Modelling variability of wood density in beech as affected by ring age, radial growth and climate

Abstract

Although it has been recognized as a key parameter of wood quality and a good source of information on growth, annual wood density has been little studied within diffuse-porous trees such as beech (Fagus sylvatica Liebl.). In this paper we examine the variability encountered in beech ring density series and analyze the influences of ring age, ring width, climate and between-tree variability on density. Thirty ring sequences were sampled from 55-year-old dominant beech trees growing within the same stand; ring density and width were measured using radiography. Ring density proved to be less variable through time than ring width. The relationship between these two variables was less than observed in ring-porous trees and it showed great variation between trees. The sensitivity of ring width and density to climate was also different; width was strongly linked to soil water deficit whereas density was correlated to temperature and August rainfall. Unlike ring width, wood density showed sensitivity towards climatic characteristics of the late growing season. A large part of annual density variability remains unexplained, even using advanced modelled water balance variables. We hypothesize that a significant part of the tree ring is under internal control. We also demonstrated great inter-tree variability (the tree effect) in ring density, which has an influence on density but not on trees' response to climate.

Xylem Phenology of <i>Fagus sylvatica</i> in Rarău Mountains (Eastern Carpathians, Romania)

“…In their studies, Cufar et al (2008a) found that about 76% of the annual ring was formed by the end of June, whilst, in similar studies in Czech Republic, the percentage reached 65% (Vavrcik et al, 2013). The results showed that June had the highest importance in the radial growth, an observation that has also been confirmed by other studies (Bouriaud et al, 2004;Michelot et al, 2012;Oladi et al, 2011). However, the maturation of cells (complete lignification process) continues even after the cessation of the cambial division (Gricar et al, 2005;De Luis et al, 2007).…”

“…Most dendroclimatological studies are based on the analysis of the statistical relationship between the width of tree rings and the climatic factors from current and previous growing seasons (Schweingruber, 1992). Only few studies addressed the problem of intra-annual variation of the treering characteristics, respectively the dynamics of beech radial growth phases (Schmitt et al, 2000;Bouriaud et al, 2004;Oladi et al, 2011;Prislan et al, 2013;Vavrcik et al, 2013).…”

Selected properties of European beech (Fagus sylvatica L.)

“…In contrast to other materials, the wood density is considerably dependent on the wood structure (ring width, the proportion and the radius of macro-and micro-vessels), the position in the stem, the location of the tree and the moisture con- -) tent (Lexa et al 1952;Trendeleburg 1955;Niemz 1993;Požgaj et al 1997;Bouriand et al 2004). Bouriand et al (2004) examined the variability of wood density within a tree ring. They found out that wood density ranged between 200 and 850 kg/m 3 and that wood density increased continually from the beginning to the end of a ring.…”

Approche dendroécologique de la sensibilité du Hêtre (Fagus sylvatica L.) au climat en France et en Europe.

“…Ainsi, la croissance augmente très rapidement de la mi-mai à juillet. Fin juin, entre 30 et 70 % de l'accroissement radial a déjà eu lieu et la croissance s'arrête entre fin août et mi-septembre (Schmitt et al, 2000 ;Barbaroux et Bréda, 2002 ;Bouriaud et al, 2003). De plus, contrairement aux Chênes pour lesquels seuls quelques cernes restent fonctionnels pour le transport de l'eau (en conditions normales), un nombre important de cernes est utilisé pour le flux d'eau chez le Hêtre, ce qui rend cette essence beaucoup moins dépendante des vaisseaux formés pendant l'année (Suzuki et al, 1996).…”