渗漏型蒸渗仪对梭梭和柠条蒸腾蒸发的研究

利用非称量蒸渗仪对梭梭、柠条的蒸散进行了研究，结果表明：3年生的梭梭的单株蒸散量是515．3mm，3年生柠条的单株蒸散量是499．1mm。供水量和蒸散量之间存在着一定的正相关关系。3年生和2年生梭梭的单株平均蒸腾量分别是105．8mm和202.77mm；3年生和2年生柠条的单株平均蒸腾量分别为120．67mm和128．72mm。在3种供水条件下，柠条的蒸腾量都是梭梭的81％左右。在水分充足的情况下，梭梭和柠条的蒸腾量呈单峰曲线；在土壤水分亏缺的情况下，它们的蒸腾量呈双峰曲线。在干旱胁迫情况下，柠条和梭梭的蒸腾量与土壤含水率之间存在着极显著的线性关系，它们分别是:ET＝－33．29＋3217.93x（r＝0.8643）和ET＝－35．63＋1674．42x（r＝0．8273）。全年的沙面蒸发量是104.6mm-131．6mm，6－9月份的沙面蒸发量占全年沙面蒸发量的76．84％。沙面蒸发呈明显的双峰曲线。在供水条件下，沙面蒸发量随供水量的增加而增大。在无供水条件下，降水量的90．88％用于蒸发，9．12％保留于土壤中。对3年3个不同供水量蒸渗仅实测值进行多因子回归分析,得出沙面蒸发量与环境因子的关系：Ee＝－42．5131＋730．2497x1＋0．7422x2＋0．5494x3．其中Ee为月蒸发量，x1为0—40cm沙层月均含水率，x2为月均日辐射强度，x3为某月日平

A STUDY OF EVAPORTRANSPIRATION OF HALOXYLON AMMODENDRON AND CARAGANA KORSHINSKII BY DRAINAGE WATER LYSIMETERS

The evapotranspiration of Halonxylon ammodendron and Caragana korshinskii wasmeasured by drainage water lys1meter. The resu1t showed that three year old Halorylonammodendron had an amount of evapotranspiration of 515. 3 mm;three year old Cara-gana korshinskii had an amount of evapotranspiration of 499. 1 mm. There was a linearrelationship between water supply and amount of evapotranspiration. The averageamount of transpiration of 3 year old and 2 year old Haloxylon ammodendron wererespactively 105. 8 mm and 202. 77 mm. The average transpiration of 3 year old 2 yearold Caragana korshinskii were respactively 120.67 mm and 128. 72 mm. 3 differentamount of water were supplied to each species,the amount of transpiration of Caraganakorshinskii was consistently 81% of that of Haloxylon ammodendron. When the soil hadenough moisture,the amount of transpiration of Haloxylon ammodendron and Caragana korshinskii were shown as curves with single peak; When the soil lacked moisture,theamount of transpiration of Haloxylon ammodendron and Caragana korshinskii had linearrelationships with moisture content in the soil:Et= - 35. 63+ 1674. 42x(r= 0. 8237),Et= - 33. 29+ 3217. 93x(r= 0. 8463).The annual evaporation from the sand-surface was 104. 6 mm. The evaporation inthe months of June to September,accounting for 76. 84% of the annual evaporation. Theamount of evaportion from the sand-surface showed as a curve with double peaks. Thegreater the water supply,the stronger the evaporation amount from sand-surface. Whenno water was supplied, 90. 88 % of the rainfall was evaporated,about 9. 12% remained inthe soil. We discovered a linear equation between amount of evaporation and some envi-ronmental factors using the data meaured by 3 drainage water lysimeters over a 3 yearperiod: Ee = - 42. 5131 + 730. 2497x1 + 0.7422x2 + 0. 5493x3, Ee: monthly evaporationamount,x1 natural average moisture content in 0- 40 cm layer of the soil,x2 =daily aver-age sun radiation,x3:average monthly temperature.