Distribution and habitat niches of 37 peatland Cyperaceae species across a broad geographic range in Canada

Abstract

The presence and absence of 37 Cyperaceae species found on 498 peatlands across Canada were examined along surface water chemistry, shade, height above the water table, and climatic gradients. A canonical correspondence analysis of the species distribution along the environmental gradients indicated that surface water chemistry and climate were highly correlated with the first and second axes and were the two most important gradients distinguishing among groups. The climatic gradient was further subdivided into western oceanic continental and eastern oceanic continental gradients. Height above the water table and shade were correlated to the third canonical correspondence analysis axis and were of secondary importance in explaining species distributions. A TWINSPAN analysis of the species separated them into eight groups: (1) widespread, obligate rich fen, wet, shade-tolerant species; (2) widespread rich fen preferential species; (3) continental and eastern oceanic, rich fen preferential, wet, shade-intolerant species; (4) widespread fen, wet, shade-intolerant species; (5) widespread bog or fen, shade-tolerant species; (6) widespread subcontinental and oceanic, bog or fen, shade-intolerant species; (7) eastern subcontinental and oceanic, poor fen preferential species; (8) western oceanic, bog and poor fen preferential, shade-intolerant species. Response surfaces were generated by quantifying the frequency of occurrence of representative species in each group along pH and height above the water table, shade and mean annual temperature, and mean annual total precipitation gradients. Frequency of occurrence values for several of the rarer species indicated that they were not limited by the number of suitable habitats analyzed in this study but by other factors such as competition, failure to establish, or dispersal. This study emphasizes the importance of habitat and climate in determining the local and regional diversity and distribution of the most common Cyperaceae on peatlands in Canada.

Phylogeny, Species Richness, and Ecological Specialization in Cyperaceae Tribe Cariceae

“…Much more ecological data is available for boreal and temperate peatland species than for any other group of sedges. Species of tribe Cariceae often make up 20-30% of the flora in these habitats and dominate large areas within them (Anderson et al, 1996;Gignac et al, 2004;Dabros & Waterway, 2008). Despite the large number of studies of peatlands in Canada (reviewed by Gignac et al, 2004), few studies focus explicitly on testing niche differentiation.…”

Biological diversity of peatlands in Canada

“…There are scientifi c studies of bryophyte diversity that include peatlands in continental western Canada Halsey et al, 2000;Vitt et al, 2003), and parts of eastern Canada (e.g., Vitt and Slack, 1975;Gauthier, 1980Gauthier, , 2001. There are far fewer studies on peatland vascular and non-vascular plants, which examine ecological interactions and compare communities across different regions and peatland types (e.g., Gignac et al, 2004). The information presented in this paper is a fi rst attempt to provide a broad assessment of biological diversity in Canadian peatlands with an emphasis on the plants.…”

Additions to the boreal flora of the Northwest Territories with a preliminary vascular flora of Scotty Creek

“…Specimen citations com prise only the first collector's name, collection number, and herbarium acronym. (Porsild and Cody 1980); 2, mostly found in lakes with at least 48.9 mg HCO 3 -/L in New England (Hellquist 1980); 3, typical of extreme-rich fens in Alberta (Vitt and Chee 1990); 4, prominent or common only on basic substrates in Northwest Territories (Timoney et al 1993); 5, preferring minerotrophic peatlands in Quebec (Garneau 2001); 6, preferring rich fens in Canada (Gignac et al 2004); 7, calcicolous or calciphilous in northern Quebec (Dignard 2007); 8, having an affinity for calcareous substrates in northern Quebec (Dignard 2011 …”