Table 1.
Trees composition, age, stand crop woody volume, volume annual wood productivity, stand crop biomass, and annual increase of biomass (data provided by “Marin Drăcea” National Institute for Research and Development in Forestry (INCDS) – planning studies between 1999 and 2017)
| No. | Type of forest | Tree composition | Average age (years) | Volume/ha (m3/ha) | Productivity (m3/ha/year) | Biomass (t/ha) | Increase of biomass (t/ha/year) |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Natural pure forests | |||||||
| 1 | Spruce forest | 10Mo | 100 ± 15 | 208.75 | 11.08 | 90.13 | 4.78 |
| 2 | Spruce forest | 10Mo | 95 ± 25 | 555.09 | 30.18 | 239.96 | 13.05 |
| 3 | Spruce forest | 10Mo | 25 ± 5 | 92.48 | 10.37 | 42.17 | 4.73 |
| 4 | Spruce forest | 10Mo | 100 ± 15 | 463.26 | 14.95 | 196.07 | 6.33 |
| 5 | Pine forest | 10Pi | 85 ± 25 | 256.31 | 14.56 | 119.18 | 6.77 |
| 6 | Beech forest | 10Fg | 130 ± 25 | 171.30 | 13.89 | 129.63 | 10.51 |
| 7 | Beech forest | 10Fg | 105 ± 5 | 170.94 | 14.96 | 130.13 | 11.39 |
| 8 | Beech forest | 10Fg | 75 ± 35 | 179.98 | 19.04 | 139.31 | 14.74 |
| 9 | Beech forest | 10Fg | 150 ± 15 | 121.00 | 5.28 | 88.40 | 3.86 |
| 10 | Beech forest | 10Fg | 105 ± 25 | 215.02 | 11.04 | 158.24 | 8.12 |
| 11 | Beech forest | 10Fg | 140 ± 15 | 276.03 | 9.03 | 199.54 | 6.53 |
| 12 | Beech forest | 10Fg | 100 ± 25 | 201.91 | 10.31 | 148.55 | 7.59 |
| 13 | Beech forest | 10Fg | 150 ± 5 | 402.04 | 14.80 | 283.93 | 10.45 |
| 14 | Beech forest | 10Fg | 150 ± 15 | 389.72 | 15.89 | 249.76 | 10.18 |
| 15 | Beech forest | 10Fg | 130 ± 20 | 342.97 | 13.83 | 355.00 | 14.32 |
| 16 | Beech forest | 10Fg | 170 ± 5 | 495.98 | 11.16 | 102.00 | 2.30 |
| 17 | Beech forest | 10Fg | 180 ± 5 | 139.98 | 5.74 | 291.79 | 11.97 |
| 18 | Turkey oak forest | 10Ce | 50 ± 15 | 148.54 | 5.73 | 121.87 | 4.70 |
| 19 | Turkey oak forest | 10Ce | 50 ± 15 | 144.08 | 6.21 | 118.73 | 5.12 |
| 20 | Turkey oak forest | 10Ce | 55 ± 15 | 114.63 | 4.19 | 93.87 | 3.43 |
| 21 | Turkey oak forest | 10Ce | 60 ± 15 | 140.08 | 3.99 | 113.82 | 3.24 |
| 22 | Turkey oak forest | 10Ce | 80 ± 15 | 147.68 | 3.88 | 119.73 | 3.15 |
| 23 | Sessile oak forest | 10Go | 110 ± 15 | 196.82 | 15.87 | 291.79 | 23.53 |
| 24 | Oak forest | 10St | 45 ± 15 | 209.44 | 8.21 | 154.53 | 6.06 |
| 25 | Oak forest | 10St | 55 ± 15 | 209.99 | 8.36 | 155.03 | 6.17 |
| Natural mixed forests | |||||||
| 26 | Fir forest | 7Br, 2Fg, 1Mo | 130 ± 30 | 443.90 | 20.96 | 217.55 | 10.27 |
| 27 | Fir forest | 7Br, 2Fg, 1Mo | 110 ± 40 | 550.32 | 15.92 | 265.00 | 7.67 |
| 28 | Fir forest | 4Br, 3Fg, 3Mo | 120 ± 30 | 396.03 | 18.63 | 206.09 | 9.69 |
