Leaf water relations of competitive Fagus sylvatica and Quercus petraea trees during 4 years differing in soil drought
Leaf water relations of competitive Fagus sylvatica and Quercus petraea trees during 4 years differing in soil drought
复制标题
不同土壤干旱条件下竞争性水青冈和栎树4年叶水关系
DOI：
10.1139/x99-205
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发表时间：
2000
影响因子：
2.2
通讯作者：
C. Leuschner
中科院分区：
文献类型：
--
作者：
K. Backes;C. Leuschner
在德国西北部潮湿的土壤干旱强度低、中、高的四个季节，比较了竞争性成熟水青冈属和栎属树木的叶水关系。叶电导率（gl）通常高约30%，在栎比山毛榉太阳叶。两种植物黎明前的叶水势和渗透势非常相似。山毛榉有显着降低叶组织弹性（EMAX）比栎在干燥，但不是在潮湿的夏天。水分状况参数的年际变化较大，为GL和季节性散装叶膨压（P）最小值;中等的EMAX和每日水势（EXP）最小值;和小的EXP，EXP，和相对叶含水量在零膨压。水青冈对水分损失的调节较为保守，在湿润或中度干旱季节，水青冈对P和CO2的调节作用有限，而在偶尔严重干旱时，水青冈对CO2、Gl、光合作用和生长的调节作用较大。栎属表现出较低的Emax、较低的干旱敏感性气孔调节和明显的干旱诱导的渗透调节等胁迫耐受性物种的模式。在温带湿润环境中，树木水分关系应至少研究三到四个季节，以解释水分状况参数的年际变化。简历：在过去的五年中，我们比较了山毛榉和栎属植物的成熟枝叶之间的关系。在德国西北部潮湿的地区，这些树木在竞争条件下占有重要的地位，它们的强度、模式和强度都是不可能的。镧电导
Leaf water relations of competitive mature Fagus and Quercus trees were compared during four seasons with low, moderate, or high soil drought intensities in humid northwestern Germany. Leaf conductances (gl) typically were higher by about 30% in Quercus than in Fagus sun leaves. Predawn leaf water potentials (Ψpd) and osmotic po- tentials (Πo, Πp) were remarkably similar for the two species. Fagus had significantly lower leaf tissue elasticities (emax) than Quercus in dry but not in wet summers. Interannual variabilities in water status parameters were large for gl and seasonal bulk leaf turgor (P) minima; moderate for emax and daily water potential (Ψ) minima; and small for Πo, Πp, and the relative leaf water content at zero turgor. Fagus regulated water loss conservatively with only limited re- ductions in P and Ψ in wet or moderately dry seasons but large decreases in Ψpd, gl, photosynthesis, and growth during occasional severe droughts. Quercus displayed patterns of a stress-tolerating species (lower emax, a less drought- sensitive stomatal regulation, and apparently significant drought-induced osmotic adjustment). In temperate humid envi - ronments, tree water relations should be studied for at least three or four seasons to account for large interannual variabilities in water status parameters. Resume : Pendant quatre saisons de croissance, nous avons compare les relations hydriques du feuillage d'arbres matu- res des genres Fagus et Quercus. Ces arbres etaient places en conditions de competition et soumis a des intensites faible, moderee et elevee d'assechement du sol, dans une region humide du nord-ouest de l'Allemagne. La conductance