Tree of Heaven - "Ailanthus altissima"

The so-called Tree of Heaven (in Latin 'Ailanthus altissima'; in German 'G├Âtterbaum') is a wood species, which originally comes from China and the south of Korea and has been initiated to Europe about 1740. The genus of Trees of Heaven contains about 10 different species, is part of the family of the Bitter Ashes (Simaroubaceaen)and can be classified as an invasive, neophyte species of pioneer-wood. Because of that the Tree of Heaven has a high resistance against salt, dryness, insects and contaminants (no funguses) and a modesty in regard to sunlight and the nutrient content of the ground.

From the forestry and timber-economical point of view, it is interesting that the Tree of Heaven has an enormous growth-performance of about 1.5 m/year and a dynamic circulation by semen (they are able to fly) and coppicing respectively.

The Tree of Heaven has a straight-stemmed growth and reaches dimensions of 20 to 25 m height and diameters of 1.0 to 1.5 m with the age of 20 to 25 years (max. 60). The wood itself is circle-porous and marked by broad, distinct wood rays Furthermore, the Tree of Heaven is similar to our domestic, common Ash Tree (in German 'Esche', in Latin 'Fraxinus excelsior') in reference to the mechanical characteristics, workability and appearance.

Despite of these very positive characteristics, the forest-industries in Europe and North America are endeavored to find ways to revise this wood-species from forest stands, which have already been infiltrated. Austria has also been being infiltrated by this wood-species for three centuries, but forestry and wood-economic aspects for the clarification of the tree of heaven have not been considered and researched yet. Because of that banishment and cleansing of the infiltrated forest stands have not been possible yet.

The 'holz.bau forschungs gmbh', the Institute for Timber Engineering and Wood Technology (TU Graz), the 'Esterhazy Betriebe Gmbh'/Eisenstadt (forest owner), the wood industry 'Rutan Gmbh'/F├╝rstenfeld (industrial partner) and the 'Holzcluster Steiermark Gmbh'/Graz are endeavored to analyze the physical and mechanical characteristics of this wood species (under consideration of the forestry aspects) for the optical and constructive assignment. So it is possible to build up a base for economic uses in Austria and its neighbor countries. In this course the FFG-research-project 'Tree of Heaven - Ailanthus altissima', which runs from the 1st of October 2007 to the 30th of September 2008, has been started. Our disposition is the integration and the execution of educational work for the understanding and the opening of our minds for an useful assignment of a, from now on domestic, new wood-species.