| 28 | Fir forest | 6Br, 2Fg, 2Mo | 110 ± 25 | 519.04 | 20.02 | 252.28 | 9.73 |
| 30 | Fir forest | 8Br, 2Fg | 110 ± 25 | 168.98 | 10.42 | 83.96 | 5.18 |
| 31 | Fir forest | 6Br, 1Fg, 3Mo | 130 ± 15 | 486.29 | 16.13 | 220.56 | 7.32 |
| 32 | Fir forest | 5Br, 3Fg, 2Mo | 170 ± 10 | 412.98 | 14.98 | 212.70 | 7.72 |
| 33 | Fir forest | 6Br, 4Fg | 130 ± 25 | 439.98 | 17.57 | 240.67 | 9.61 |
| 34 | Fir forest | 6Br, 2Fg, 2Mo | 140 ± 15 | 316.03 | 10.49 | 152.81 | 5.07 |
| 35 | Fir forest | 6Br, 2Fg, 2Mo | 130 ± 15 | 327.85 | 11.60 | 158.86 | 5.62 |
| 36 | Fir forest | 6Br, 4Fg | 160 ± 10 | 157.89 | 9.76 | 88.18 | 5.45 |
| 37 | Fir forest | 6Br, 4Fg | 170 ± 10 | 62.98 | 10.18 | 38.48 | 6.22 |
| 38 | Fir forest | 6Br, 2Fg, 2Mo | 140 ± 15 | 101.04 | 10.63 | 52.26 | 5.50 |
| 39 | Fir forest | 6Br, 2Fg, 2Mo | 140 ± 15 | 276.04 | 12.59 | 135.08 | 6.16 |
| 40 | Fir forest | 8Br, 2An | 150 ± 15 | 243.31 | 7.87 | 82.41 | 2.67 |
| 41 | Fir forest | 5Br, 2Fg, 3Mo | 130 ± 20 | 224.90 | 10.37 | 110.11 | 5.08 |
| 42 | Alpine mixed forest | 4Br, 4Fg, 2Mo | 150 ± 10 | 258.03 | 11.88 | 141.97 | 6.54 |
| 43 | Alpine mixed forest | 4Br, 4Fg, 2Mo | 150 ± 10 | 497.03 | 16.17 | 269.94 | 8.78 |
| 44 | Alpine mixed forest | 5Br, 5Fg, | 150 ± 10 | 306.06 | 10.95 | 175.94 | 6.29 |
| 45 | Beech forest | 6Fg, 3Br, 1Mo | 120 ± 15 | 86.40 | 10.08 | 56.34 | 6.57 |
| 46 | Beech forest | 6Fg, 4Br, | 170 ± 10 | 265.02 | 12.32 | 161.97 | 7.53 |
| 47 | Beech forest | 5Fg, 3Br, 2Mo | 110 ± 30 | 509.02 | 33.03 | 300.84 | 19.52 |
| 48 | Beech forest | 5Fg, 3Br, 2Mo | 110 ± 30 | 480.03 | 36.72 | 286.80 | 21.94 |
| 49 | Beech forest | 7Fg, 2Br, 1Mo | 150 ± 10 | 407.04 | 17.18 | 260.05 | 10.98 |
| 50 | Spruce forest | 5Mo, 3Br, 2Fg | 120 ± 15 | 208.75 | 11.08 | 102.88 | 5.46 |
| 51 | Spruce forest | 5Mo, 3Br, 2Fg | 120 ± 15 | 421.04 | 12.50 | 202.90 | 6.02 |
| 52 | Spruce forest | 5Mo, 3Br, 2Fg | 140 ± 15 | 523.02 | 15.54 | 252.05 | 7.49 |
| 53 | Spruce forest | 5Mo, 3Br, 2Fg | 150 ± 10 | 411.02 | 13.46 | 198.66 | 6.51 |
| 54 | Spruce forest | 6Mo, 2Br, 2Fg | 90 ± 10 | 414.26 | 8.64 | 197.92 | 4.13 |
| 55 | Spruce forest | 9Mo, 1Fg | 120 ± 5 | 475.04 | 6.42 | 211.36 | 2.86 |
| 56 | Spruce forest | 5Mo, 3Br, 2Fg | 130 ± 10 | 537.18 | 4.79 | 215.70 | 1.92 |
| 57 | Turkey oak forest | 7Ce, 2Gi, 1Fr | 45 ± 20 | 30.97 | 4.38 | 28.67 | 4.05 |
| 58 | Turkey oak forest | 6Ce, 4Gi | 30 ± 25 | 129.18 | 4.98 | 114.04 | 4.40 |
| 59 | Turkey oak forest | 6Ce, 3St, 1Ca | 120 ± 5 | 247.35 | 2.87 | 189.42 | 2.20 |
| 60 | Turkey oak forest | 6Ce, 3St, 1Gi | 65 ± 15 | 221.77 | 5.72 | 177.67 | 4.58 |
| 61 | Oak forest | 7St, 3Fr | 60 ± 15 | 91.96 | 6.71 | 69.76 | 5.09 |
