤热通量项能改善能量平衡状况。

Comparative Study on Hydrothermal Fluxes of Two Alpine Kobresia Wet Meadow Wetland Ecosystems in Qinghai Lake

Based on the eddy covariance technique,the characteristics of water and heat fluxes of two alpine wet meadow wetland ecosystems in Qinghai Lake were studied in 2015.Results showed as follows:(1) The average daily water vapor fluxes of alpine Kobresia tibetica and Kobresia humilis wet meadow wetland ecosystems were 1.74 mm and 0.99 mm,respectively,and the annual water vapor fluxes were 633.3 mm and 362.1 mm,respectively,in Qinghai lake 2015.(2) The diurnal variation of sensible heat,latent heat and net radiation all showed a single peak curve in two kinds of alpine Kobresia wet meadow wetland ecosystems,the diurnal variation maximum value of the sensible heat and latent heat occurred later than the net radiation.The maximum value of the diurnal variation of the sensible heat was 179.06 W/m2 and the minimum was 46.02 W/m2;the maximum value of latent heat was 312.55 W/m2 and the minimum was 30.58 W/m2,in K.tibetica wet meadow wetland ecosystem.The maximum value of diurnal variation of the sensible heat was 161.86 W/m2 and the minimum was 31.60 W/m2;the maximum value of latent heat was 215.44 W/m2 and the minimum was 14.08 W/m2,in K.humilis wet meadow wetland ecosystem.(3) Through the analyse of bowen ratio:the energy distribution of two alpine Kobresia wet meadow was mainly latent heat in growing season;in the non-growing season the energy distribution of K.humilis wet meadow wetland ecosystem was dominated by sensible heat,K.tibetica wet meadow wetland ecosystem was more complex.The annual energy balance rate of K.tibetica wet meadow wetland ecosystem was 0.82,and the K.humilis wet meadow wetland ecosystem was 0.89,and the increase of soil heat flux item can improve the energy balance.