A classification of peatlands in eastern Newfoundland

Abstract

The peatlands of eastern Newfoundland have been classified into six morphological types. The separation of types is based on peat depth, botanical constituents and degree of humification of the different peat strata, surface vegetation, and surface contours relative to the surrounding topography. -- The following peatland types are described: -- 1. Raised Bog -- 2. Blanket Bog -- 3. Slope Bog -- 4. Basin Bog -- 5. Patterned Fen -- 6. Flat Fen -- The vegetation of these morphological peatland types has been classified into seven plant associations and four communities using the methods of the Zurich-Montpellier School of Phytosociology. These floristic units are listed below in their approximate order of minerotrophy: -- 1. Cladonio-Vaccinietum vitis-idaea - characteristic of dry health-like conditions on raised, blanket, slope and basin bog. -- 2. Kalmio-Sphagnetum fusci - characteristic of drier areas of raised, blanket, basin and slope bogs. -- 3. Calamagrostio-Sphagnetum fusci - represents the Sphagnum fuscum hummocks of fens. -- 4. Scirpo-Sphagnetum tenelli - represents the wet flats and hollows of raised, blanket, slope and basin bogs. -- 5. Scirpo-Sphagnetum subniti - this is the dominant vegetation type of slope bogs and occurs only on that morphological peatland type. -- 6. Betulo-Sphagnetum stricti - the dominant vegetation type of patterned fens and occurs only on that morphological peatland type. -- 7. Betulo-Thalictretum polygoni - represents the minerotrophic flat fens. -- 8. Nuphar variegatum Community - represents the deep, open pools of raised, blanket and basin bogs. -- 9. Sphagnum torreyanum Community - represents the shallow pools of raised, blanket and basin bogs. -- 10. Utricularia cornuta Community - represents the shallow mudflats of raised, blanket and basin bogs. -- 11. Drosera intermedia Community - represents the more nutrient-enriched pools of patterned and flat fens. -- Water samples from a bog pool, characterized by the Nuphar variegatum community, and from a fen pool within a Drosera intermedia community site, were analysed for comparative assessment of algal species composition. The fen pool algal populations included 41 species, the bog pool had 22 species. This result is indicative of differences in nutritive conditions between bog and fen habitats. -- The morphological and phytosociological classifications presented were prepared on basis of independent sets of criteria. Nevertheless, it was found that the two systems were complementary and that particular phytosociological units were characteristic of particular morphological peatland types as listed above. To further test the validity of the proposed phytosociological classification a series of nutrient analysis, soil thaw rates and soil pH determinations were obtained for selected peat soils underlying the major floristic units. Results of these analyses strengthened the validity of the classification.