干旱荒漠区银白杨树干液流动态

应用热扩散式树干茎流计(TDP)于2012年7月1日至7月25日,在克拉玛依地区农业开发区对银白杨(Populus alba L.×P.talassica)人工林树干液流速率进行了连续测定,并对气象、土壤水分等指标进行了同步测定。结果表明:7月份的晴天银白杨树干液流速率日变化呈单峰型,阴天呈多峰型,在测量时期液流速率日平均值为0.6059 L/h;银白杨树干单位边材面积的液流速率与太阳总辐射、大气温度、水汽压差呈极显著正相关关系,与相对湿度呈负相关关系。其相关系数绝对值顺序为太阳总辐射>大气温度>水汽压差>相对湿度>风速;银白杨边材面积与胸径之间存在着显著的线性相关关系,相关系数为0.834,单位边材面积的液流速率随树干胸径的增大而减小。

Sap flow dynamics of Populus alba L.×P.talassica plantation in arid desert area

A thermal dissipation probe (TDP) was used to measure the sap flow dynamics of Populus alba L.×P.talassica in the agricultural development zones of Karamay during July 1-25, 2012.Soil mositure, total radiation (TR), air temperature, relative humidity, water vapor pressure deficit (VPD) and wind speed were measured at the same time.The results showed that: Diurnal variation of the sap flow displayed a single peaked curve on sunny days, while it displayed a multi-peaked curves on cloudy days.The average value of sap flow was 0.6059 L/h.Sap flow velocity per unit sapwood area was significantly correlated with TR, air temperature, and VPD and was negatively correlated with atmospheric relative humidity.The ranking of correlation coefficients was TR>air temperature>VPD>relative humidity>wind speed.Sapwood area and diameter at breast height (DBH) were significantly correlated (r=0.834), and the sap-flow velocity per unit sapwood area decreased with increasing stem diameter at breast height (DBH).