Abstract

We investigated the spatial distribution of browsing and damage by moose (Alces alces) in young Scots pine (Pious sylvestris) stands of central Sweden. The study involved four spatial scales from landscape to individual trees and aimed at evaluating the possibilities of using selective thinning of damaged pine stands as a tool for reducing the economic losses for forestry. As expected, we found that damage on pine main stems is unevenly distributed between young pine forest stands in the landscape, but without any spatial autocorrelation at this scale. On stand scale however, there was a positive spatial autocorrelation of survey plots including pine trees damaged by moose. This relationship was strongest at short distances and ceased at around 350 m between plots. Both percent recent and previous damage on pine main stems were negatively correlated with the number of pine stems per plot, suggesting that keeping a higher pine stem density may reduce the damage levels. However, an increasing density of birch instead increased the probability of recent damage to the pines. The most important explanatory variable for recent damage on pine main stems on plot level was previous damage on the same. Therefore damaged pines that are spared during pre-commercial thinning may continue to be eaten by moose and possibly lighten the browsing pressure on previously undamaged trees. We also found that both recent damage and browsing on a particular pine enhances the risk of recent damage and browsing, respectively, also on the nearest neighboring pine. Removing damaged trees while thinning may therefore create undesired gaps within the stands. On tree level browsing of lateral shoots increased the chances of stem damages on individual trees and vice versa, suggesting that individual trees may simultaneously be affected by moose foraging in more than one way, i.e. damage may cause permanent change in stem structure, while browsing of lateral shoots may retard stem growth. In conclusion, we argue that there are means of reducing damage levels in pine stands while performing pre-commercial and commercial thinning, but that the actions have to be evaluated in relation to additional factors on the relevant spatial scale. (C) 2013 Elsevier B.V. All rights reserved.

Keywords

Alces alces; Browsing; Damage; Moose; Pine; Spatial

Published in

Forest Ecology and Management
2013, Volume: 305, pages: 229-238
Publisher: ELSEVIER SCIENCE BV

UKÄ Subject classification

Forest Science
Ecology


Publication identifier

DOI: https://doi.org/10.1016/j.foreco.2013.05.057

Permanent link to this page (URI)

https://res.slu.se/id/publ/89219