Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Figure 9.

Figure 10.

Figure 11.

Figure 12.

Figure 13.

Figure 14.

Figure 15.

Figure 16.

Average model residuals for different models for calculating assortment volumes by tree species_
| Tree species | Assortment | Average model residuals, % | |
|---|---|---|---|
| old model | new model | ||
| Scots pine | saw log | 6.74 | −0.01 |
| firewood | −1.33 | −0.82 | |
| Norway spruce | saw log | 7.78 | 2.40 |
| firewood | −3.67 | −2.55 | |
| Birch species | saw log | 11.83 | 1.23 |
| firewood | 2.21 | −0.16 | |
| European aspen | saw log | 0.75 | 0.42 |
| firewood | 22.48 | −2.34 | |
| Black alder | saw log | −17.98 | −7.84 |
| Grey alder | saw log | −33.45 | −2.99 |
Saw log proportion reduction_
| Tree species | Age used in the Estonian model | Malinen et al. 2007 | Estonian model (Figure 3) | ||
|---|---|---|---|---|---|
| MELA-96 | MELA-05 | Bucking simulation | |||
| Pine | 60–100 | 16.04 | 24.25 | 18.17 | 9–28% |
| Spruce | 60–80 | 2.35 | 17.79 | 6.38 | 10–29% |
| Birch | 50–70 | 30.27 | 29.35 | 41.46 | 38–64% |
Site index classes and site index H100 relationship_
| Site index H100, m | Site index class | Site index class in calculations |
|---|---|---|
| < 11.5 | 5A | 6 |
| 11.5…15.5 | 5 | 5 |
| 15.5…19.5 | 4 | 4 |
| 19.5…23.5 | 3 | 3 |
| 23.5…27.5 | 2 | 2 |
| 27.5…31.5 | 1 | 1 |
| > 31.5 | 1A | 0 |
j_fsmu-2023-0013_tab_008
| Relative diameter of a tree in relation to the diameter of a stand element | Number of trees, per mille |
|---|---|
| 0.4 | 11 |
| 0.5 | 34 |
| 0.6 | 59 |
| 0.7 | 96 |
| 0.8 | 131 |
| 0.9 | 154 |
| 1.0 | 154 |
| 1.1 | 132 |
| 1.2 | 96 |
| 1.3 | 64 |
| 1.4 | 35 |
| 1.5 | 18 |
| 1.6 | 10 |
| 1.7 | 4 |
| 1.8 | 2 |
General data on felled elements included in the analysis_ Site index class and site index H100 relationship are described in Table 2_
| Tree species | No. of elements | Age, years | Site index class | ||
|---|---|---|---|---|---|
| minimum | maximum | maximum | minimum | ||
| Scots pine (Pinus sylvestris L.) | 14,013 | 21 | 219 | 1A | 5A |
| Norway spruce (Picea abies (L.) H. Karst.) | 3,045 | 16 | 177 | 1A | 5 |
| Silver and downy birch (Betula pendula Roth, Betula pubescens Ehrh.) | 7,145 | 22 | 153 | 1A | 5 |
| European aspen (Populus tremula L.) | 1,862 | 23 | 140 | 1A | 3 |
| Black alder (Alnus glutinosa (L.) Gaertn.) | 679 | 37 | 138 | 1A | 4 |
| Grey alder (Alnus incana (L.) Moench) | 770 | 18 | 75 | 1A | 4 |
| Total | 27,514 | 16 | 219 | 1A | 5A |
Parameters of timber assortments (roundwood) used in the analysis_
| Tree species | Assortment | Top diameter, cm | Length, m | ||
|---|---|---|---|---|---|
| minimum | step | Maximum | |||
| Scots pine | Log | 28–… | 3.1 | 0.3 | 6.1 |
| Log | 23–28 | 3.1 | 0.3 | 6.1 | |
| Log | 18–23 | 3.1 | 0.3 | 6.1 | |
| Log | 13–18 | 3.1 | 0.3 | 6.1 | |
| Log | 10–13 | 3.1 | 0.3 | 6.1 | |
| Pulpwood | 5 | 3.0 | 3.0 | ||
| Firewood | 3 | 3.0 | 3.0 | ||
| Norway spruce | Log | 25–… | 3.1 | 0.3 | 6.1 |
| Log | 18–25 | 3.1 | 0.3 | 6.1 | |
| Log | 13–18 | 3.1 | 0.3 | 6.1 | |
| Log | 10–13 | 3.1 | 0.3 | 6.1 | |
| Pulpwood | 5 | 3.0 | 3.0 | ||
| Firewood | 3 | 3.0 | 3.0 | ||
| Silver and downy birch | Log | 14–… | 3.1 | 0.3 | 6.1 |
| Pulpwood | 5 | 3.0 | 3.0 | ||
| Firewood | 3 | 3.0 | 3.0 | ||
| European aspen | Log | 14–… | 3.1 | 0.3 | 6.1 |
| Pulpwood | 5 | 3.0 | 3.0 | ||
| Firewood | 3 | 3.0 | 3.0 | ||
