South-central British Columbia Research Articles

Tracing Detrital Epidote Derived from Alteration Halos to Porphyry Cu Deposits in Glaciated Terrains: The Search for Covered Mineralization

Abstract Distal alteration related to porphyry Cu mineralization is typically characterized by an abundance of green minerals, such as epidote, tremolite, and chlorite, within the propylitic and sodic-calcic alteration zones and extends far outside (>1 km) the mineralized zone(s). Glacial erosion and dispersal derived from rocks affected by propylitic and sodic-calcic alteration have resulted in the development of extensive dispersal trains of epidote in till (glacial sediment) that can reach 8 to 330 km2 as observed at four porphyry Cu study sites in the Quesnel terrane of south-central British Columbia: Highland Valley Copper, Gibraltar, Mount Polley, and Woodjam deposits. At each of these sites, epidote is more abundant in heavy mineral concentrates of till collected directly over and down-ice from mineralization and associated alteration. Epidote grains in till with >0.6 ppm Sb and >8 ppm As (as determined by laser ablation-inductively coupled plasma-mass spectrometry) are attributed to a porphyry alteration provenance. There is a greater abundance of epidote grains with high concentrations of trace elements (>12 ppm Cu, >2,700 ppm Mn, >7 ppm Zn, and >37 ppm Pb) in each porphyry district compared to background regions. This trace element signature recorded in till epidote grains is heterogeneously distributed in these districts and is interpreted to reflect varying degrees of metal enrichment from a porphyry fluid source. Tracing the source of the epidote in the till (i.e., geochemically tying it to porphyry-related propylitic and/or sodic-calcic alteration), coupled with porphyry vectoring tools in bedrock, will aid in the detection of concealed porphyry Cu mineralization in glaciated terrains.

A review of the Stelidium group of Stelis Panzer, 1806 (Hymenoptera: Megachilidae) with two new species from western North America.

The Stelidium group is readily distinguished from all other members of the subgenus Stelis Panzer, 1806 by the combination of small body size ( 6 mm), pale maculations on the head adjacent to the inner margins of the compound eyes and laterally on the vertex in both sexes, and females with sternum 6 extended beyond tergum 6, the former with the dorsal lip trowel-shaped with the apex broadly rounded or subtruncate to more narrowly pointed. This monophyletic clade, which is endemic to North America, currently consists of members previously placed into two species groups: the permaculata group containing S. anasazi Parker & Griswold, 2013, S. ashmeadiellae Timberlake, 1941, S. permaculata Cockerell, 1898, and S. robertsoni Timberlake, 1941, and the palmarum group containing S. broemelingi Parker & Griswold, 2013, S. elongativentris Parker, 1987, and S. palmarum Timberlake, 1941; two additional species, S. herberti (Cockerell, 1916) from Mexico, and S. nyssonoides (Brues, 1903) from Texas, United States, have not been definitively placed in either species group. Two new species are herein described, one from southcentral British Columbia, Canada, the other from New Mexico, United States. A preliminary molecular phylogeny places both new species in the permaculata species group. In addition, S. herberti is also placed within the permaculata species group based on morphological similarity, sharing the multi-spotted maculation pattern on the terga. Based on molecular affinity, S. broemelingi also belongs to the permaculata species group. Because no type specimen for S. nyssonoides is seemingly available for examination, it is hereby considered nomen dubium until the specimen is found and its taxonomic status clarified in relation to the more recently described species in the permaculata species group. A key to females and diagnoses are provided for all known taxa.

