Growing season sap-flow dynamics of Robinia pseudoacacia plantation in the semi-arid region of Loess Plateau, China
Aim We studied the relationship between sap-flow velocity and meteorological factors to quantitatively correlate tree growth and transpirational water-consumption, determine the dynamic change of water use of Robinia pseudoacacia in a semi-arid region, reveal its mechanism to adapt to environmental factors and provide the theoretical basis for local ecological reconstruction of the environment.Methods A thermal dissipation probe (TDP) was used to measure the sap-flow dynamics of R. pseudoacacia in Ansai County in the semi-arid region of the Loess Plateau of China during July 1-26, 2008. Soil water content, photosynthetic active radiation (PAR), air temperature, relative humidity, water vapor pressure deficit (VPD) and wind speed were measured at the same time.Important findings Diurnal variation of sap flow displayed a broadly peaked curve during the season of rapid growth. The average value was 0.001 33 cm·s~(-1). Sap-flow velocity per unit sapwood area was significantly correlated with PAR, air temperature and VPD and was negatively correlated with atmospheric relative humidity. The ranking of correlation coefficients was PAR > air temperature > VPD > relative humidity > wind speed. Sapwood area and diameter at breast height (DBH) were significantly correlated (r = 0.878), and sap-flow velocity per unit sapwood area decreased with increased stem diameter.
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NSTL
万方数据
维普