| Black alder | Log | 18–… | 3.1 | 0.3 | 6.1 |
| small log | 14–18 | 3.1 | 0.3 | 6.1 | |
| Firewood | 3 | 3.0 | 3.0 | ||
| Grey alder | Log | 18–… | 3.1 | 0.3 | 6.1 |
| small log | 14–18 | 3.1 | 0.3 | 6.1 | |
| Firewood | 3 | 3.0 | 3.0 | ||
Equation parameters obtained by comparing roundwood assortment volumes_
| Tree species | Assortment | a | b | c | d | f | i | R2 | p-value |
|---|---|---|---|---|---|---|---|---|---|
| Scots pine | Log volume reduction | −0.4560 | −6.7947 | −46.8016 | 99 | 100 | 1 | 0.0356 | < 0.0001 |
| Firewood increase | 2.7817 | 1.0015 | 267.0156 | 99 | 100 | 1 | 0.0233 | < 0.0001 | |
| Norway spruce | Log volume reduction | 0.2145 | 6.7871 | −0.0656 | 1 | 20 | 1.1 | 0.0158 | < 0.0001 |
| Firewood increase | −3.1086 | 17.2571 | −91.9444 | 49 | 50 | 0.1 | 0.0195 | < 0.0001 | |
| Silver and downy birch | Log volume reduction | 1.0622 | 9.1595 | 0.3487 | 10 | 50 | 1 | 0.0945 | < 0.0001 |
| Firewood increase | 0.1733 | 3.2363 | 0.0063 | 0,1 | 1 | 1 | 0.0052 | < 0.0001 | |
| Veneer log | −3.6396 | 10.4272 | −2.6481 | 10 | 20 | 0.1 | 0.1445 | < 0.0001 | |
| European aspen | Log volume reduction | 1.0522 | 12.6587 | 15.8415 | 49 | 50 | 1 | 0.1991 | < 0.0001 |
| Firewood increase | −1.0607 | 28.4761 | −0.0969 | 0.1 | 0.2 | 0.1 | 0.0381 | < 0.0001 | |
| Black alder | Log volume reduction | 0.6106 | 22.1975 | −0.0837 | 1 | 2 | 1 | 0.0789 | < 0.0001 |
| Grey alder | Log volume reduction | −6.106 | 12.485 | −61.485 | 90 | 100 | 1 | 0.0353 | 0.0257 |
The parameter n of the volume change Equation 3 and the parameters of the Equation for calculating its coefficients a, b and c (Equation 5)_
| Tree species | Formula | Constant | Equation coefficients | |||
|---|---|---|---|---|---|---|
| k | l | m | n | |||
| Scots pine | log volume reduction | a | −2.259 | 0.24693 | −0.01345 | 3 |
| b | 11.35752 | −2.10076 | 0.1712 | |||
| c | 894.235 | −304.766 | 28.869 | |||
| firewood increase | a | −3.3503 | 0.0159 | −0.0013 | 2 | |
| b | 1.5375 | −0.0271 | 0.0022 | |||
| c | 1.5328 | −0.0261 | 0.0021 | |||
| Norway spruce | log volume reduction | a | −0.89371 | −0.13886 | 0.01049 | 4 |
| b | 29.4603 | 4.36432 | −0.33114 | |||
| c | −366800 | −228124 | −4093 | |||
| firewood increase | a | −1.66542 | −0.06081 | 0.0012 | 4 | |
| b | 29.59224 | 0.27817 | 0.09189 | |||
| c | −115756 | −24063 | 89.533 | |||
| Silver and downy birch | log volume reduction | a | −0.39607 | 0.06595 | −0.0032 | 5 |
| b | 28.784 | −1.088 | 0.042 | |||
| c | 3829316 | 885112 | 80082 | |||
| firewood increase | a | −1.67591 | 0.01012 | −0.00097 | 4 | |
| b | 25.21899 | −0.21777 | 0.02076 | |||
| c | −211985 | 7782.9 | −749.88 | |||
| veneer block recovery | a | −2.7282 | −0.2457 | −0.0683 | 4 | |
| b | 30.281 | 12.921 | −1.639 | |||
| ln(-c) | 12.655 | 0.8226 | 0.2254 | |||
| European aspen | log volume reduction | a | 0.09015 | 0.01429 | −0.00061 | 4 |
| b | 27.49482 | −0.06593 | −0.01049 | |||
| c | −150369 | 7285 | −387 | |||
| firewood increase | a | −1.34789 | −0.01386 | 0.0011 | 5 | |
| b | 46.31225 | 0.04688 | −0.00447 | |||
| c | 10507971 | 920148 | −82200 | |||
| Black alder | firewood increase | a | 0.1209 | −0.09111 | 0.01198 | 10 |
| b | 73.66109 | −4.70172 | 0.78866 | |||
| c | −2.703·1015 | −5.258·1015 | 6.974·1014 | |||
| Grey alder | firewood increase | a | −0.82187 | −0.30129 | 0.00434 | 7 |
| b | 58.03680 | −0.13325 | 5.87003 | |||
| c | 3.048·1011 | −2.887·1011 | 4.242·1012 | |||