Biotic-Abiotic Radial-Acicular Crystal Fan Fabrics with Rosickýite at the Angel Springs Tufa-Travertine Deposit in Southern British Columbia

Abstract The tufa-travertine deposit at Angel Springs developed through the interaction of thermal waters with bedrock of the Proterozoic Okanagan Gneiss, which extends along the eastern margin of the Okanagan Valley fault system in south-central British Columbia. This warm spring is proximal to Miocene plateau basalt flows that cut the Okanagan Gneiss bedrock eastward of the Okanagan Valley. The carbonate deposit, which is widely referenced as tufa, consists of a tufa and an overlying travertine. These texturally and petrographically different deposits developed in response to a shift in the groundwater pathway wherein the surface discharge transitioned from multiple vents of the tufa to a single downslope vent pool of the overlying travertine. Lower interval tufa fabrics are characterized by networks of fenestral-type porosity supported by a framework of curvilinear stromatolitic sheets of calcite that resulted from the partial coalescence of sub-horizontal arrays of calcite-encrusted cyanobacteria. These tufa fabrics aligned with the strong stream flow emanating from multiple vents. In contrast, radial crystal fan fabrics of the upper interval travertine developed with the transition from biotic calcite encrustations of upward branching cyanobacteria to the abiotic development of radial crystal fans. Length-long mouldic porosity tubules were occluded as the abiotic sheaf- and fan-shaped crystal growth surfaces expanded radially with rapid degassing. Core areas of the radial crystal arrays coalesced and were partially recrystallized, resulting in spheroidal crystalline fabrics that preserve inclusion-delineated concentric growth surfaces. Syntaxial overgrowths of radially aligned acicular crystals rapidly expanded from these core areas of coalesced calcite, resulting in the formation of abiotic radial-acicular and starburst crystal arrangements. The biotic–abiotic transition resulted in the rapid growth of abiotic crystal fans as the dominant deposition process of the upper interval travertine fabrics, but not in the lower interval tufa fabrics. Activities of sulfate-reducing bacteria in the sulfate-rich thermal water of both intervals resulted in precipitation of rosickýite, the monoclinic polymorph of S, as nanocrystalline globular protuberances on surfaces of calcite crystals. This is the first recorded occurrence of rosickýite in a tufa-travertine deposit and the first recognition of this mineral in Canada.

Can Moisture-Indicating Understory Plants Be Used to Predict Survivorship of Large Lodgepole Pine Trees During Severe Outbreaks of Mountain Pine Beetle?

Abstract Why do some mature lodgepole pines survive mountain pine beetle outbreaks while most are killed? Here we test the hypothesis that mature trees growing in sites with vascular plant indicators of high relative soil moisture are more likely to survive mountain pine beetle outbreaks than mature trees associated with indicators of lower relative soil moisture. Working in the Clearwater Valley of south central British Columbia, we inventoried understory plants growing near large-diameter and small-diameter survivors and nonsurvivors of a mountain pine beetle outbreak in the mid-2000s. When key understory species were ranked according to their accepted soil moisture indicator value, a significant positive correlation was found between survivorship in large-diameter pine and inferred relative high soil moisture status—a finding consistent with the well-documented importance of soil moisture in the mobilization of defense compounds in lodgepole pine. We suggest that indicators of soil moisture may be useful in predicting the survival of large pine trees in future pine beetle outbreaks. Study Implications: A recent outbreak of the mountain pine beetle resulted in unprecedented levels of lodgepole pine mortality across southern inland British Columbia. Here, we use moisture-dependent understory plants to show that large lodgepole pine trees growing in sites with high relative moisture are more likely than similar trees in drier sites to survive severe outbreaks of mountain pine beetle—a finding that may be related to a superior ability to mobilize chemical defense compounds compared with drought-stressed trees.

Woody debris structures on large clearcut openings: Oases for small mustelids and prey species?

