Wells Gray References

The importance of waterfalls and whitewater for lichen diversity is well known among field lichenologists but seldom has it been documented in the literature. We call attention here to a string of occurrences of eleven regionally rare lichens from waterfalls in inland British Columbia. Pseudocyphellaria mallota is reported as new to British Columbia and Haematomma ochroleucum new to Idaho. Psoroglaena stigonemoides is new to North America.

The occurrence of 24 species of epiphytic macrolichens, many of which have previously been assumed to have strictly coastal distributions in western Northern America, is documented for five humid forests in inland British Columbia. These lichens were detected only in very old forests, and appear to be essentially absent from younger forest types in this region. Oldgrowth forests possibly favour such species by reason of their rather equable microclimate and relative environmental stability. The possibility is raised that some species may be relicts from the “Little Ice Age”, when climatic conditions were presumably more favourable to long-distance dispersal by lichens outside their current primary ranges. Not all oldgrowth forests are equally rich in oldgrowth-dependent lichens. Diversity appears to be positively correlated with forest age or, more precisely, with environmental continuity., In support of this, it is observed that successful long-distance dispersal by oldgrowth-dependent lichens occurs only rarely; older oldgrowth forests can therefore be expected to support a fuller complement of such species than younger oldgrowth forests. The possibility is raised that oldgrowth-dependent lichens may provide a rough index of environmental continuity in the oldest of British Columbia’s inland forests. The term “antique” is applied to such forests. It is concluded that old oldgrowth forests (= “antique forests”) are more valuable for the purposes of lichen conservation than young oldgrowth forests.

The distributional ecology of the tree-dwelling “hair lichens” Bryoria fremontii and B. pseudofuscescens is examined based on observations in high elevation conifer forests of inland British Columbia. Seven obvious microscale and mesoscale patterns are reported for one or both of these species: (1) a failure to successfully colonize branches occurring below the upper limit of the winter snowpack; (2) an occurrence in much lower abundance over the outer, foliated portions of branches than over the inner, defoliated portions of the same branches; (3) a tendency to periodic die-off in the outer, foliated branches, but not in the inner, defoliated branches; (4) a development of disproportionately heavier loadings over old, senescent trees than over young, vigorously growing trees of similar size; (5) an ability to colonize all levels of the forest canopy, including the upper crowns of trees; (6) an anomalously higher biomass in young stands growing in exposed sites than in young stands growing in sheltered sites; and (7) a development of considerable biomass in poorly illuminated stands that are nevertheless well ventilated. Based on these observations, the main distributional features of these species, and of Bryoria as a whole, are assumed to reflect a pronounced sensitivity to prolonged wetting, especially as a result of snowmelt. Other environmental factors are apparently less important, at least in the study area.

British Columbia’s mountain caribou are behaviourally adapted to survival in regions of heavy snow. In winter when ground forage is buried out of reach, these animals subsist on a diet of tree-dwelling hair lichens. Caribou forage for hair lichens, especially Bryoria, in three contexts: 1) as litterfall; 2) in the crowns of recently windthrown trees; and 3) on the lower branches of standing trees. Litterfall and windthrown trees are especially important to caribou in their early winter habitats, often at lower elevations. The main winter range, however, is in the subalpine, and here they rely much more heavily on hair lichens growing on the branches of standing trees.

Bryoria biomass is heaviest in old-growth forests, where these lichens increase in abundance with increasing distance from the ground. Three vertical zones of abundance can be recognized:

• Zone A, in which Bryoria is virtually absent, is restricted to the basal portions of the canopy, its upper boundary (the “A/B threshold”) corresponding with the depth of the winter snowpack.

• Zone B is located directly above Zone A, and supports Bryoria at quite variable loadings, both spatially and temporally. The upward transition to Zone C is signalled by an abrupt increase in Bryoria abundance.

• Zone C is the zone of maximum Bryoria accumulation, especially on defoliated branches. Litterfall from Zone C contributes significantly to Bryoria biomass in Zone B, in part accounting for the highly variable Bryoria loadings characteristic of this zone.

Bryoria is unable to withstand prolonged burial by snow. Winters with exceptionally deep snowpacks cause upward shifts in the A/B threshold as buried Bryoria dies off. Thereafter, especially at subalpine elevations, the lower Bryoria trimline is likely to be situated well out of reach of caribou in early winter.

