Table 1. Basic characteristics of the study plots. Soil samples were taken from the plots for element analysis and weathering rate estimations. Tree species: Scots pine (Pinus sylvestris), Norway spruce (Picea abies).
Plot/ location Forest site type 1 Tree species Soil type 2 Soil texture Mafic
minerals (%)
0.06–2 mm 		Bedrock Bulk density
(g/cm3)
0–5 cm Undisturbed soil 		Stoniness
(%) 		Age of soil formation
(yrs) 3
Karkkila/
60°N, 24°E 		Oxalis-Myrtillus type spruce Cambic podzol Glacial till 25 Gabbro, diorite 1.0 (0.6) 4 30 10000
Tammela/
60°N, 23°E 		Vaccinium type pine Albic arenosol/
Haplic podzol 		Sand 12 Granitic 0.87 6 11500
Utti/
60°N, 26°E 		Myrtillus type spruce Haplic arenosol/
podzol 		Sand 7 Granitic 1.3 0 10500
Lapinjärvi/
60°N, 26°E 		Myrtillus type spruce Haplic arenosol/
podzol 		Sand 9 Granitic, gneisses 1.3 0 10500
Evo/
61°N, 25°E 		Myrtillus type spruce Haplic arenosol/
podzol 		Sand 17 Granitic, gneisses 0.89 0 10500
1 Cajander (1949)
2 FAO/WRB (Mustajärvi et al. 2008; Merilä et al. 2014; Adamczyk et al. 2016; Lindroos et al. 2016a; Lindroos et al. 2016b)
3 According to Tanskanen and Ilvesniemi (2004); Korhonen (2008); Törmänen (2016)
4 Mechanically disturbed soil (ploughing)
Table 2. Soil sample depths and soil horizons on the sample plots. Soil samples were taken from the soil horizons of the plots for element analysis and weathering rate estimations. Horizons sampled: E – eluvial horizon, B – illuvial horizon, BC – transition horizon between B and C, C – parent material.
Plot Horizon Depth (cm)
Karkkila E 0–4
B 4–10
B 10–20
BC 20–40+
Tammela E 0–3
B 3–6
BC 6–36
C 36+
Utti E 0–6
B 6–22
BC 22–44
C 44+
Lapinjärvi E 0–4
B 4–35
C 35+
Evo E 0–3
B 3–24
C 24+
1

Fig. 1. After ploughing, the topmost mineral soil layer in tilt and furrow is BC-horizon. BC horizon (depth 0–5 cm) sample was taken from disturbed parts of the soil and total concentrations were compared to those in undisturbed BC horizon. Sampling was performed 17 years after ploughing (Lindroos et al. 2016a).

2

Fig. 2. The CaO, MgO and Zr concentrations with depth in undisturbed soils of the sample plots (Utti, Lapinjärvi, Evo, Tammela, Karkkila), and in the disturbed soil in the Karkkila experiment.

3

Fig. 3. Weathering index (Wi) with depth in undisturbed soil of the sample plots.

4

Fig. 4. SiO2 × 10–3 / Zr ratio with depth in undisturbed soils of the sample plots.

5

Fig. 5. Weathering rates of Ca and Mg (E+B/BC horizons) in the undisturbed soils of the sample plots.

6

Fig. 6. The relationship between the mafic minerals and the concentrations of CaO and MgO in the C horizon on the sample plots. rs = Spearman’s rank correlation coefficient.

7

Fig. 7. The input of Ca and Mg in the soil (E+B/BC horizons) due to weathering in the sample plots during a period of 70 years (rotation period) in comparison to Ca and Mg amount in tree material in about 70-year-old spruce stands in southern Finland (Ukonmaanaho et al. 2008). Tree-total = nutrient amount in all above ground tree compartments. Tree-stem = nutrient amount in stem + bark.