Restoration structures such as post-harvest woody debris piles on large clearcut openings may provide habitat for many mammal species. Mustelids such as the American marten (Martes americana) and several weasel (Mustela spp.) species are important furbearers in temperate and boreal forests and are negatively affected by clearcutting. We ask if constructed piles of woody debris on large (e.g., 30–50 ha) openings will be used by these mustelids and their small mammal prey species? We tested the hypotheses (H) that (H1) the presence (index of activity patterns) of small mustelids, (H2) abundance, species richness, and species diversity of the forest-floor small mammal community, and (H3) reproduction of the major species: southern red-backed vole (Clethrionomys gapperi), long-tailed vole (Microtus longicaudus), and deer mouse (Peromyscus maniculatus), would be greater on sites with woody debris piles than on sites with dispersed debris. A fourth hypothesis (H4) predicted that the above response variables would be similar across a linear configuration of debris piles on the large openings. Mustelid presence and populations of forest-floor small mammals were sampled on four replicated (n = 4) large (30–50 ha) clearcut sites from 2017 to 2022 in south-central British Columbia, Canada.Mean presence of mustelids was significantly higher (4.5 to 8.0 times) in piles than dispersed sites during the first four post-harvest years, thereby supporting H1. Mean index of mustelid activity per line was similar among pile index-lines across these clearcut openings. Mean abundance of C. gapperi was similar statistically between treatment sites but with numbers 3 to 10 times higher, on average, in the piles than dispersed sites and was likely biologically important. Mean abundance of M. longicaudus was significantly higher (1.2–4.4 times) in the piles than dispersed sites. Mean abundance of P. maniculatus and Sorex spp. were similar between treatment sites. Mean abundance of total small mammals, including the less common species, was significantly higher (1.4–1.9 times) in piles than dispersed sites. Similarly, mean species richness and diversity were both significantly higher in piles than dispersed sites. Mean number of total recruits was higher in piles than dispersed sites for M. longicaudus and P. maniculatus, but most measures of reproductive attributes were similar, thereby providing only partial support for H3. As per support for H4, response variables were similar across a linear array of debris piles on large openings. Our study is the first to measure responses of small mustelids and forest-floor small mammals to constructed piles of woody debris as a means of habitat restoration on relatively large (mean area 40.5 ha) openings created by conventional clearcutting. Piles of debris seem to act as oases for mustelids and their prey species in ecological restoration of cutover forest land.

Bacteria Isolated from Canada’s White Rabbit Cave Revealed Antimicrobial Activities

Caves offer a unique habitat for microorganisms, which allow the adaptation of exclusive metabolic pathways to the resources available. This environment could enable the production of primary and secondary metabolites with unique antimicrobial or enzymatic properties. White Rabbit Cave is located in the Monashee Mountain range in south-central British Columbia, a metamorphic range not known for cave and karst development. The present study has recovered bacterial isolates from the White Rabbit Cave and assessed them for their antimicrobial properties by employing the agar plug assay. One hundred and six bacterial isolates were cultivated from the collected samples, among which, five bacterial isolates displayed antimicrobial properties against a methicillin-resistant Staphylococcus aureus (MRSA) strain. Furthermore, these five isolates were identified with 16S rRNA gene sequencing and through phylogenetic analysis. It has been observed that three of them (B076, B053, and B079) were identified as Streptomyces spp. (Phylum Actinobacteria) while the other two were recognized as Paenibacillus spp. (B039) and Paenibacillus terrae (B016) (Phylum Firmicutes). To the best of our knowledge, this is the first study that identifies bacterial species with antimicrobial properties from White Rabbit Cave in the Monashee Mountain range in British Columbia, Canada.

Sunscreening pigments shape the horizontal distribution of pendent hair lichens in the lower canopy of unmanaged coniferous forests

AbstractHair lichens are distinctive for their capillary growth and typically arboreal occurrence, especially in temperate and boreal forests. They consist of two morphogroups based on cortical pigments: a brown-black group with fungal melanin and a pale yellow-green group with usnic acid. Here we test the hypothesis that these morphogroups are ecologically distinct and thus appropriately regarded as functional groups. We examine their respective horizontal occurrence in the lower canopy of 60-year-old conifer forests on a 250 m tall volcanic cone in south-central British Columbia. Trees on open south-facing slopes and near the summit were found to support mainly melanic hair lichens (Bryoria and Nodobryoria), whereas more densely spaced trees on north-facing slopes and at the base had higher cover values of usnic lichens (especially Alectoria sarmentosa and Ramalina thrausta). The cover of melanic hair lichens was strongly correlated with canopy openness but not for their usnic counterparts. We suggest that investment in light-absorbing melanic pigments is an extreme form of specialization for high light, favouring persistence in dry, sun-exposed canopies of otherwise cool forests. By contrast, the cortex of pendent usnic hair lichens appears to facilitate optimum light transmission to underlying photobionts in shaded sites, though at the cost of sensitivity to light in open habitats, especially in rather dry regions.

