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Fig. 1. The locations of the 27 unmanaged Lumes-sites and 206 managed Biosoil-sites that were used for this study. Note that there is some overlap with some of the unmanaged sites.

Table 1. The main characteristics of the standing stock of all the trees in the study sites, with the exception of Dominant species and age that are based on maximum relative basal area. Note that sites PA6C and PA122 are missing from this table as they were not included in the Akujärvi el al. (2025) data.
Site Height (m) DBH (cm) Dominant age (years) Basal area m2 Volume m3 Dominant species Crown cover
JO101 22.6 26.3 175 40 436 Picea abies 57%
JO124 22.7 25.8 173 41 440 Picea abies 51%
JO135 24.8 27.8 183 34 390 Picea abies 46%
JO144 24.3 22.4 123 41 415 Picea abies 65%
PA121 24.6 29.6 167 33 404 Picea abies 31%
PA131 22.9 33.2 159 26 297 Pinus sylvestris 32%
PA132 22.9 27.4 165 31 342 Picea abies 42%
PA6 24.6 26.9 161 40 412 Picea abies 46%
PA61 25.2 31.4 127 65 827 Pinus sylvestris 56%
PA62 24.6 30.7 124 55 688 Pinus sylvestris 50%
PA63 23.5 31.9 110 58 696 Pinus sylvestris 55%
PA67 22.8 24.9 189 28 326 Picea abies 40%
PA7 24.3 28.3 161 41 446 Picea abies 57%
PA8 25.1 30.6 156 35 323 Picea abies 46%
VA101 32.0 34.7 184 27 426 Picea abies 28%
VA109 24.1 26.7 155 45 544 Picea abies 49%
VA112 22.5 18.8 168 34 358 Picea abies 57%
VA207 25.3 19.7 153 20 244 Picea abies 32%
VA209 27.6 26.8 154 38 433 Picea abies 48%
VA210 28.6 31.3 171 37 493 Pinus sylvestris 45%
VA211 27.5 24.8 133 24 332 Picea abies 31%
VA222 29.2 29.1 159 36 505 Picea abies 37%
VA228 22.9 20.5 95 30 335 Picea abies 48%
VA401 26.7 31.1 200 45 513 Picea abies 51%
VA403 27.6 33.4 228 44 570 Picea abies 44%
Table 2. The main characteristics of the managed stands of Biosoil at similar sites by main tree species and age classes.
Age class Average basal area (m2) Average height (m) Number of sites
Pine Spruce Decid. All Pine Spruce Decid. All Pine Spruce Decid. Sum all
0–19 7 1 2 3 4.8 2.7 n/a 4.3 8 9 17 34
20–39 23 20 19 21 11.9 13.1 18.8 12.8 10 11 5 26
40–59 21 24 22 23 17.3 18.3 18.7 17.9 16 19 10 45
60–79 28 28 24 28 23.3 22.3 22.4 22.5 5 31 3 39
80–99 26 27 36 27 21.8 23.7 n/a 23.3 7 23 1 31
100–119 24 27 18 25 21.5 23.9 n/a 23.3 6 13 1 20
120–140 13 27 n/a 26 13.4 24.4 n/a 23.2 1 8 0 9
All 21 24 13 21 16.5 20.9 19.4 19.5 53 114 37 204
Table 3. The mean concentrations of soil carbon and nitrogen for samples from the different soil layers in the unmanaged Lumes-sites with their corresponding standard deviations and the number of samples. Note that this analysis only includes soil particles smaller than 2 mm.
Layer Carbon Nitrogen
g kg–1 Std. deviation n g kg–1 Std. deviation n
Organic layer 408.43 78.57 431 13.46 2.96 431
Mineral soil 0–10 cm 36.76 28.74 432 1.44 0.90 384
Mineral soil 10–20 cm 18.40 11.73 211 0.83 0.51 187
Table 4. The mean, minimum and maximum values of carbon and nitrogen (kg m–2) of different layers for the soil samples measured from the unmanaged Lumes-sites, along with the values from similar sites from the managed Biosoil-data.
Organic layer Mineral layer 0–10 cm Mineral layer 10–20 cm
Mean Min Max Mean Min Max Mean Min Max
Carbon Biosoil 2.058 0.210 7.956 1.777 0.114 5.247 1.141 0.092 5.552
Lumes 2.581 1.071 7.955 2.442 1.684 3.353 1.621 0.863 2.528
Nitrogen Biosoil 0.081 0.008 0.329 0.091 0.005 0.350 0.064 0.005 0.320
Lumes 0.087 0.038 0.364 0.097 0.067 0.180 0.074 0.030 0.128
Table 5. The results of t-tests of the mean values (kg m–2) of the three layers between the managed Biosoil-dataset and the new unmanaged Lumes results.
Layer Carbon Nitrogen
t df p-value t df p-value
Org layers –1.504 31.013 0.143 –0.560 28.990 0.580
0–10 mineral layers –9.071 58.181 <0.001 –4.647 48.87 <0.001
10–20 mineral layers –6.332 41.07 <0.001 –3.886 32.811 <0.001
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Fig. 2. (a) The mass of carbon (kg ha–1) in the organic layer and the top 10 cm of the mineral soil and (b) the mass of nitrogen (kg ha–1) in the organic layer and the top 10 cm of the mineral soil. The “Old” refers to year 2001, 2002 or 2003. Note that three sites are excluded from the figure 2 (b).