Effects of Water Stress on Tissue Elasticity in Nine Tree Species  

作　　者：Li JiyueForest Resources College,Beijing Forestry University 

出　　处：《北京林业大学学报》1992年第S2期25-32,共8页Journal of Beijing Forestry University

摘　　要：The experiments were carried out under the conditions of controlled soil water potential in a greenhouse. The effects of water stress on tissue elasticity were studied in 1 - 3 year-old seedlings Pinus tabulaeformis, Platycladus orientalis, Quercus variabilis, Acer truncatum , Robinia psendoacacia, Fraxinus americana , Amorpha fruticosa, Hip-pophea rahmnoides and Cotinus coggygria ,using the pressure-volume method. Tissue elasticity was characterized using graphs of the modulus of elasticity plotted as a function of turgor pressure and maximum values of the elastic modulus. Changes in tissue elasticity may be an important characteristic allowing low water potentials to be reached and maintained without the development of detrimental water stress. The results show that tissue e-lasticity in needle-leaved tree species is higher than in broad-leaved tree species,but the modulus of elasticity of the tree species tend to increase following development of water stress. Increases in elastic modulusThe experiments were carried out under the conditions of controlled soil water potential in a greenhouse. The effects of water stress on tissue elasticity were studied in 1 - 3 year-old seedlings Pinus tabulaeformis, Platycladus orientalis, Quercus variabilis, Acer truncatum , Robinia psendoacacia, Fraxinus americana , Amorpha fruticosa, Hip-pophea rahmnoides and Cotinus coggygria ,using the pressure-volume method. Tissue elasticity was characterized using graphs of the modulus of elasticity plotted as a function of turgor pressure and maximum values of the elastic modulus. Changes in tissue elasticity may be an important characteristic allowing low water potentials to be reached and maintained without the development of detrimental water stress. The results show that tissue e-lasticity in needle-leaved tree species is higher than in broad-leaved tree species,but the modulus of elasticity of the tree species tend to increase following development of water stress. Increases in elastic modulus facilitate water uptake from drying soils, but result in greater turgor loss during tissue dehydration. In addition,the relation between the bulk tissue elastic modulus and tissue turgor pressure varied by species and varied with water stress. Although the values of the elastic modulus reported here agree in magnitude with values reported in general for higher plant tissue,the functional dependency of the apparent elasticity on tissue water status is more complex in this study than can be accounted for by current models.

关 键 词：WATER stress WATER potential TURGOR elastic MODULUS pressure-volume 

分 类 号：S[农业科学]