Polybaric magmatic evolution of the eocene penticton group alkaline rocks, south-central British Columbia

Volcanic rocks of the Challis-Kamloops belt erupted during the Eocene (55–45 Ma) throughout south-central British Columbia, Idaho, and Wyoming of the North American Cordillera. The Eocene volcanic rocks of southern British Columbia can be subdivided into three distinct groups (Kamloops, Princeton, Penticton) based on geography and composition. The southernmost Penticton Group is unique as it is composed of volcanic and intrusive alkaline rocks (e.g., Marron Formation, Terrace Mountain outlier, Allendale Lake pluton) as opposed to calc-alkaline rocks that are typical of the Kamloops and Princeton groups to the north. The rocks of this study are from the Penticton Group, are compositionally variably (SiO 2 = 51.2–64.7 wt%), and have highly fractionated chondrite-normalized REE patterns (La N /Yb N = 71–104) without noticeable negative Eu-anomalies (Eu/Eu* = 0.81–1.00). The rocks have similar Sr-Nd isotopic ( 87 Sr/ 86 Sr i = 0.706422–0.706563; ε Nd ( t ) = −4.3–6.1) ratios and Neoproterozoic depleted mantle model ages (T DM = 794–873 Ma). Petrological modeling demonstrates that the primary process of chemical differentiation within the Penticton Group is fractional crystallization. However, it appears that the Marron, Allendale Lake, and Terrace rocks underwent fractional crystallization at different pressures (i.e., 4 GPa, 1.5 GPa, and 1 GPa). The polybaric differentiation of the Penticton Group indicates that the alkaline system evolved at different crustal depths in a similar manner as magmas related to the Yellowstone hotspot and markedly different from the Kamloops and Princeton groups. We suggest that the Penticton Group is underlain by ancient lithospheric mantle that was modified by Precambrian subduction processes and was isolated from the convecting mantle whereas the northern part of the Eocene volcanic belt is underlain by exotic accreted terranes (Intermontane Superterrane) and was derived from a different, younger lithospheric mantle. • The Penticton Group alkaline rocks were emplaced during the Eocene (∼50 Ma). • The primary process of chemical differentiation is fractional crystallization. • Differentiation occurred under variable pressure at a post-collisional setting. • The magmas were derived from the ancient lithospheric mantle of North America.

Long-Term Changes in Abundance and Composition of Forest-Floor Small Mammal Communities in a Landscape with Cumulative Clearcutting

Responses of forest-floor small mammals to clearcutting are species-specific with generalists occupying a range of habitats, and specialists persisting on clearcuts for variable periods. We investigated the responses in abundance and species composition of small mammal communities to cumulative clearcutting of coniferous forests on a landscape that had four independent clearcutting events (Periods 1 to 4) over a 42-year interval from 1979 to 2020 in south-central British Columbia, Canada. We ask if the small mammal communities have changed significantly over these decades owing to removal of old-growth forest by clearcut harvesting. Hypotheses (H) predicted that the small mammal community would (H1) increase in abundance, species richness, and diversity on new clearcuts owing to the availability of early seral post-harvest habitats from cumulative clearcutting; and (H2) have higher mean abundance, species richness, and species diversity in clearcut than uncut forest sites, owing to availability of vegetative food and cover. A third hypothesis (H3) predicted that abundance of (i) early seral vegetation (herbs and shrubs) and (ii) small mammal populations, will be greater in ungrazed clearcut sites than in those grazed by cattle (Bos taurus). Mean total numbers of small mammals on new clearcuts declined in Periods 3 and 4, and hence did not support the abundance part of H1. Much of this decline was owing to low numbers of the long-tailed vole (Microtus longicaudus) and meadow vole (M. pennsylvanicus). Two generalist species: the deer mouse (Peromyscus maniculatus) and northwestern chipmunk (Neotamias amoenus), contributed to high mean species richness and diversity in Periods 2 and 3 before these metrics declined in Period 4, and hence partly supported H1. The similarity in mean total numbers of small mammals in Periods 2 to 4 did not support the abundance prediction of H2 that total numbers would be higher in clearcut than uncut forest sites. Higher mean species richness (Periods 2 and 3) and diversity (Period 3) measurements on clearcut than forest sites, particularly in the early post-harvest years, did support these parts of H2. The vegetation part (i) of H3 was not supported for herbaceous plants but it was for shrubs. The small mammal part (ii) of H3 that populations would be higher in ungrazed than grazed clearcut sites was supported for abundance but not for species richness or diversity. The decline and near disappearance of both species of Microtus was possibly related to the reduction in plant community abundance and structure from grazing (at least for shrubs) and potentially from drought effects associated with climate change. Loss of microtines from these early seral ecosystems may have profound negative effects on various ecological functions and predator communities.

