Needle browning and death in the flagged crown of Abies mariesii in the timberline ecotone of the alpine region in central Japan
Needle browning and death in the flagged crown of Abies mariesii in the timberline ecotone of the alpine region in central Japan
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DOI：
10.1007/s00468-012-0836-y
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发表时间：
2013-06-01
影响因子：
2.3
通讯作者：
Maruta, Emiko
中科院分区：
文献类型：
--
作者：
Nakamoto, Aoi;Ikeda, Takefumi;Maruta, Emiko
在高寒地区冬季严重胁迫形成的不对称生长旗形树冠中，万年青针叶树的针叶在早春时常褐化死亡，而在旗形树冠中则没有。针叶布朗宁和死亡被认为是由于角质层变薄或风载雪和冰粒对角质层的机械损伤而增加蒸腾作用而发生的。为了证实冷杉旗冠针叶布朗宁和死亡是否是由针叶褐变引起的，在日本高山地区符合这一概念，我们评估了机械损伤针叶角质层在林线交错带和角质层厚度对角质层阻力的影响。A.针鞘的机械损伤。未观察到玛丽氏菌。在盾形冠中，上表皮蜡质覆盖角质层并堵塞气孔前室。在旗冠，表皮蜡大多缺席。旗形树冠的表皮阻力低于旗形树冠。但旗形冠的角质层比旗形冠厚。A.旗冠的针叶布朗宁和死亡。即使针护罩没有机械损坏，也会发生mariesii。旗冠较厚的角质层可能在其他压力中发挥作用。为了估计干燥胁迫与角质层的关系，我们不仅需要阐明角质层的阻力和角质层厚度，而且角质层的质量和结构。
In the flagged crown, which is asymmetric growth formed by severe stresses during winter in alpine regions, needles of evergreen conifers often became brown and died in early spring, but did not in a cushion-shaped crown. Needle browning and death is thought to occur by increasing transpiration due to a thinner cuticle or mechanical damage to the cuticle by wind-born snow and ice particles. To confirm whether the needle browning and death in the flagged crown of Abies mariesii Mast., in the alpine region of Japan conform with this concept, we assessed mechanical damage of the needle cuticle in a timberline ecotone and evaluated the effect of cuticle thickness on cuticular resistance. Mechanical damage on needle cuticles of A. mariesii was not observed. In the cushion-shaped crown, epicuticular wax covered the cuticle and plugged stomatal antechambers. In the flagged crown, epicuticular wax was mostly absent. Cuticular resistance in the flagged crown was lower than that in the cushion-shaped crown. However, the cuticle in the flagged crown was thicker than that in the cushion-shaped crown. The needle browning and death in the flagged crown of A. mariesii occurred even though needle cuticles were not mechanically damaged. The thicker cuticle of the flagged crown may play a role in other stresses. To estimate desiccation stress in relation to the cuticle, we need to elucidate not only cuticular resistance and cuticle thickness, but also cuticle quality and structure.