The raised bogs of south-eastern Labrador, Canada: classification, distribution, vegetation and recent dynamics.

Concentric raised bogs occur at low altitudes along the southern coast, excentric and plateau bogs extend inland to slightly greater altitudes and higher latitudes, and patterned fens occupy most of the interior north to the tundra. The zonation is explained in terms of the effects of moisture surplus, soligenous water flow and physiography on mire development. Raised bogs are similar to oceanic mires, with an extensive ground cover of Cladonia spp., absence of trees on the mire expanse, and pronounced surface patterns of broad peat hummocks and open-water pools. Three floristic noda are recognized in the phytosociological table: C. stellaris-C. rangiferina-Kalmia angustifolia nodum on raised hummocks and Sphagnum rubellum-Scirpus cespitosus and Sphagnum lindbergii- Scirpus cespitosus noda in hollows. As a result of the extensive cover of lichens the hummock vegetation readily burns during lightning fires, which are prevalent on the uplands. The recent history of the hummock vegetation involves alteration of Cladonia stellaris and Sphagnum fuscum.-from Authors