4.7 Article

Detailed analysis of double girdling effects on stem diameter variations and sap flow in young oak trees

期刊

ENVIRONMENTAL AND EXPERIMENTAL BOTANY
卷 68, 期 2, 页码 149-156

出版社

PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.envexpbot.2009.11.012

关键词

Assimilation; Carbohydrates; Carbon transport (phloem); Growth; Source-sink relations; Sap flow

资金

  1. Research Foundation-Flanders (FWO)

向作者/读者索取更多资源

Stem diameter variations are not solely driven by the water Status of a tree, but also by the carbon Status in the phloem. We mechanically changed the carbon status in young oak trees (Quercus robur L.) by girdling the stem in order to investigate its effect on stem diameter variations. The stem was girdled at two heights by removing the bark which contains the carbon Conducting phloem. The upper stem zone (U) still received new assimilates from the leaves, while the lowest stem zone (L) received only stored carbon from the roots. The middle stem zone (M) was completely isolated from crown and roots. As downward carbon transport was interrupted after girdling, the stem expansion and the roots. We argue that expedited growth in U was driven by both irreversible radial growth and reversible swelling. In contrast to U,stem expansion and carbohydrate content decreased in the two lower stem zones (M and L). Time lags were observed between the moments of morning shrinkage when comparing the three stem zones (U. M and L). Since these time lags correlated with the soluble carbohydrate content, it seems that daily dynamics in stem diameter variations were influenced by changes in Carbon Status. Furthermore. a decrease in xylem sap flow rate was observed, which Could be attributed to an indirect effect of girdling. This decrease seems to be provoked by a feedback inhibition of net photosynthesis rate via stomatal Closure. Such feedback inhibitions are often described in literature as a consequence of the reduced sink strength after girdling. This study, hence, demonstrates that a disturbance in tree carbon status not only changes carbon-related processes (i.e. radial stem growth, photosynthesis, carbon storage), but also water-related processes (i.e. stem swelling and shrinkage, transpiration and sap How). (C) 2009 Elsevier B.V. All rights reserved.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据