充分灌溉下毛白杨树干直径变化对气象因子的响应

Variations of Triploid Populus tomentosa Tree Trunk Diameter Fluctuate under Full Irrigation and Its Relation to Meteorological Factors

以三倍体毛白杨为试验对象,在控制土壤水势不低于-25kPa的充分灌溉条件下,研究了树干直径变化指标与气象因子的关系。对树干直径日最大收缩量(MDS)产生主要影响的气象因子有参考作物蒸腾蒸散量(ET0)、饱和水气压差(VPD)、日平均温度(Tmean)、日最高温度(Tmax)、日最低温度(Tmin)、空气相对湿度(RH)、太阳辐射(Rn),其中与ET0、Rn呈极显著正相关,与Tmin、RH、VPD极显著负相关,与Tmax呈显著正相关;树干直径日增长量(DG)主要受Rn的影响,影响树干直径日最大值(MXTD)、树干直径日最小值(MNTD)的气象因子主要是3个温度指标:Tmean、Tmax、Tmin。MDS可以反映大气干旱程度。温度是影响树干直径增长的重要气象指标。

Taking triploid Populus tomentosa as the research object, the relationships between the changes of trunk diameter and meteorological factors were examined under fully irrigated conditions（ the soil water potential was no less than -25 kPa）. The meteorological factors that mainly affected the maximum daily trunk shrinkage （MDS）included reference crop evapotranspiration （ETo）, vapour pressure deficiency（VPD）, daily mean temperature （Tmean）, daily maximum temperature （Tmax）,daily minimum temperature（Tmin）, relative humidity （RH）, and solar radiation （Rn）. It was observed that MDS was very significantly and positively correlated with Rn and ET0 very significantly and negatively correlated with Tmin, RH, andVPD, significantly correlated with Tmax. The daily diameter gain （DG）was mainly affected by Rn. Three meteorological indices that affected maximum daily trunk diameter （MXTD）and minimum daily trunk diameter （MNTD）were Tmean, Tmax, and Tmin. MDS could indicate atmospheric drought conditions. Temperature was an important meteorological indicator of influencing the growth of trunk diameter.