The Urban Tree Arboretum in Hørsholm, Denmark: a new tool towards an improved education of arborists and tree managers.

The establishment and management of urban trees require expert knowledge and experience. The Urban Tree Arboretum (UTA) was established in Horsholm, Denmark, to improve basic and advanced education for students and professionals working with tree establishment and management. The UTA presents 120 tree species and cultivars suitable for urban plantings. The trees were established in 2001 in replicates of three or six. Different pruning treatments allow for a comparison of their effect on the trees: formative pruning, shape pruning (topiary), pollarding and non-pruned. Tree dimensions are measured yearly and made available on the website www.bytraearboretet.dk. The website also offers photographic documentation of the trees and their tree features as well as a reference list open for entries by the public. The UTA is integrated part of several courses at the University of Copenhagen and has in 2007 and 2008 been visited by 570 external visitors on 27 guided tours.