Veteran trees in decline: Stratified national monitoring of oaks in Norway

10 S.

e-journal

200211171

Old veteran trees function as biodiversity hotspots in both forests and open landscapes, and protecting such trees is an important measure to halt loss of biodiversity. Nevertheless, the number of veteran trees continues to decline worldwide, although estimates of this decline mainly stem from geographically restricted case studies. In Norway, veteran oak trees have received special protection since 2011 through the Norwegian Biodiversity Act, however, there is a lack of knowledge on status and trends for these trees. A national monitoring program was started in 2012, using a random, stratified sampling procedure. We use the data from the baseline survey and the first monitoring revisit to estimate the total number as well as mortality trends of veteran oaks in Norway. Further, we assess recruitment potential (in the baseline survey) and changes in variables describing ecological
state such as regrowth.
Keywords: Quercus, Ancient tree, Tree inventory, Monitoring, Annual decline, Biodiversity hotspot, Heritage trees