Xylem adjustment of sessile oak at its southern distribution limits
Xylem adjustment of sessile oak at its southern distribution limits
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DOI：
10.1093/treephys/tpx036
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发表时间：
2017-07
期刊：
影响因子：
4
通讯作者：
E. Martínez‐Sancho;I. Dorado-Liñán;I. Heinrich;G. Helle;A. Menzel
中科院分区：
文献类型：
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作者：
E. Martínez‐Sancho;I. Dorado-Liñán;I. Heinrich;G. Helle;A. Menzel
干旱是地中海盆地树木生长的一个关键限制因素。然而，通过木质部性状驯化的变异性在很大程度上是未知的。本文研究了不同立地条件下的栎属（Quercus petraea（Matt.）莉布分布在南欧的五个边缘地带树轮宽度（TRW），平均早材导管面积（MVA）和早材导管数量（NV）以及理论导水率（Kh）年表是在1963-2012年期间开发的。夏季干旱信号TRW年表之间是一致的，但是，船舶功能的气候响应有很大的不同网站。在这三个干旱地区，前一年的夏季干旱对MVA产生了负面影响，对NV产生了正面影响。相比之下，在两个梅西奇网站，今年的春旱负面影响NV，而MVA施加积极的影响。在这两种情况下，Kh没有改变这种木质部的调整。所有变量显示相同的东西地理模式的增长和解剖特征。无柄橡树以不同的方式应对干旱：在干旱的网站和不利的前一个夏天的条件后，更多的，但较小的船只建成，降低对空化的脆弱性，而在mesic网站，干泉部分导致树木年轮更广泛，但更少的船只。船舶相关功能的变化显示了类似的地理偶极子在地中海盆地以前描述的树木生长的其他研究。
Drought is a key limiting factor for tree growth in the Mediterranean Basin. However, the variability in acclimation via xylem traits is largely unknown. We studied tree growth and vessel features of Quercus petraea (Matt.) Lieb. in five marginal stands across southern Europe. Tree-ring width (TRW), mean earlywood vessel area (MVA) and number of earlywood vessels (NV) as well as theoretical hydraulic conductivity (Kh) chronologies were developed for the period 1963-2012. Summer drought signals were consistent among TRW chronologies; however, climatic responses of vessel features differed considerably among sites. At the three xeric sites, previous year's summer drought had a negative effect on MVA and a positive effect on NV. In contrast, at the two mesic sites, current year's spring drought negatively affected NV, while exerting a positive influence on MVA. In both cases, Kh was not altered by this xylem adjustment. All variables revealed identical east-west geographical patterns in growth and anatomical features. Sessile oak copes with drought in different ways: at xeric sites and after unfavourable previous summer conditions more but smaller vessels are built, lowering vulnerability to cavitation, whereas at mesic sites, dry springs partly lead to tree-rings with wider but fewer vessels. The variability of vessel-related features displays a similar geographical dipole in the Mediterranean Basin previously described for tree growth by other studies.