The tree mixture, planted in April 2013, represents the typical mixture of a warm lowland forest of lower Austria (Tulln, near Vienna). In experimental plots, the effects of tree biodiversity on growth, water relations, rhizosphere diversity and C sequestration will be investigated.

The B-Tree Austrian Site is a member of the TreeDivNet-Research-Platform.

Basic Design

Acer platanoides, Carpinus betulus, Quercus robur and Tilia cordata were planted in a full factorial design consisting of monoculture plots and plots of 2 or 4 species. The planted 2-species mixtures will allow the comparison of blocks dominated by tree species associated with ectomycorrhizal fungi (Carpinus and Quercus) or arbuscular mycorrhizal fungi (Tilia and Acer). Each monoculture or species mixture is replicated 4 times.
The trees are planted in a hexagonal design with 1 m distance between each tree, which will allow thinning after canopy closure.

Site Characteristics

Location Tulln, Lower Austria
Area 1.2 ha
No of plots 44
No of trees planted 11 000
Planting date April 2013
Former land use grassland with trees
Altitude 200 m
Soil type moist chernozem
Species pool Acer platanoides, Carpinus betulus, Quercus robur, Tilia cordata

Site Maintenance

In 2012, the single trees at the site (Abies alba, Pinus sylvestris) were removed, and in July, the site was ploughed and sown with wheat. In March 2013, the site was ploughed and raked; the trees were planted in April. From May to August, the site was irrigated weekly with ground water (30 mm per month). Weeds and grass have been controlled by hand weeding and mowing. 


During the site preparation, soil samples were taken in a 10 m x 10 m grid to a depth of 30 cm. We looked at variation in soil depth and the soil profile across the site and determined soil pH and the concentrations of total C and N, exchangeable P, extractable Ca, Mg, K. To quantify the heterogeneity of the site, the height of the wheat crop as well as the leaf chlorophyll levels of the wheat were determined. The soil pH lay between 7.0 - 7.8 (CaCl2) or 7.8 - 8.8 (H2O).
Future research will focus on the effects of tree diversity on tree growth, water relations, rhizosphere diversity and C sequestration.  


Douglas Godbold & Boris Rewald & Hans Göransson

Institute of Forest Ecology
Peter Jordanstraße 82
A-1190 Vienna/Austria