Fig. 1. Damaged plots by browsing during the period 2000–2014.

Table 1. Summary of stand variables included in the analysis with an overview of their predicted effect on browsing damage occurrence. In brackets is the name of the variables used in the models and in square brackets the units when available or a C if the variable is categorical (details and description of the variables are provided in the Supplementary file 1).
Variable Predicted effect
Age (Age) [yr] -
Development class (DevCl) [C] -
Density (Density) [trees ha –1] -
Diameter (Diam) [cm] Not clear
Height (Height) [m] Not clear
Basal area (BA) [m2 ha–1] -
Stand size (StandSize) [C] Not clear
Stand dominant specie (Spp) [C] + mixed, pine
Percentage of spruce (PercSpr) [%] -
Percentage of pine (PercPne) [%] +
Percentage of birch (PercBrch) [%] +
Percentage of conifer (PercOCo) [%] Not clear
Percentage of deciduous (PercODec) [%] +
Shannon index (Shannon) +
Gini coefficient (Gini) +
Structure (Structure) [C] NA
Population on the stand edge (PopOnEdg) [C] + No edge, agriculture, water and high
Stand edge distance (StandEdgeD) [m] Not clear
Crown cover (CC) [%] Not clear
Altitude (Altitude) [m] +
Site index (SI) [C] -
Previous treatment (PrevTr) + No treatment, cutting of seed trees, thinning, tending, selective cutting and regeneration planting
Slope (Slope) [%] -
Slope length (SlopeL) [m] Not clear
Slope orientation (SlopeO) [C: N,S,W,E] Not clear
Slope distance (SoilD) [m] Not clear
Soil type (SoilT) [C] Not clear
Steepness (Steepness) [%] -
Relief (Relief) [C] Not clear
The predicted effect is “+” when the variable increment means an increase in damage occurrence probability; “-” when the variable increment means a decrease in damage occurrence probability; “Not clear” when the trend is not clear; “NA” when the variable trend is not available.

Fig. 2. Mean estimated variable importance in all 50 models and variability associated. The value 100 corresponds to the most important variable, and the rest are presented in relation to this score. Bars relate to the variability of the values. For all models, age had systematically the highest importance score.


Fig. 3. Classification tree model predicting browsing damage occurrence. Square brackets indicate the node number; No or Browsing indicate the fitted class of non-damage plots and damaged plots, respectively. Below each fitted class it appears the probability of that class and the percentage of the total data present in that node. View larger in new window/tab