Identifying and analyzing spatial and temporal patterns of lightning-ignited wildfires in Western Canada from 1981 to 2018

To assess wildfire risk linked to lightning-caused wildfires, the present study tests the spatial- and temporal-scale distribution variability of lightning fires in Western Canada between 1981 and 2018. We examined clustering, trends, distances between clusters, and the fire season. For this study, the nearest neighbours, K-function, Moran's I, Mann–Kendall, and the Getis-ord Gi* statistics were used. These statistics were visualized by a Space Time Cube model with a hexagon grid. Lightning-ignited wildfires cluster spatially up to 270 km with an observed overall nonsignificant decreasing trend for the number of fires. Overall, northeastern Alberta, central Saskatchewan, and southeastern British Columbia show clustering of lightning fires. In June, there is significant clustering in northwestern and eastern Alberta, while in July fires cluster in northeastern Alberta and in southeastern British Columbia. In August, fire clusters occurred only in southeastern and south-central British Columbia. These results highlight regions that are experiencing persistent lightning fire clustering activity. This provides a focal point to assess wildfire risk to communities and values at risk, while informing local and regional management agencies in preparedness, resource capacity management, and detection. Additionally, it provides a baseline for future research into biophysical modelling of wildfire initiations.

The importance of effective moisture and landscape controls on diatom assemblages and primary production in Roche Lake, British Columbia, Canada over the past ca. 1800 years

AbstractLakes in the semiarid Southern Interior Plateau of British Columbia, Canada are vulnerable to future climate-driven changes in water quantity and quality. However, few long-term monitoring records exist to assess the effects of varying hydroclimate conditions on lake function. We present a high-resolution multiproxy paleolimnological record containing subfossil diatoms, μXRF via ITRAX, and chlorophyll-athat spans the past 1800 years from Roche Lake in south-central British Columbia. Generalized additive models indicate that the diatom assemblages were associated with changes in lake level and the accompanying effects of atmospheric forcing on lake thermal structure, and that these forcing mechanisms had a weak relationship with primary production. We infer two pronounced arid periods between ca. AD 600–950 and ca. AD 1730–1950 that correspond to evidence of reduced lake mixing and enhanced anoxia, but variable patterns in primary production. Synthesis of regional proxy records suggests that inferences of moist but possibly warm conditions during the Medieval Climate Anomaly may have occurred because of a complex interaction between prolonged La Niña-like conditions and higher radiative forcing. Overall, lakes in this region are sensitive to changes in hydroclimate generated by interactions between external forcing and Pacific Ocean–atmosphere processes, and the resulting changes in aridity may have potentially negative consequences on salmonid habitat.

Stand openness predicts hair lichen (Bryoria) abundance in the lower canopy, with implications for the conservation of Canada’s critically imperiled Deep-Snow Mountain Caribou (Rangifer tarandus caribou)