This can be predicted to delay the migration of caribou from their early winter habitat to their main winter range, because caribou are capable of foraging efficiently in subalpine forests only once deepening snows provide a feeding platform within about 1.5 – 2 m of the A/B threshold (or A/C in highly exposed sites).

Once elevated, an A/B threshold is slow to readjust downwards to its original position, requiring perhaps a decade or more. During this period, caribou can be predicted to spend more time than usual in their early-winter ranges, particularly in years when snowpacks are slow to build. Such years are probably highly stressful for caribou. Firstly, because these animals, effectively trapped at lower elevations, are at higher-than-average risk of encountering predators (owing to greater concentrations of other ungulates). Secondly, because as old-growth forests continue to be replaced by clearcuts, the likelihood of locating Bryoria-rich windthrown trees must also decline. Cratering for falsebox and other forbs of course provides some nourishment (less, however, in clearcuts than in forest settings), though the question needs to be raised whether the increasing lack of availability of hair lichens at lower elevations could result in food shortages for these animals.

The above Lichen-Snow-Caribou (LSC) hypothesis could provide a plausible explanation for the well-known tendency of caribou to perform annual vertical migrations much more pronounced in areas of heavy snows than in less snowy regions. It also suggests a framework against which to examine historic fluctuations in population size. In principle, caribou herds in areas of heavy snow ought to experience rapid episodic declines, followed by more gradual increases. Such declines, moreover, would be expected during the decade following a year of exceptionally deep snowpacks. Caribou populations in drier areas should be more stable.

To the extent that the LSC hypothesis is eventually validated, resource managers would do well to heed the warning implicit in it: low elevation old-growth forests may be crucial, at least in regions of heavy snow, to the long-term survival of mountain caribou. If so, then recent declines in the Revelstoke and Central Selkirk subpopulations could be simply an inevitable downward adjustment to existing conditions brought on by clearcut logging at the landscape scale.

Arboreal hair lichens belonging to the genus Bryoria provide crucial winter food for the threatened Mountain ecotype of the Woodland Caribou. Earlier studies suggest that the reliance of many Bryoria species on thallus fragmentation over a snow-covered subalpine meadow following a late winter windstorm of moderate force. Fragment densities were greatest immediately downwind of the forest edge, but remained substantial even at a distance of 2 km. This suggests that dispersal is not limiting for at least some Bryoria species at subalpine elevations. It is proposed that the ecological requirement of Bryoria fremontii and B. pseudofuscescens for well-ventilated habitats considerably enhances their ability to inoculate young, regenerating stands over considerable distances. Their observed general absence in young trees is probably a function of substrate limitations rather than of limitations of dispersal.

Three vertical zones of Bryoria abundance are recognized in the canopies of mid- and upper-elevation oldgrowth conifer forests in southern inland British Columbia. Zone A, with virtually no Bryoria, is restricted to the lower trunk and lowermost branches, where its upper boundary (the “A/B threshold”) corresponds roughly with the maximum settled depth of the winter snowpack. Zone B is located directly above Zone A, and supports Bryoria in variable amounts ranging from negligible to heavy; its upper boundary is defined by an abrupt increase in Bryoria at the “B/C threshold”. Above this is Zone C: a well ventilated region supporting maximum Bryoria loadings consisting predominantly of the nonsorediate species B. fremonti, B. pseudofuscescens, and Nodobryoria oregana. Bryoria loadings in Zone B benefit from litterfall from Zone C, in the absence of which, Zone B would predominantly support only the sorediate species B. fuscescens and B. glabra. Winters of exceptionally deep snow cause marked upward shifts in the A/B threshold, presumably resulting in reductions in the early-winter availability of Bryoria to Mountain Caribou. This is expected to prolong early-winter migrations to lower elevations, where Caribou depend on lichen-rich oldgrowth forests. The existence of such forests is hypothesized to be integral to the long-term maintenance of healthy Caribou populations.

