Figure 1.
Location of the study area: 1 – Teterivske FE, 2 – Dniprovsko-Teterivske SFHE, 3 – Vyschedubechanske FE. Damage degree: low, up to 30% of shoots are damaged; moderate, 30–50% of shoots are damaged; high, <51% of shoots are damaged
Table 1.
Detailed information about variables according to the damage inventory data from ungulate browsing at three experimental enterprises. The number of measurements (n) represents the total number of surveyed plots. Indicators are presented in the respective mean (±SD) for the three experimental enterprises for each variable
| Variables | Vyschedubechanske FE | Teterivske FE | Dniprovsko-Teterivske SFHE |
|---|---|---|---|
| 26,746.00, ha | 32,169.00, ha | 18,477.00, ha | |
| Young forest area (up to 10 years old), ha | 914.00 | 1,390.00 | 210.00 |
| Percentage of young forest area, % | 3.42 | 4.32 | 1.13 |
| Number of measurements (n) | 144 | 41 | 90 |
| Area of young forests damaged by ungulates, ha | 0.25 (±0.27) | 0.50 (±0.46) | 0.33 (±0.31) |
| Average age of trees, years | 3.38 (±1.01) | 2.85 (±1.01) | 3.02 (±1.37) |
| Proportion of areas with damages by ungulates to the total area of young forest | 0.027 (±0.03) | 0.036 (±0.03) | 0.159 (±0.15) |
| Proportion of areas with damage of the main species to the areas with damages | 0.25 (±0.05) | 0.49 (±0.12) | 0.27 (±0.07) |
| Average damage degree, score | 1.91 (±0.47) | 2.37 (±0.77) | 1.94 (±0.71) |
| Proportion of areas with low damage | 0.026 (±0.018) | 0.022 (±0.019) | 0.145 (±0.129) |
| Proportion of areas with moderate damage | 0.026 (±0.032) | 0.027 (±0.022) | 0.189 (±0.175) |
| Proportion of areas with high damage | 0.041 (±0.028) | 0.045 (±0.039) | 0.110 (±0.071) |
| Moose density index | 0.004 | 0.005 | 0.005 |
| Red deer density index | 0.009 | 0.007 | 0.015 |
| Roe deer density index | 0.018 | 0.021 | 0.017 |
| Proportion of Scots pine area | 0.71 (±0.01) | 0.83 (±0.02) | 0.68 (±0.02) |
| Proportion of silver birch | – | 0.11 (±0.02) | 0.15 (±0.02) |
| Proportion of English oak | 0.04 (±0.01) | 0.04 (±0.01) | 0.17 (±0.02) |
| Proportion of red oak | 0.23 (±0.02) | – | – |
Figure 2.
Photo of the damage degree in Scots pine plants: A – low, up to 30% of shoots browsed; B – moderate, 30–50% of shoots browsed; C – high, 51% or more of shoots browsed
Figure 3.
Scaled variable importance plot from a RFM selection process to achieve the smallest out-of-bag error for Vyschedubechanske FE, Dniprovsko-Teterivske SFHE and Teterivske FE. Panels represent the importance of variables: moose, deer, red_deer – ungulates density index; prop_area_Pine, Oak and R_Oak – the proportion of the young forest area of Scots pine, English oak and red oak. Higher values indicate increased variable importance
Table 2.
Significance of features according to the results of the generalized linear model. Values represent model coefficients indicating the effect size and direction of each variable on the predicted degree of browsing damage
| Features | Vyschedubechanske FE, n = 144 | Teterivske FE, n = 41 | Dniprovsko-Teterivske SFHE, n = 90 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| SE | z-value | p-value | SE | z-value | p-value | SE | z-value | p-value | |
| Intercept | –1.72 (±1.16) | –1.49 | 0.14 | –4.66 (±21.84) | –0.214 | 0.83 | –2.01 (±1.50) | –1.334 | 0.18 |
| Moose density | 957.66 (±5276.23) | 0.182 | 0.18 | 135.28 (±989.14) | 0.137 | 0.90 | –301.88 (±817.16) | –0.369 | 0.71 |
| Deer density | –555.56 (±3820.72) | –0.145 | 0.88 | 17.52 (±1982.96) | –0.009 | 0.99 | –13.39 (±58.41) | –0.229 | 0.82 |
| Roe deer density | –49.84 (±442.62) | –0.113 | 0.91 | –69.27 (±1455.44) | –0.048 | 0.96 | 179.92 (±465.09) | 0.387 | 0.70 |
| Age of plants | 0.03 (±0.27) | 0.127 | 0.90 | 0.01 (±0.95) | 0.018 | 0.99 | –0.10 (±0.27) | –0.376 | 0.71 |
| Proportion of Scots pine, % | –1.03 (±0.86) | –1.202 | 0.23 | 1.23 (±13.45) | 0.091 | 0.92 | –0.005 (±1.14) | –0.004 | 0.99 |
| Proportion of silver birch, % | – | – | – | 1.04 (±13.66) | 0.077 | 0.94 | – | – | – |
| Proportion of English oak, % | –0.80 (±1.50) | –0.537 | 0.59 | 1.22 (±13.77) | 0.089 | 0.92 | –0.23 (±0.99) | –0.239 | 0.81 |
| Proportion of red oak, % | –0.87 (±0.75) | –1.152 | 0.25 | – | – | – | – | – | – |
| Forest type | –0.03 (±0.50) | –0.063 | 0.95 | –0.01 (±0.72) | 0.016 | 0.99 | 0.06 (±0.25) | 0.224 | 0.82 |
| Damage degree, score | 0.005 (±0.55) | 0.010 | 0.99 | –0.06 (±0.67) | –0.090 | 0.93 | –0.05 (±0.37) | –0.148 | 0.88 |
| Pearson chi2 | 0.347 | 0.125 | 0.98 | ||||||
| Pseudo R-squ. | 0.028 | 0.040 | 0.121 | ||||||