This volume contains extended abstracts from talks and posters presented at the fifth TRACE (Tree Rings in Archaeology, Climatology and Ecology) conference that was held in Tervuren (Belgium) between April 20 to 22 of 2006. The annual TRACE conferences seek to strengthen the network and scientific exchange of scientists and students involved in the study of tree rings. This annual conference is an initiative of the 'Association for Tree-Ring Research' (ATR). One goal of this conference is to give young scientists and students the opportunity to present concepts, ongoing and finished work. The conference was hosted by the Laboratory of Wood Biology & Xylarium of the Royal Museum for Central Africa and the Laboratory of Wood Technology of Ghent University. The organizers were pleased to welcome an international group of 90 scientists and students from Belgium, Canada, Czech Republic, France, Germany, Italy, Japan, Latvia, The Netherlands, Mexiw, Poland, Portugal, Romania, Russia, Slovenia, Spain, Sweden, Switzerland, Ukraine, the United Kingdom and the USA. The participants all presented excellent oral and poster presentations and discussed their current research. In total, 34 talks were presented, covering the fields of Cultural Heritage (3), Climatology (7),Glaciology (l), Isotopes (5), Geomorphology (4), Ecology (8) and Wood anatomy and Cambial activity (6). Furthermore, 39 posters were displayed to the audience. Two invited speakers gave a talk about the study of tree-ring patterns in wooden cultural heritage. Prof. Dieter Eckstein focussed on dendro-provenancing, where tree-ring studies are used to document and to reconstruct the historical timber trade in Europe. Prof. Partick Hoffsummer gave an overview of his exhaustive work on roofs from historical buildings in Northern France and Belgium, and the evolutional patterns that can be observed in their construction. As an overall conclusion of the conference Prof. Fritz Schweingruber plead for an integration of dendrochronology and wood anatomy to improve ...