Tree-dwelling hair lichens in the genus Bryoria provide crucial late-winter forage for Deep-Snow Mountain Caribou (DSC), an imperiled ungulate endemic to south-central British Columbia, Canada. Because DSC survival requires continuous access to heavy hair lichen loadings, conservation efforts can benefit from an improved understanding of the factors that contribute to such loadings. Here we quantify the relation of Bryoria abundance to stand spacing by testing an “Angle-To-Canopy-Skyline” (ATCS) protocol as a measure of stand openness and a proxy for ventilation. Fieldwork conducted in 60-year-old conifer forests on a 250-m conical volcano within the range of DSC yielded three principal findings: (1) Bryoria abundance strongly increases with increasing stand openness; (2) Pinus contorta supports much heavier Bryoria loadings than other local host trees; and (3) ATCS is a powerful predictor of arboreal hair lichen abundance in general across a wide range of environmental settings, but does not predict the abundance of foliose lichens. We suggest that canopy openness, at least within the range of DSC, complements stand age as a key factor in the development of heavy Bryoria loadings, consistent with the hypothesis that Bryoria benefits from rapid drying after rain. The possibility that anomalously high Bryoria abundance on Pinus may hold promise for accelerated DSC habitat restoration following clearcut logging is explored but rejected.

Eocene Volcanic Complex from Central British Columbia: The Role of Fractional Crystallization during the Magmatic Evolution

Abstract The Challis-Kamloops belt of south-central British Columbia is a regionally extensive (>65,000 km2) magmatic province that erupted within the North American Cordillera during the Eocene (55-45 Ma). The inland volcanic belt runs parallel to the coast, and the rocks were emplaced mainly within extensional basins indicating volcanism was attributed to rift-related decompressional melting. The rocks include both calc-alkaline and tholeiitic mafic and intermediate types (i.e., low-Fe, medium-Fe, and high-Fe suites). Voluminous volcanic units (Buck Creek, Goosly Lake, Swans Lake) of the Buck Creek volcanic complex (~3,000 km2 in area) within the Nechako plateau erupted within 1-2 million years and show significant internal chemical variability. All rock types have similar Sr-Nd isotopic (87Sr/86Sri=0.70435-0.70487; εNdt=+2.6-+4.0) ratios indicating they originated from the same sub-Cordilleran mantle source. Petrological modeling using the most primitive rocks of the Buck Creek, Goosly Lake, and Swans Lake magmatic pulses demonstrates that the chemical variability observed in each system can be explained by hydrous fractional crystallization in the upper crust (≤0.1 GPa) under moderately oxidizing to oxidizing conditions (ΔFMQ 0 to +0.7). The primary difference between the low-Fe to medium-Fe (calc-alkaline) Buck Creek suite model and the high-Fe to medium-Fe (tholeiitic) Swans Lake suite model is water content as the Swans Lake model has lower (H2O=0.75 wt.%) starting water than the Buck Creek and also the Goosly Lake models (H2O=1.25-2.00 wt.%). Moreover, the intermediate to silicic rocks of the complexes are compositionally similar to rocks associated with “slab failure” suggesting that rifting and mantle melting were related to asthenospheric upwelling through a slab tear. The implications are that the chemical variability of the rock suites are primarily related to fractional crystallization and that the mantle source is heterogeneous with respect to water content which is likely due to heterogeneities in the processes related to pre-Eocene subduction.

Long-term demographic changes of deer mouse (Peromyscus maniculatus) populations in a forest landscape with cumulative clearcutting

The deer mouse (Peromyscus maniculatus) is a generalist species and is widespread among the various early-successional forest habitats associated with post-clearcut landscapes. Deer mice seem to occupy clearcuts more than undisturbed late successional forest, at least for abundance, because harvested sites apparently act as dispersal sinks. We investigated the responses in abundance of P. maniculatus populations to cumulative clearcutting of coniferous forests on a landscape that had four independent clearcutting events (Periods 1 to 4) over a 42-year interval from 1979 to 2020 in south-central British Columbia, Canada. We tested three hypotheses (H) that populations of P. maniculatus would (H1) increase in abundance owing to the ongoing availability of early seral post-harvest habitats associated with cumulative clearcutting; (H2) have higher mean abundance, reproduction, and survival in clearcut than forest sites owing to greater food resources; and (H3) occupy clearcut sites as dispersal sinks thereby having lower adult body mass (a proximate measure of condition) and reduced reproductive output than in forest sites.Mean annual abundance of P. maniculatus was highest and similar in Periods 2 and 4 with comparable numbers in Period 1 for the first four post-harvest years of these clearcutting periods. This pattern did not support H1 that P. maniculatus would increase in abundance associated with cumulative clearcutting over the 42-year period. Deer mouse populations reached relatively high densities (range of 23 to 53 per ha) on clearcut sites and these irruptions were likely related to supply of lodgepole pine seed from cones in logging debris. Overall mean abundance of P. maniculatus ranged from 1.4 to 3.6 times higher in clearcut than forest sites, thereby supporting the abundance part of H2. Recruitment, number of successful pregnancies, and breeding young-of-the-year deer mice were all higher in clearcut than forest sites, thereby supporting the reproduction part of H2. However, equivocal measures of overall survival did not support this hypothesis. The general similarity in mean body mass of adult mice between treatment sites and higher reproductive output in clearcut than forest sites did not support H3 that clearcut sites would act as dispersal sinks for deer mice. This study is the first to measure the long-term demographic responses of deer mice to cumulative clearcutting over a coniferous forest landscape. Clearcut sites may provide high-quality habitat for deer mice in this forest landscape.

