Chin J Plant Ecol ›› 2012, Vol. 36 ›› Issue (6): 483-490.DOI: 10.3724/SP.J.1258.2012.00483

• Research Articles • Previous Articles     Next Articles

Simulating responses of leaf stomatal conductance to environmental factors for Tamarix ramosissma in an extreme arid region of China

YU Teng-Fei1, FENG Qi1,2,*(), SI Jian-Hua2   

  1. 1Research School of Arid Environment & Climate Change, Lanzhou University, Lanzhou 730000, China
    2Alashan Desert Eco-hydrology Experimental Research Station, Cold and Arid Region Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2011-11-09 Accepted:2012-03-27 Online:2012-11-09 Published:2012-06-04
  • Contact: FENG Qi

Abstract:

AimsStomata play a key role in plant adaptation to changing environmental conditions and environmental stress because they control both water losses and CO2 uptake.
Methods Based on observation of leaf gas exchange parameters of Tamarix ramosissma in an extreme arid region in northwest of China, the relative humidity (hs) (or vapor pressure deficit (Ds)) of the BWB and BBL model were evaluated by introducing diagnosis function f(H). After that, the results were imported into the Ye and Yu mechanism model for simulation of stomatal conductance (gs) of T. ramosissma.
Important findings A significant difference was found for hs (or Ds) of the BWB and BBL model with R2 of 0.5354 and 0.1103, respectively, and the gs is significantly related to hs and Ds with a Gauss model with R2 of 0.593 and 0.258, respectively. It suggests that the relationship between gs and hs is closer than Ds. Both the simplified model (referred to Simple model) proposed by Ye and Yu and its correction (referred to Gauss-h model) behaved well with R2 of 0.8707 and 0.8286 and η of 0.1245 and 0.0171 (range from 0 to 1), respectively. The model validation shows that the Gauss-h model clearly underestimated the observations more than the Simple model, and the performance of the Simple model was significantly improved (R2 of 0.9606) when the observed condition was close to the hypothesis of model infinitely.

Key words: BBL model, BWB model, mechanism model, stomatal conductance, Tamarix ramosissma