Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the "cleanest", ancient peat samples ever tested from the northern hemisphere (ca. 6000-9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of "natural, background" values. The concentrations of "heavy metals" in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower.

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An efficient method for estimating bryophyte diversity in forest stands must consider more than just the dominant forest mesohabitat. We compared two methodologies commonly used for estimating diversity in forest ecosystems. Floristic habitat sampling (FHS) utilizes stratification of all forest mesohabitats, which includes the natural diversity of microhabitats found within and stratifies a mosaic of mesohabitats (e.g. forest, streams, seeps, and cliffs) and microhabitats (e.g. rocks logs, etc.) that are often not considered in forest research projects that use plot sampling to estimate species diversity. In Canadian cedar hemlock forest, FHS methodology recorded more than twice as many bryophyte species as plot sampling (PS). A comparison of the dominant forest mesohabitat concluded that plot sampling was not as efficient as FHS in estimating bryophyte diversity and that plot sampling can result in different interpretations of species diversity. Rare species ordination of stands sampled using FHS showed strong clustering of sites with respect to biogeoclimatic zones and age since the last major disturbance (fire or logging) as compared with rare species ordinations from PS data, which showed no delineation of stands along temporal gradients. Plot sampling has many useful applications in ecology, but floristic habitat sampling is more efficient for quantifying overall bryophyte diversity. FHS provides an excellent way to record a comprehensive list of species.

Mosses and hepatics (bryophytes) are the most diverse and abundant understorey vegetation within the Coastal Western Hemlock (CWH) and Interior Cedar-Hemlock (ICH) zones of British Columbia. This study intensively sampled bryophytes in 287 young-and old-growth stands in the CWH and ICH zones. Two major variables strongly influence the patterning of bryophyte diversity in these zones: stand age and habitat heterogeneity. Canonical correspondence analyses (CCA) identified these as the most important variables explaining stand-environment interactions. Alpha diversity is much greater in old-growth forests and beta diversity is high between young and old forests. Old-growth cedar-hemlock forests have between 60 (ICH) and 100% (CWH) more species than younger forests disturbed by wildfire in the ICH zones or logging in the CWH zones. Furthermore, a stand classification built on species composition partitioned species into stands of different ages and mesohabitat heterogeneity. Beta diversity was also partitioned between stands of different ages and habitat heterogeneity. This indicates that both young and old forests have a unique assemblage of species. Indicator analysis was used to choose a partial lists of species that are indicators of "old growthness". These old forests support a rich flora of hepatics and rare western North American endemics. High environmental continuity is associated with the most humid watersheds and cedar-hemlock forests within these watersheds have the highest bryophyte diversity. The establishment of rich communities of bryophytes in the moist cedar-hemlock forest has been occurring over the last 2000-7000 years, with the coastal rainforest much older than the inland rainforest. Large-scale disturbance, such as forestry, threatens the existence of these highly diverse communities. A better understanding of the patterning of bryophyte diversity will provide an opportunity to minimize the impact of forest operations on biodiversity. Bryophyte diversity in British Columbia cedar-hemlock forests will be sustained through ecosystem management of old-growth legacies (i.e., landscapes,