Temporally resolved intra-annual wood density variations in European beech (Fagus sylvatica L.) as affected by climate and aspect

Abstract

We investigated the temporal variability of intra-annual wood den- sity variations in European beech (Fagus sylvatica L.) in a valley in south- western Germany. Samples were collected from 11 beech trees growing at north-west (NW) and south-west (SW) exposed slopes. High-frequency den- sitometry was used to obtain wood density profiles. We converted radial positions within these profiles to a seasonal time scale over automatic point dendrometer data for the period 2001-2006. Temporally resolved wood den- sity data was analyzed both visually and statistically, using correlation anal- ysis and multiple linear regressions. Water availability was found to be of major importance for wood formation. Further, our results suggest that cli- matic forcing of wood density is not necessarily restricted to the late grow- ing season only, but that strong associations may exist during a major part of the growing season. Combining wood property data with point dendrometer measurements was demonstrated to be valuable for increasing the understand- ing on the effects of changing environmental conditions on wood formation. Keywords point dendrometer, wood formation, water availability, vessel size Authors. Ernst van der Maaten (Ernst.van-der-Maaten@iww.uni-freiburg.de) - Marieke van der Maaten-Theunissen, Heinrich Spiecker - Institute for For- est Growth, Albert-Ludwigs-University, Tennenbacher Str. 4, 79106 Freiburg, Germany.