Table 1. Characterization of Vaccinium uliginosum populations arranged by increasing plant surface area (study sites in italics were observed 2008–2010, others only in 2010).

Study site	Coordinates	Plant surface area (m2)	Surface area of the study site (m2)	Site perimeter (m)	Edge density (m−1)	Shrub cover (%)	Bog surface area (m2)	Surrounding forest (%)	Isolation (m)	Altitude(m)	Habitat
Grande Fange	50°14′40′’N 5°46′45′’E	81	213	69	0.32	38.2	1 295 000	62	1 130	557	Open, continuous to patchy; Lithalsa*, part of large fen
Wé des Pourceaux	50°14′40′’N 5°46′40′’E	97	97	48	0.50	100.0	172	100	610	602	Closed, continuous; Lithalsa*, part of Sacrawé reserve
Chamfa	50°13′07′’N 5°47′57′’E	193	9 059	437	0.05	2.1	446 700	56	1 130	563	Open, patchy, wet heathland
Robièfa	50°15′32′’N 5°41′59′’E	359	1 407	167	0.12	25.5	6 859	100	1 260	545	Closed, patchy, wet heathland
Pisserotte	50°13′10′’N 5°47′02′’E	394	10 500	403	0.04	3.8	180 600	96	1 010	572	Closed, patchy, wet heathland
Nazieufa	50°15′18′’N 5°43′00′’E	670	14 560	506	0.04	4.6	358 800	58	1 260	606	Open, patchy, wet heathland
Massotais	50°14′13′’N 5°45′34′’E	719	42 660	880	0.02	1.7	1 180 000	54	850	604	Open, patchy, bog with lithalsas*
Fange aux Mochettes	50°13′22′’N 5°40′54′’E	6 917	6 917	399	0.06	100.0	66 270	100	4 190	602	Closed, continuous, ombrotrophic bog
Sacrawé	50°14′40′’N 5°45′32′’E	31 580	51 400	1 094	0.02	61.4	548 100	78	610	600	Open, continuous to patchy, wet heathland

“Plant surface area” is the sum of the area covered by V. uliginosum shrubs. “Surface area of the study site” includes between shrub patches, “site perimeter” is the length of the edge of the study site. “Edge density” is the perimeter divided by surface of the study site. “Shrub cover” is “Plant surface area” per “surface area of the study site”. “Bog surface area” refers to the surrounding habitat, which is partly surrounded by forest plantations (“Surrounding forest”). “Isolation” is the distance to the nearest neighbouring study site. *Lithalsas are ramparted depressions covered with floating bog vegetation. Further explanations see text.