The distribution and general ecology of 293 macrolichen taxa are recorded for approximately 600 000 ha of mountainous terrain in Wells Gray Provincial Park and its vicinity in south-central British Columbia, Canada. Thirty-one taxa are documented for the first time from British Columbia, including seven from Canada, and five (Leptogium subtile, Usnea wasmuthii, and the lichenicolous fungi Corticifraga fuckelii, Echinothecium reticulatum, and Refractothilum peltigerae) from North America. 74% of the taxa included are essentially circumpolar, whereas only 11% are restricted to North America, in most cases western North America. A high proportion (71%) of the latter group is accounted for by corticoles. The Bioclimatic Zone System is used to indicate zonal distribution for the lichen species considered. Summaries of total ranges in the northern hemisphere are also provided. Duration of snow cover is considered to play a critical role in the distribution of many species, particularly terricoles. Numerous primarily coastal, oceanic lichen species are found to occur in the study area, including Cavernularia hultenii, Cladonia umbricola, Dendriscocaulon intricatulum, Hypogymnia enteromorpha, Parmelia pseudosulcata, Peltigera pacifica, Platismatia norvegica, Polychidium dendriscum, Pseudocyphellaria anomala, Sticta limbata, and Normandina pulchella.

Hypogymnia metaphysodes was first described from Japan and Sakhalin, and later reported from western North America. Here we show that the North American material currently referred to H. metaphysodes differs from that species not only morphologically and chemically, but also in ascospore size and shape. We also show that the North American material is in fact heterogeneous, and can be assigned to two well-defined species here described as new: Hypogymnia recurva sp. nov. and H. wilfiana sp. nov. Both of these lichens contain distinctive secondary metabolites: vittatolic acid in the case of H. recurva, and 2-methylene-3-carboxy-18-hydroxynonadecanoic acid (“apinnatic acid”), reported here for the first time from Hypogymnia, in H. wilfiana. Both of our new species are so far known only from western North America, where they occur primarily as epiphytes on the branches of conifers. Hypogymnia metaphysodes s. str. has not yet been reliably reported from this region and should be excluded from the North American lichen flora.

Lichens in which a cyanobacterial partner occurs can be referred to as “cyanolichens.” Such species are potentially important contributors to the nitrogen budgets of some conifer forest ecosystems. In the intermontane forests of British Columbia, 31 epiphytic (tree-dwelling) cyanolichens are known to colonize conifers, including 12-species that can be considered rare or infrequent in the province as a whole. In this paper we present a simple key for predicting stand-level epiphytic cyanolichen diversity on conifers. The key is based on several readily mappable environmental factors and is useful at an operational scale. Maximum cyanolichen diversity is shown to occur in lowland old-growth rain forests established over nutrient-rich soils and subject to a rainfall pH above about 5.0. Such stands are generally restricted to the base of hill slopes in the wettest subzones of the Interior Cedar-Hemlock zone, where they not only support one of British Columbia’s richest assemblages of rare cyanolichens, but also themselves represent on of the province’s rarest and most endangered forest ecosystems. Further work is urgently needed.

The “dripzone effect” involves the above-ground transfer of nutrients – presumably in the form of leachates – from the upper crown of one tree species to the lower crown of another. In humid, poorly ventilated Picea stands, nutrient enrichment associated with Populus dripzones has been shown to promote the development of cyanolichens belonging to the Lobarion. Here we examine the same phenomenon in well-ventilated stands, in which members of the more xerophytic Xanthorion are favoured, while some species of the alectorioid lichen genus Bryoria are excluded. The latter phenomenon may partly account for the often discontinuous occurrence of Bryoria to many mixed conifer stands at lower elevations.

The mountain caribou is a threatened ecotype of the woodland caribou restricted to east-central and southeast British Columbia as well as adjacent portions of Washington and Idaho. In winter these animals forage almost exclusively on arboreal hair lichens, especially Bryoria. Here we examine the vertical and horizontal occurrence of hair lichens within the canopy of a mid-successional, mid-elevational forest dominated by Engelmann spruce and subalpine fir. Our study yielded five key findings: 1) all hair lichen species potentially important to caribou are present 60 yr after stand initiation; 2) low-biomass sorediate species (mostly B. fuscescens) predominate in the lower and middle canopies; 3) high-biomass non-sorediate species (mostly B. fremontii and B. pseudofuscescens) are most abundant in the upper canopy; 4) hair lichen biomass is higher in open stands than in closed stands; and 5) hair lichen loadings are low when compared with earlier reports from old-growth stands. The last finding apparently reflects – in the upper canopy – a lack of defoliated branches and – in the middle and lower canopies – humid, poorly ventilated conditions. We suggest that a judicial use of stand thinning could considerably augment the production of non-sorediate Bryoria species in defoliated portions of the middle canopy. Within the lower canopy, however, thinning is unlikely to increase Bryoria loadings, except as a result of inoculation from the middle canopy.

