准噶尔盆地南缘梭梭水分来源与传输规律分析

Water sources and transport for Haloxylon ammodendron in southern margin of Junggar Basin

基于稳定同位素及热平衡茎流测定技术对干旱区荒漠植物梭梭水分利用来源及传输规律进行了研究。结果表明:(1)雨前梭梭水分利用来源主要为地下水(贡献率34.14%)和120-180cm土层土壤水(贡献率29.87%);雨后梭梭水分利用来源主要为60-120cm土层土壤水(贡献率33.19%)和地下水(贡献率30.67%);(2)梭梭茎流呈现明显的昼夜变化规律,正午出现短暂的"午休"现象;(3)梭梭茎流速率受气候因素影响,茎流变化滞后于气象因子变化约1h;各气象因子对梭梭茎流速率影响程度为:太阳辐射(0.826)>大气温度(0.598)>湿度(-0.573)。

Based on stable isotope and heat balance stemflow measurements,the water use sources and transport patterns of Haloxylon ammodendron in arid areas were studied.The results showed that:(1)The main sources of water for H.ammodendron before rain are groundwater(contribution rate of 34.14%)and soil water(contribution rate of 29.87%)in 120-180 cm soil layer;after rain,the main sources of water for H.ammodendron are soil water(contribution rate of 33.19%)and groundwater(contribution rate of 30.67%)in 60-120 cm soil layer.(2)The stem flow of H.ammodendron is obvious.There is a short"midday break"phenomenon in the diurnal variation pattern.(3)The stem flow rate of H.ammodendron is affected by climatic factors,which lags behind the change of meteorological factors for about 1 hour.The influence degree of each meteorological factor on the stem flow rate of H.ammodendron is:solar radiation(0.826)>atmospheric temperature(0.598)>humidity(-0.573).