Table 1. Variables in each NFI plot used in analyses.
Variable Explanation
Diameter at breast height (DBH) Average of all trees, basal area-weighted.
Height If height ≥ 7 m, the average height of all trees weighted by basal area; if height < 7 m, the arithmetic average of the dominant trees.
Tree density Number of trees ha–1.
Above-ground biomass density OD t ha–1 of stemwood with bark and living branches including needles and fine fractions (calculated according to Marklund 1988).
Standing volume per ha Stem volume over bark and above the stump, including the tops.
Maturity class Cutting class according to Nilsson et al. (2011).
Stand age Years
Composition of tree species Proportions (%) of Scots pine, lodgepole pine, spruce and broadleaves.
Ground moisture, soil parent material Classes using the Swedish terrain classification method of Berg (1992).
Pre-commercially thinned (PCT) No / Yes
Commercially thinned No / Yes
Previous land use other than forest No / Yes (and use, e.g. pasture, arable land, gravel pit, etc.)
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Fig. 1. The regions of Sweden (Northern Norrland, Southern Norrland, Svealand, Götaland), the areal proportion (%) of productive forest land by county (left), the areal proportion of BDTF within the productive forest land by county (middle) and the average stand age of BDTF by county (right). Results refer to BDTF of category D (i.e. applying all selection constraints to the overall NFI dataset). © Lantmäteriet, i2014/764.

Table 2. The area of BDTF (defined using indicated constraints), the ratio of BDTF area to the total area of productive forest, the BDTF growing stock and the ratio of BDTF growing stock to the total growing stock on Sweden’s productive forest land.
Category BDTF area
(M ha) 		Ratio of BDTF/total productive forest areal (%) BDTF growing stock (M OD t) Ratio of BDTF/total growing stock (%)
A 9.77 43.5 564.07 34.2
B 6.94 30.9 518.25 31.4
C 2.97 13.2 160.81 9.7
D 2.11 9.4 119.26 7.2
Table 3. Regional distribution of BDTF area (ha), average biomass of growing stock (OD t ha–1) and total standing biomass (M OD t), by average stem volume subclass (BDTF of category D).
Region Subclass (average stem volume “x”, dm3)
10 ≤ x < 20 20 ≤ x < 30 30 ≤ x < 40
ha OD t ha–1 M OD t ha OD t ha–1 M OD t ha OD t ha–1 M OD t
1 N.Norrland 262 292 50.1 13.14 147 003 54.6 8.03 108 859 55.3 6.02
2 S.Norrland 195 624 58.8 11.51 128 204 61.0 7.83 79 770 57.3 4.57
3 Svealand 146 521 53.6 7.85 83 711 55.3 4.63 57 296 57.3 3.28
4 Götaland 93 846 54.4 5.10 53 124 59.7 3.17 49 465 63.6 3.15
Total 698 282 53.8 37.60 412 042 57.4 23.65 295 390 57.6 17.02
  40 ≤ x < 60 60 ≤ x < 120 Total
  ha OD t ha–1 M OD t ha OD t ha–1 M OD t ha OD t ha–1 M OD t
1 N.Norrland 137 044 49.3 6.76 142 258 54.8 7.80 797 455 52.3 41.74
2 S.Norrland 76 397 61.1 4.67 97 930 60.3 5.90 577 924 59.7 34.48
3 Svealand 75 715 60.5 4.58 66 881 59.3 3.96 430 125 56.5 24.30
4 Götaland 64 683 67.1 4.34 44 556 66.7 2.97 305 673 61.3 18.73
Total 353 839 57.5 20.34 351 624 58.7 20.64 2 111 177 56.5 119.26
Table 4. Proportions (%) of BDTF dominated by indicated single species or pairs of co-dominants (accounting for at least 60% and at least 80% of stands’ cover, respectively; BDTF of category D).
Dominant tree species in the stand Proportion (%) of total BDTF area
(2.11 M ha) 		Proportion (%) of BDTF area on abandoned farmland (0.04 M ha)
Broadleaves ( ≥ 60%) 10.6 24.6
Spruce (Picea abies) ( ≥ 60%) 26.6 65.8
Scots pine (Pinus sylvestris) ( ≥ 60%) 52.0 5.7
Lodgepole pine (Pinus contorta) ( ≥ 60%) 7.4 -
Spruce and scots pine ( ≥ 80%) 0.8 1.1
Spruce and broadleaves ( ≥ 80%) 1.7 -
Scots pine and broadleaves ( ≥ 80%) 0.7 2.9
Scots pine and lodgepole pine ( ≥ 80%) 0.1 -
Total 100 100
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Fig. 2. Characteristics of the BDTF (of category D) across the whole of Sweden. The Y-axis shows the cumulative percentage of the area occupied by the forests characterized by the parameters represented on the upper and lower X-axes. The absolute BDTF areas are shown in Table 3.

Table 5. Annual technical harvesting potential of delimbed stemwood and whole (undelimbed) trees from BDTF across regions of Sweden, applying selection constraints A-C and A-D. View in new window/tab.