Vertical foliage distribution determines the radial pattern of sap flux density in Picea abies
Vertical foliage distribution determines the radial pattern of sap flux density in Picea abies
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DOI：
10.1093/treephys/28.9.1317
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发表时间：
2008-09-01
期刊：
影响因子：
4
通讯作者：
Cescatti, Alessandro
中科院分区：
文献类型：
--
作者：
Fiora, Alessandro;Cescatti, Alessandro
了解决定树液通量密度径向模式的原因对于提高边材功能的知识和扩大树冠蒸腾和生态系统水分利用的树干流量测量都是重要的。为了研究轮生和一年生边材年轮之间的解剖联系，用Granier探针监测了修剪引起的35年生云杉(Picea abies(L.)被修剪在树冠前面的喀斯特树。树干液流密度径向模式的变化通过形状指数(SI)来量化，该指数随内外边材对树木蒸腾作用的相对贡献而变化。在自下而上修剪过程中，SI逐渐减小，表明内边材对树干液流的贡献显著降低。结果表明，树干液流密度的径向分布主要取决于树冠下部树叶的垂直分布，树冠下部遮荫树枝与内边材水力相连，翻车树枝与外轮相连。
Understanding the causes determining the radial pattern of sap flux density is important both for improving knowledge of sapwood functioning and for up-scaling sap flow measurements to canopy transpiration and ecosystem water use. To investigate the anatomical connection between whorls and annual sapwood rings, pruning-induced variation in the radial pattern of sap flux density was monitored with Granier probes in a 35-year-old Picea abies (L.) Karst tree that was pruned front the crown bottom up. Modifications in the radial pattern of sap flux density were quantified by a shape index (SI), which varies with the relative contribution of the outer and inner sapwood to tree transpiration. The SI progressively diminished during bottom up pruning, indicating a significant reduction in sap Flow contribution of the inner sapwood. Results suggest that the radial pattern of sap flux density depends mainly oil the vertical distribution of foliage ill the crown, with lower shaded branches hydraulically connected with inner sapwood and tipper branches connected with the outer rings.