Mid-term economical consequences of roadside tree topping

Abstract

Tree care in Wallonia (Belgium) depends on the institution in charge (regional or local). Most municipalities have no statutory guidelines for the maintenance of their tree stock. In this situation, it is not surprising that trees are still topped. Moreover, tree owners think that topping is a fast and cheap way to prune trees. We studied crown restoration of 281 roadside Tilia x europaea L. individuals that were topped during the winter of 1992–1993. Our goal was the economic evaluation of three pruning scenarios. Time needed to prune and related tree parameters (such as tree growth) were measured to calculate pruning costs and trees value evolution between 1992 and 2022. Scenario 1 included topping and the necessary crown restoration. Because of differences in topping intensity between the individuals, we were able to categorise the trees into four groups with particular restoration planning. Scenario 2 considered regular topping and scenario 3 regular thinning. We confirmed that topping is not cheaper than regular crown thinning. In the medium term (30 years), topping is 1.4 fold more costly than selective thinning. Also, mean tree value was reduced by about 10 after regular topping.