Authors: Reza Oladi Achim Bräuning Kambiz Pourtahmasi
Publish Date: 2013/12/31
Volume: 28, Issue: 2, Pages: 493-502
Abstract
Water conduction in broadleaved trees depends mainly on the size number and arrangement of vessels which vary from year to year in response to varying exogenous factors thus contributing to a safe and/or efficient water transport However the nature of such compensation is not clear in particular it is not obvious which traits act independently and which ones coincidentally To better understand these interrelations treering width TRW vesselrelated anatomical traits and the theoretical hydraulic conductivity were measured or modeled in the last 50 growth rings of mature Oriental beech trees growing at different altitudes in northern Iran The study trees followed similar strategies compensating the effects of external factors by modifying their vesselanatomical features TRW and the number of vessels per unit of area were highly but negatively correlated and both were affected by exogenous factors However a decrease in vessel frequency VF is not a mirror effect of wider tree rings but trees actively control the number of vessels produced Principal component analysis revealed that the features VF TRW and relative total conductivity were more plastic whereas average vessellumen area treering porosity and relative specific conductivity behaved more static Moreover we suggest that in theoretical approaches total hydraulic conductivity rather than the specific hydraulic conductivity is a better indicator of a tree’s hydraulic behavior in a given growing season
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