Supplemental Table S1. Description of the sampling sites.

Site name and location / Description and sampled microhabitats
B1. Golubino (unofficial name) 64°34’51.3”N, 43°18’23.8”E / Arkhangelsk oblast, 3 km to the NE of Golubino village, on the right bank of the Pinega River near the boundary of Pinezhsky Nature Reserve. Small (~1-1.5 ha) oligotrophic raised bog with Pinus-Eriophorum-shrublets-Sphagnum vegetation and weakly developed structure.
Sampled (13.08.2014): 1) “Sphagnum magellanicum” (3 samples): hummocks and mats with Chamaedaphne calyculata, Oxycoccus palustris, S. magellanicum, and some Sphagnum angustifolium. 2) “Sphagnum rubellum” (5 samples): hummocks with Andromeda polifolia, O. palustris and S. rubellum; Carex pauciflora-S. rubellum mat; Scheuzeria palustris-S. rubellum mats (also present Sphagnum cuspidatum and Sphagnum balticum). 3) “S. cuspidatum” (5 samples): waterlogged hollows with S. palustris, S. cuspidatum, and some S. balticum.
B2. Perschkovo (unofficial name)
64°28’56.5”N, 43°13’06.2”E / Arkhangelsk oblast, 2.8 km to the S of Perschkovo village, on the right bank of the Pinega River near the boundary of Pinezhsky Nature Reserve. Small (2-5 ha) raised Pinus silvestris-Sphagnum fuscum bog associated with a lake; the periphery is minerotrophic with ground water springs and high plant biodiversity.
Sampled (11.08.2014): 1) “S. magellanicum” (5 samples): Baeothryon caespitosum-S. magellanicum hollow; Carex rostrata-Rubus chamaemorus-A. polifolia-S. magellanicum hummocks; B. caespitosum-S. magellanicum mat. 2) “S. rubellum” (3 samples): Betula nana-Calluna vulgaris-S. rubellum hummocks.
B3. Krestenskoye
61°16’54.0”N, 36°25’00.2”E / Vologda oblast; a large (7076 ha) complex wetland system in the lower reaches of the Andoma River, dominated by meso-oligotrophic and oligotrophic peat bog; eutrophic and mesotrophic areas occur near the river. The mean depth of the peat layer is 2.21m (max 5.1 m). The vegetation is diverse, with 85 species of higher plants and more than 40 species of bryophytes. The bog is protected as a part of the Onezhsky Conservation Area.
Sampled (20.06.2014): 1) “S. magellanicum” (10 samples): A. polifolia-Sphagnum (S. fuscum-60%, S. magellanicum-10%, S. angustifolium-10%) hummocks; Eriophorum vaginatum-Sphagnum hummocks; O. palustris-Sphagnum hummock; Empetrum nigrum-Sphagnum hummock; Scheuzeria- Oxycoccus-Sphagnum mat. 2) “S. rubellum” (3 samples): A. polifolia-Sphagnum (S. fuscum + S. rubellum) hummocks; E. vaginatum-O. palustris-Sphagnum hummocks. 3) “S. cuspidatum” (10 samples): waterlogged hollow with S. palustris, Rhynchospora alba and Sphagnum (S. cuspidatum 75%, S. balticum 10-15%).
B4. Shichengskoye
59°56’30.4”N, 41°16’57.1”E / Vologda oblast; a large (15900 ha) wetland system of predominantly lacustrine origin, formed in the glacial lake basin. The central part is occupied by an oligotrophic lake (1060 ha). Significant areas are occupied by oligotrophic bog with Pinus-shrublets-Sphagnum and Eriophorum-shrublets-Sphagnum vegetation. The bog ridges and hummocks are dominated by S. fuscum, less frequently by S. angustifolium and S. magellanicum; hollows are occupied by S. cuspidatum, S. balticum, less frequently by Sphagnum majus and Sphagnum fallax. The south-eastern part of the bog system (where three rivers flow) is meso- and eutrophic. The eutrophic edges of the bog are forested with Betula pubescens, Salix pentandra, and Alnus glutinosa.
Sampled (18.07.2014): 1) “S. magellanicum” (5 samples): E. vaginatum-O. palustris-S. magellanicum hummock; Scheuzeria-Eriophorum-Sphagnum mat; C. calyculata-R. chamaemorus-Sphagnum (S. magellanicum 90% + S. fuscum) ridge; Scheuzeria-Sphagnum hollow. 2) “S. rubellum” (5 samples): hummocks and mats with E. vaginatum, O. palustris, A. polifolia, C. calyculata and S. rubellum. 3) “S. cuspidatum” (3 samples): Scheuzeria-Sphagnum hollow (S. majus-40%, S. cuspidatum-25%, S. balticum-15%, S. angustifolium-5%, S. magellanicum-5%).
B5. Alexeevskoye
59°27’10.9”N, 40°30’59.0”E / Vologda oblast; a regionally protected oligotrophic bog (1503 ha) located in undrained depression between Sukhona River and its tributaries. Originally formed through terrestrialization of a lake (a layer of sapropel with mean depth 0.46m covers ​​548ha), and then by paludification of surrounding forests. The bog has a pronounced structure of ridges, hummocks, and hollows. About 75% of the bog is open with sparse P. sylvestris. The bog edges and its southern part are meso-oligotrophic with more diverse vegetation. The oligotrophic part is dominated by E. vaginatum, Carex limosa, S. palustris, R. alba, Drosera rotundifolia, and C. calyculata and O. palustris shrublets; less common are R. chamaemorus, Drosera anglica, A. polifolia, Vaccinium uliginosum, Ledum palustre and Empetrum nigrum. Sphagnum layer is well developed (on hummocks and ridges: S. fuscum, S. magellanicum, S. angustifolium; in hollows: S. majus, S. balticum, S. fallax; in small pools: S. cuspidatum; on forested edges: Sphagnum riparium, Sphagnum russowii, Sphagnum squarrosum).
Sampled (20.07.2014): 1) “S. magellanicum” (5 samples): E. vaginatum-O. palustris-S. magellanicum hummocks. 2) “S. rubellum” (5 samples): A. polifolia-Sphagnum mat; A.polifolia-E. vaginatum-Sphagnum mat; R. alba-O. palustris-Sphagnum mats; O. palustris-S. rubellum hummock. 3) “S. cuspidatum” (5 samples): Carex-Scheuzeria-Sphagnum hollow; Scheuzeria-Sphagnum hollow; small pool (S. cuspidatum, water form).

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