| 62 | Oak forest | 6St, 4Ce | 50 ± 15 | 124.12 | 7.62 | 97.75 | 6.00 |
| 63 | Oak forest | 6St, 4Fr | 45 ± 20 | 166.09 | 7.49 | 122.55 | 5.53 |
| 64 | Willow forest | 6Sa, 4Fr | 20 ± 15 | 72.49 | 9.36 | 47.96 | 6.19 |
| 66 | Poplar forest | 7Pl, 3Fr | 35 ± 10 | 294.02 | 8.19 | 169.24 | 4.71 |
| 66 | Ash forest | 8Fr, 2Pl | 30 ± 10 | 144.85 | 7.69 | 100.68 | 5.34 |
| Planted forests | |||||||
| 67 | Acacia planted forest | 10Sc | 5 | 10.48 | 5.62 | 9.82 | 5.27 |
| 68 | Acacia planted forest | 10Sc | 5 | 7.96 | 7.01 | 9.13 | 8.04 |
| 69 | Acacia planted forest | 10Sc | 10 | 32.02 | 5.81 | 23.08 | 4.19 |
| 70 | Acacia planted forest | 10Sc | 5 | 17.02 | 6.39 | 14.28 | 5.36 |
| 71 | Acacia planted forest | 10Sc | 7 | 19.01 | 8.20 | 16.60 | 7.16 |
| 72 | Acacia planted forest | 10Sc | 30 | 66.03 | 1.98 | 41.49 | 1.24 |
| 73 | Poplar planted forest | 10Pl | 35 | 326.16 | 6.97 | 159.82 | 3.49 |
| 74 | Poplar planted forest | 10Pl | 30 | 300.28 | 11.99 | 147.14 | 6.11 |
| 75 | Poplar planted forest | 10Pl | 15 | 99.34 | 14.22 | 48.68 | 7.97 |
| 76 | Poplar planted forest | 10Pl | 35 | 407.19 | 11.22 | 199.52 | 5.65 |
| 77 | Poplar planted forest | 10Pl | 25 | 76.35 | 15.26 | 37.41 | 8.97 |
| 78 | Poplar planted forest | 10Pl | 25 | 138.12 | 6.42 | 67.68 | 3.29 |
| 79 | Poplar planted forest | 10Pl | 10 | 78.15 | 16.04 | 38.29 | 71.41 |
| 80 | Poplar planted forest | 10Pl | 10 | 13.31 | 5.9 | 6.52 | 2.89 |
| 81 | Poplar planted forest | 10Pl | 5 | 5.49 | 6.32 | 2.69 | 3.10 |
| 82 | Ash planted forest | 10Fr | 90 | 269.02 | 2.97 | 190.39 | 2.10 |
| 83 | Willow planted forest | 10Sa | 15 | 148.69 | 18.31 | 85.17 | 10.49 |
| 84 | Willow planted forest | 10Sa | 5 | 7.29 | 3.98 | 3.72 | 2.03 |
| 85 | Spruce planted forest | 10Mo | 50 | 278.35 | 11.38 | 118.79 | 4.86 |
| 86 | Spruce planted forest | 10Mo | 30 | 174.97 | 9.85 | 75.78 | 4.27 |
| 87 | Spruce planted forest | 10Mo | 25 | 109.23 | 10.36 | 49.03 | 4.65 |
| 88 | Mixed planted, poplar and ash forest | 5Pla, 5Fr | 40 | 217.09 | 5.93 | 112.63 | 3.08 |
| 89 | Mixed planted, willow and poplar forest | 7Pln, 3Sa | 20 | 191.17 | 13.76 | 95.29 | 6.86 |
| 90 | Mixed planted, willow and poplar forest | 7Pln, 3Sa | 15 | 135.26 | 13.61 | 66.54 | 6.70 |
[i] Legend: 1 = 10%, 2 = 20%, 3 = 30%, 4 = 40%, 5 = 50%, 6 = 60%, 7 = 70%, 8 = 80%, 9 = 90%, 10 = 100%; Mo = Spruce, Pi = Pine, Ce = Turkey oak, Fg = Beech, Go = Sessile oak, St = Oak, Br = Fir, Sa = Willow, Pl = Poplar, Gi = Hungarian oak, Fr = Ash, Sc = Acacia, Pln = Bleak Poplar, Pla = White Poplar, An = Alder, Ca = Hornbeam (Ex: 10 Mo = 100% Spruce; 7Br, 2Fg, 1Mo = 70% Fir, 20% Beech, 10% Spruce)
Table 2.
