Hinckley T M, Duhme F, Hinckley A R, Richter H
College of Forest Resources, University of Washington, 98195, Seattle, WA, USA.
Research Associate, Lehrstuhl für Landschaftsökologie, Techn. Univ. München, D-8050, Freising, Germany.
Oecologia. 1983 Sep;59(2-3):344-350. doi: 10.1007/BF00378860.
Relatively static factors such as depth of rooting and cuticular conductance and relatively dynamic factors such as stomatol control and changes in the components of water potential were used to assess the drought resistance characteristics of six deciduous shrub species. Predawn water potential during a prolonged drought averaged-2.13 and-3.51 MPa in species known to have deep and shallow patterns of rooting, respectively. It is thus surprising that the osmotic potential at the turgor loss point averaged only-3.01 MPa in the shallow rooted group. The water potential at which irreversible cell damage occurred was the same in both groups (-4.9 MPa), and minimum values observed in the field never dropped below-4.0 MPa. There was, however, a pronounced difference between the two groups with regard to stomatal behavior. This allowed us to characterize the deep-rooted species as avoiders of stress which would cause prolonged stomatal closure whereas the shallow-rooted species had to tolerate prolonged periods of closed stomata.
利用相对静态的因素（如根系深度和角质层导度）以及相对动态的因素（如气孔控制和水势组成成分的变化）来评估六种落叶灌木物种的抗旱特性。在长期干旱期间，已知具有深根系和浅根系模式的物种，其黎明前水势平均分别为-2.13和-3.51兆帕。因此，令人惊讶的是，浅根系组在膨压丧失点的渗透势平均仅为-3.01兆帕。两组中发生不可逆细胞损伤时的水势相同（-4.9兆帕），且在田间观察到的最小值从未低于-4.0兆帕。然而，两组在气孔行为方面存在明显差异。这使我们能够将深根系物种表征为能够避免导致气孔长期关闭的胁迫的物种，而浅根系物种则必须忍受气孔长期关闭的情况。
