不同抚育处理下沙柳新生枝茎流动态及其气象主控因子

摘要

针对生长3年以上的成过熟沙柳灌丛,研究了不同采伐抚育模式下沙柳新生枝条液流的变化规律及其与气象因子的关系.研究结果表明:沙柳在不同抚育强度下的茎流日变化均呈现"几"字型规律;两种模式下各气象因子对沙柳茎流速率影响的大小顺序是:太阳辐射>大气温度>空气相对湿度>风速,其中太阳辐射对各抚育强度的影响程度为A3>A2>A1>CK,其余气象因子对茎流影响程度在不同抚育模式和强度下表现出不同规律性;在两种抚育模式下,A3(0.7 M)抚育强度处理时茎流与气象因子逐步回归拟合关系较好,在各月中R2均大于0.7,最大值出现在4月B1模式下:R2=0.906.逐步回归方程中太阳辐射是关键因子;不同抚育强度对沙柳蒸腾的促进程度不同,且在A3B1处理下对沙柳茎流速率提升效果最为明显,可有效缓解沙柳枝条之间的水分竞争压力,从而使沙柳新生枝的生长更为旺盛.%Aiming at mature and overmaturesalixbushwood over three years,the change rule of the stem flow dy-namic state and the relation of weather main-control factors of the salix innovation given various tending treatment was studied.The results showed that the changes of the stem flow in the different tending intensity showed the font of"几"patterns;The order that various meteorological factors influenced the stem flow rate of salix from large to small was solar radiation,atmospheric temperature,relative air humidity and wind speed in turn, which the inci-dence that solar radiation influenced various tending intensity from large to small was A 3,A2,A1and CK in turn, the rules that the rest meteorological factors influenced the stem flow rate shown different under various tending pat -tern and intensity.Under two kinds of tending pattern,when the treatment intensity is A 3(0.7 M), the stepwise regression matching relation between the stem flow and meteorological factors was preferably(R2>0.7),the high-est R2=0.906,and the solar radiation was the key factor in the regression equation.The degree that various tend-ing intensity promoted transpiration of salix was different,and the effect that stem flow rate rise was most obviously in the treatment of A3B1,which can effectively relieve the pressure of water competition between the salivary bran-ches,so that the growth of new branches of salix more exuberant.