The terricolous lichen Peltigera chionophila sp. nov. is described from the western cordillera of North America. It can be distinguished from other members of the P. aphthosa group by its even lobe margins, its uniformly corticate apothecial reverses, its well-defined veins that darken gradually toward the thallus centre, and by ts strict occurrence in mountainous regions subject to heavy, prolonged snow cover. Comparisons of sequences of the Internal Transcriber Spacer of the nuclear ribosomal DNA repeat support the taxonomic distinctness of this species. A map of its global distribution is provided.

Hypogymnia canadensis Goward & McCune is described as a new species of lichenized fungi from the west coast of North America, ranging from southeastern Alaska to western Oregon, inland to southeastern British Columbia. In many respects similar to H. metaphysodes (Asahina) Rass., H. canadensis is distinguished from that species by an imbricate growth form, more open branching, lobe tips that readily become brown in exposed sites, a darker ceiling of the lobe cavity, and the presence of 3-hydroxyphysodic acid in the medulla (K+ slowly reddish brown). So far H. canadensis is known from conifers in cool suboceanic to oceanic climates.

The coastal temperate rain forests of north-western North America are internationally renowned as the archetypal expression of the temperate rain forest biome. Less well documented is the existence of somewhat similar forests 500 – 700 km inland on the windward slopes of the Columbia and Rocky Mountains. Here we attempt to show that these inland ‘wetbelt’ forests warrant rain forest status. We report three key findings: (1) 40% of oceanic, epiphytic macrolichens found in Pacific coastal rain forests occur also in inland regions; (2) epiphytic species richness decreases with decreasing latitude, such that roughly 70% of disjunct oceanic species are restricted to regions north of 51° N; and (3) the southward decline in lichen diversity is correlated with a parallel decrease in summer precipitation, but not with mean annual precipitation. Main conclusions: These observations are consistent with the recognition of an inland rain forest formation between 50 and 54° N. Inland rain forests represent a small, biologically significant ecosystem whose continued fragmentation and conversion to tree plantations warrant close scrutiny.

Mountain caribou (Rangifer tarandus caribou) in southeastern British Columbia subsist for most of the winter on arboreal hair lichen, mostly Bryoria sPages Foraging occurs mainly in old subalpine fir (Abies lasiocarpa) forests near treeline. Here, the lower limit of Bryoria in the canopy is dictated by snowpack depth because hair lichens die when buried in snow. Bryoria is often beyond the reach of caribou in early winter, prompting caribou to move downslope to where lichen occurs lower in the canopy and other foraging modes are possible. Snowpacks are normally deep enough by late winter that caribou can reach Bryoria where it is most abundant, at high elevations. Extending this to inter-annual comparisons, Bryoria should be less accessible during late winter of low-snow years following normal winters, or of normal to low-snow years after deep-snow winters. We hypothesized that when maximum snowpack in late winter is low relative to the deepest of the previous 5 years, mountain caribou will use lower elevations to facilitate foraging (“lichen-snow-caribou” or LSC hypothesis). We tested this with late-winter data from 13 subpopulations. In the dry climatic region generally and for minor snowfall differences in wet and very wet regions, caribou did not shift downslope or in fact were at higher elevations during relatively low-snow years, possibly reflecting the ease of locomotion. The LSC hypothesis was supported within wet and very wet regions when snowpacks were about 1 m or more lower than in recent years. Elevation declined by 300 m (median) to 600 m (25th percentile) for snowpack differences of at least 1.5 m. Greater use of lodgepole pine and western hemlock stands sometimes also occurred. Management strategies emphasizing subalpine fir stands near treeline should be re-examined to ensure protection of a broader range of winter habitats used by caribou under variable snowpack conditions.