Tree wood density and wood caloric capacity at 0%, 15%, 30% humidity (data were obtained in the INCDS laboratories)
| No. | Species | Wood density (kg/m3) | Caloric capacity (Kcal/kg) 0% humidity | Caloric capacity (Kcal/kg) 15% humidity | Caloric capacity (Kcal/kg) 30% humidity | Caloric capacity (KWh/kg) 0% humidity | Caloric capacity (KWh/kg) 15% humidity | Caloric capacity (KWh/kg) 30% humidity |
|---|---|---|---|---|---|---|---|---|
| 1 | Acacia Robinia pseudoacacia | 610 | 4527 | 3575 | 3347 | 5.264 | 4.157 | 4.003 |
| 2 | Alder Alnus glutinosa | 530 | 4316 | 3392 | 3192 | 5.019 | 3.948 | 3.697 |
| 3 | Ash Fraxinus excelsior | 700 | 4255 | 3340 | 3201 | 4.948 | 3.884 | 3.529 |
| 4 | Beech Fagus sylvatica | 700 | 4494 | 3545 | 3000 | 5.226 | 4.122 | 3.488 |
| 5 | Bleak Poplar Populus nigra | 420 | 4123 | 3230 | 3128 | 4.786 | 3.780 | 3.489 |
| 6 | Fir Abies alba | 410 | 4654 | 3690 | 3520 | 5.412 | 4.291 | 3.997 |
| 7 | Hornbeam Carpinus betulus | 700 | 4062 | 3180 | 3014 | 4.723 | 3.698 | 3.416 |
| 8 | Hungarian oak Quercus frainetto | 940 | 4387 | 3452 | 3243 | 5.109 | 4.018 | 3.772 |
| 9 | Oak Quercus robur | 710 | 4390 | 3450 | 3240 | 5.105 | 4.012 | 3.767 |
| 10 | Pine Pinus sylvestris | 440 | 5066 | 4050 | 3660 | 5.891 | 4.709 | 4.256 |
| 11 | Hybrid Poplar Populus sp. hybrid | 490 | 4223 | 3231 | 3150 | 4.894 | 3.791 | 3.434 |
| 12 | Sessile oak Quercuspetraea | 710 | 4397 | 3439 | 3241 | 5.044 | 4.003 | 3.105 |
| 13 | Spruce Picea abies | 410 | 4696 | 3725 | 3400 | 5.460 | 4.331 | 3.953 |
| 14 | Turkey oak Quercus cerris | 790 | 4395 | 3448 | 3242 | 5.105 | 4.012 | 3.767 |
| 15 | White Poplar Populus alba | 500 | 4120 | 3225 | 3114 | 4.792 | 3.785 | 3.489 |
| 16 | Willow Salix sp. | 510 | 4264 | 3260 | 3112 | 4.958 | 3.756 | 3.559 |

Figure 1.
Species wood caloric capacity at 0%, 15%, 30% humidity

Figure 2.
Biomass, annual increase of biomass, energy, and annual energy production of the pure natural forests

Figure 3.
Biomass, annual increase of biomass, energy, and annual energy production of the mixed natural forests

Figure 4.
Biomass, annual increase of biomass, energy, and annual energy production of the planted forest

Figure 5.
Wood biomass, increase of wood biomass, carbon stock, and annual carbon stock in all the 90 types of forests