Document Detail

Reducing stem bending increases the height growth of tall pines.
MedLine Citation:
PMID:  16908504     Owner:  NLM     Status:  MEDLINE    
The hypothesis was tested that upper limits to height growth in trees are the result of the increasing bending moment of trees as they grow in height. The increasing bending moment of tall trees demands increased radial growth at the expense of height growth to maintain mechanical stability. In this study, the bending moment of large lodgepole pine (Pinus contorta Dougl. Ex Loud. var. latifolia Engelm.) was reduced by tethering trees at 10 m height to counter the wind load. Average bending moment of tethered trees was reduced to 38% of control trees. Six years of tethering resulted in a 40% increase in height growth relative to the period before tethering. By contrast, control trees showed decreased height growth in the period after tethering treatment. Average radial growth along the bole, relative to height growth, was reduced in tethered trees. This strongly suggests that mechanical constraints play a crucial role in limiting the height growth of tall trees. Analysis of bending moment and basal area increment at both 10 m and 1.3 m showed that the amount of wood added to the stem was closely related to the bending moment produced at these heights, in both control and tethered trees. The tethering treatment also resulted in an increase in the proportion of latewood at the tethering height, relative to 1.3 m height. For untethered control trees, the ratio of bending stresses at 10 m versus 1.3 m height was close to 1 in both 1998 and 2003, suggesting a uniform stress distribution along the outer surface of the bole.
Shawn X Meng; Victor J Lieffers; Douglas E B Reid; Mark Rudnicki; Uldis Silins; Ming Jin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-08-14
Journal Detail:
Title:  Journal of experimental botany     Volume:  57     ISSN:  0022-0957     ISO Abbreviation:  J. Exp. Bot.     Publication Date:  2006  
Date Detail:
Created Date:  2006-09-18     Completed Date:  2006-12-08     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9882906     Medline TA:  J Exp Bot     Country:  England    
Other Details:
Languages:  eng     Pagination:  3175-82     Citation Subset:  IM    
Department of Renewable Resources, ESB 4-42, University of Alberta, Edmonton, Alberta, Canada T6G 2H1.
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MeSH Terms
Pinus / anatomy & histology*,  growth & development*
Plant Stems / anatomy & histology,  growth & development
Stress, Mechanical

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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