Boreal plains peatlands: Characterization, plant diversity, biogeography, and impacts from logging (Manitoba)

This thesis examines peatland ecology under the following chapters: (2) The vegetational ecology of black spruce swamps, fens, and bogs in southern boreal Manitoba, Canada, (3) Plant diversity and rarity in the southern boreal peatlands of Manitoba, (4) Determinants of plant diversity and community change in western boreal wooded rich fens, and (5) Impacts of logging in the southern boreal peatlands of Duck Mountain, Manitoba, Canada. Chapter 2 focuses on a multivariate classification of 94 peatlands. Wooded and open moderate-rich fens are the dominant peatland types, and wooded bogs and open extreme-rich fens are rarer. Black spruce swamps were observed as a distinct peatland type. Bogs are differentiated from the other peatland types based on surface water chemistry, but the distinctions are less strong among the other types. Chapter 3 examines bryophyte and vascular plant species richness and rarity in peatlands from Chapter 2. Total diversity was 299, comprised of 87 bryophytes and 212 vascular plants. The highest diversity was found in wooded moderate-rich fens and black spruce swamps, whereas the lowest diversity was observed in wooded bogs and open extreme-rich fens. Rare plant diversity was greatest in wooded and open moderate-rich fens, and black spruce swamps. Plant richness was associated primarily with surface water chemistry and overstory density. Chapter 4 describes the relationship between plant richness/composition and environmental variables in wooded moderate-rich fens across Alberta, Saskatchewan, and Manitoba. Gamma diversity totaled 273, comprised of 86 bryophytes and 187 vascular plants. Alpha diversity decreased along a westward gradient. Bryophyte diversity was explained by location, and vascular plant diversity was predicted by location, elevation, and overstory density. Chapter 5 describes the impacts of logging on peatlands 1-4 and 9-12 years post harvest by comparing plots in clear-cut areas with plots in remaining wooded peatlands. Increased water temperature and nutrients were observed in clear-cut plots in the 1-4 year class. Regeneration of Picea mariana was unchanged between wooded and clear-cut plots, despite significantly higher numbers of shrub stems, exposed peat, and rutting in clear-cut plots. Vascular plant diversity was greatest in clear-cut plots and bryophyte/lichen diversity was greatest in wooded plots.