Leaf water relations of Eucalyptus globulus ssp. globulus and E. nitens: seasonal, drought and species effects.
Leaf water relations of Eucalyptus globulus ssp. globulus and E. nitens: seasonal, drought and species effects.
复制标题
蓝桉叶水关系。
DOI：
10.1093/treephys/16.5.469
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发表时间：
1996
期刊：
影响因子：
4
通讯作者：
D. Worledge
中科院分区：
文献类型：
--
作者：
D. A. White;D. A. White;C. Beadle;C. Beadle;D. Worledge
1990年8月，在降雨量（年约515毫米(-1)）不足以满足蒸发需求的地区建立了2公顷的种植园。 1991 年 9 月至 1993 年 4 月期间，九次为灌溉和雨养的蓝桉构建了压力-体积曲线。球状拉比尔。和 E. nitens (Deane 和 Maiden) 处女树。在实验过程中，雨养树木经历了六个黎明前水势显着低于灌溉树木的时期。 1991年和1992年早春，灌溉的E. nitens在完全膨压点和膨压损失点的渗透势明显低于一年中的其他时间，可能是由于冬季硬化的缘故。水胁迫降低了黑桉的渗透势并增加了体积弹性模量，而蓝桉则相反。然而，渗透和弹性特性变化方面的处理差异通常被种间差异所掩盖。这些在水分胁迫的第六期结束时最为明显，此时蓝桉的渗透势在完全膨胀和零膨胀时显着较高，而膨胀损失点的体积弹性模量和相对含水量显着低于黑桉。我们得出的结论是，E. globulus 的耐旱反应使其成为比 E. nitens 更适合在遭受中等水分胁迫的地区定居的物种。
In August 1990, a 2-ha plantation was established in an area where rainfall (about 515 mm year(-1)) was insufficient to meet evaporative demand. On nine occasions between September 1991 and April 1993, pressure-volume curves were constructed for irrigated and rainfed Eucalyptus globulus ssp. globulus Labill. and E. nitens (Deane and Maiden) Maiden trees. During the experiment, rainfed trees experienced six periods when predawn water potential was significantly lower than that of irrigated trees. In early spring of 1991 and 1992, osmotic potentials at full turgor and turgor loss point in the irrigated E. nitens were significantly lower than at other times of the year, probably because of winter hardening. Water stress reduced osmotic potential and increased bulk elastic modulus in E. nitens, whereas the reverse occurred in E. globulus. However, treatment differences with respect to changes in osmotic and elastic properties were commonly overshadowed by interspecific differences. These were most apparent at the end of the sixth period of water stress when osmotic potentials at full and zero turgor were significantly higher and bulk elastic modulus and relative water content at turgor loss point were significantly lower in E. globulus than in E. nitens. We conclude that the drought-tolerance responses of E. globulus make it a more suitable species than E. nitens for establishment on sites where moderate water stress is experienced.