Table 1. Information on the sample plots. Remaining stand basal area (Gafter) in moderate (less intensive) and heavy (intensive) cutting was 17 and 12–13 m2 ha–1, respectively. Gbefore = stand basal area before cutting. n = number of sample plots. Drained peatland forest type (Laine et al. 2018), Rhtkg (I) and (II) = herb-rich types (I) and (II), Mtkg(I) = Vaccinium myrtillus type (I), Mtkg(I-) = more infertile border variant of Mtkg(I).
Municipality Treatment Gafter Gbefore n Site type
Heinävesi (Rouvanlehto) Control 22–23 22–23 2 Rhtkg(I)
Moderate 17 21–24 2 Rhtkg(I)
Heavy 12 22 2 Rhtkg(I)
Janakkala (Paroninkorpi) Control 22–30 22–30 5 Rhtkg(II)
Moderate 17 22–27 5 Rhtkg(II)
Heavy 12 23–31 5 Rhtkg(II)
Juuka (Vaarajoki) Control 20–22 20–22 2 Mtkg(I)
Moderate 17 19–24 2 Mtkg(I)
Heavy 12 25–29 2 Mtkg(I)
Multia (Havusuo) Control 25–28 25–28 2 Mtkg(I) – Mtkg(I-)
Heavy 13 29–31 2 Mtkg(I) – (Mtkg(I-)
Table 2. Two-way repeated measures ANOVA with treatment (thinning intensity) and year (time since harvest) as fixed factors on the percent cover of species groups and species in the cutting trials on drained peatlands (Eq. 1). F-values and corresponding p-values indicated by asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001) are presented only for the species groups and species with significant (p < 0.05) effects. For species abbreviations, see the text and Supplementary file S1.
Species groups or species Intercept Treatment Year Treatment × Year
TREES and SHRUBS 69.58** 2.34 8.41*** 3.20*
DWARF SHRUBS 486.22*** 0.29 37.33*** 8.01***
GRASSES and SEDGES 10.66* 4.12* 34.13*** 9.14***
HERBS 75.47** 0.17 15.10*** 5.51***
BRYALES 809.24*** 1.72 17.20*** 3.17*
SPHAGNUM 302.12*** 0.78 11.22*** 1.21
Betupube 28.54* 3.73* 4.88* 4.04**
Piceabie 26.18* 0.15 3.40* 1.12
Pinusylv 7.43* 2.32 5.85** 1.84
Rubuidae 25.76* 4.50* 19.68*** 5.80***
Sorbaucu 7.96 0.83 6.53** 0.50
Vaccmyrt 82.98** 0.15 49.48*** 5.44**
Vaccviti 36.19** 1.14 9.01*** 7.00***
Careglob 7.28 2.41 23.55*** 6.40***
Descflex 5.37 0.84 6.08** 1.02
Dryocart 185.00*** 0.41 35.25*** 2.73*
Epilangu 15.31*** 1.47 6.78** 3.55*
Linnbore 4.15 0.25 3.39* 2.86*
Maiabifo 3.45 0.33 7.61** 0.46
Melasylv 1.85 2.37 3.05 2.85*
Oxalacet 2.84 1.57 5.60** 4.00**
Trieeuro 10.76* 4.50* 17.10*** 3.62*
Bracspp 41.30* 1.02 7.72** 7.46***
Dicrmaju 26.18* 2.94 26.32*** 0.57
Hylosple 255.26*** 0.39 14.82*** 3.24*
Plagspp 2.20 0.39 9.23*** 1.46
Pleuschr 53.11** 0.55 11.63*** 3.63*
Sphagirg 12.17* 0.42 6.57** 1.86
Spharuss 6.70 0.39 7.55** 0.23
Litter 1088.50*** 0.87 22.30*** 2.85*
Number of species 690.35*** 0.42 4.17* 2.95*
1

Fig. 1. Box plots showing species group cover across treatment and year (two-way repeated ANOVA, Table 2). Significant pairwise comparisons among years are indicated with asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001). Treatments and stand basal area after cutting in 2016: no cutting (G = 20–30 m2 ha–1), moderate cutting (G = 17 m2 ha–1) and heavy cutting (G = 12–13 m2 ha–1).

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Fig. 2. Box plots showing the tree and shrub species cover across treatment and year (two-way repeated ANOVA, Table 2). Significant pairwise comparisons among years are indicated with asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001). Treatments and stand basal area after cutting in 2016: no cutting (G = 20–30 m2 ha–1), moderate cutting (G = 17 m2 ha–1) and heavy cutting (G = 12–13 m2 ha–1).

3

Fig. 3. Box plots showing grass and sedge and dwarf shrub species cover across treatment and year (two-way repeated ANOVA, Table 2). Significant pairwise comparisons among years are indicated with asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001). Treatments and stand basal area after cutting in 2016: no cutting (G = 20–30 m2 ha–1), moderate cutting (G = 17 m2 ha–1) and heavy cutting (G = 12–13 m2 ha–1).

4

Fig. 4. Box plots showing herb species cover across treatment and year (two-way repeated ANOVA, Table 2). Significant pairwise comparisons among years are indicated with asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001). Treatments and stand basal area after cutting in 2016: no cutting (G = 20–30 m2 ha–1), moderate cutting (G = 17 m2 ha–1) and heavy cutting (G = 12–13 m2 ha–1).

5

Fig. 5. Box plots showing the bryales and Sphagnum species cover across treatment and year (two-way repeated ANOVA, Table 2). Significant pairwise comparisons among years are indicated with asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001). Treatments and stand basal area after cutting in 2016: no cutting (G = 20–30 m2 ha–1), moderate cutting (G = 17 m2 ha–1) and heavy cutting (G = 12–13 m2 ha–1).