Detecting Buried Porphyry Cu Mineralization in a Glaciated Landscape: A Case Study from the Gibraltar Cu-Mo Deposit, British Columbia, Canada

Abstract At the Gibraltar porphyry Cu-Mo deposit in south-central British Columbia, Canada, geochemical and mineralogical anomalies in till around a cluster of mineral occurrences form amoeboid-shaped dispersal patterns controlled by three phases of ice movement. The glacial dispersal patterns defined by elevated concentrations of ore (Cu, Mo) and pathfinder (Ag, Zn) elements and alteration oxides (Al2O3, K2O) in the till matrix (clay and silt plus clay fractions) extend over areas of 6–36 km2 and are centered on the main economic mineralization. Mineralogical dispersal trains were identified by the high abundances of chalcopyrite, pyrite, jarosite, titanite, and epidote, which were derived from the mineralization and its associated oxidation and alteration zones. These mineralogical anomalies in till extend approximately 30 km2 for chalcopyrite, 62 km2 for jarosite, and up to 136 km2 for epidote. Epidote grains in till with a trace element composition of >10 ppm As, >4 ppm Sb, <200 ppm total rare earth elements (ΣREEs), <45 ppm Y, <100 ppm Sc + Cr + Y, and/or <2 ppm Th + Hf are interpreted as being either principally derived from the intrusive rocks or from hydrothermal alteration of the porphyry mineralization. Rare epidote grains with >30 ppm Cu, interpreted to be related to the porphyry Cu mineralization, were detected in till up to 7 km down-ice from the economic mineralization. This study demonstrates that till geochemistry and mineralogy, combined with geochemical analyses of specific minerals such as epidote, are efficient methods for identifying porphyry Cu mineralization in terrains covered by glacial sediments.

Abundance, Distribution and Migration Patterns of North American Eared Grebes (Podiceps nigricollis)

Most North American Eared Grebes (Podiceps nigricollis) undertake a post-breeding migration to two hypersaline lakes in the USA: Mono Lake in California and Great Salt Lake in Utah. Single air photo surveys were conducted in mid-October at Mono Lake from 1996-2012 and multiple fall surveys were conducted from 2013-2018, the latter to determine variation in abundance patterns within and across years. In four of the six years with multiple fall surveys, peak abundance occurred in mid-October as expected. However, in 2014 and 2015, Eared Grebe numbers declined dramatically soon after arrival, coinciding with low levels of their primary food, brine shrimp (Artemia monica). Abundance remained low from 2016-2018, and this could have been due to a shift to Great Salt Lake or to a massive mortality event. In 2017 and 2018, Eared Grebes breeding in south-central British Columbia, Canada were marked with Very High Frequency (VHF) radio transmitters and light-level geolocator (GLS) tags. Contrary to 1996, when the majority of VHF-tagged birds were molting/staging on Mono Lake, our 2017-2018 telemetry data indicated that most individuals were on Great Salt Lake. Our study provides insight into the variable abundance patterns at Mono Lake and novel information on Eared Grebe migration patterns.

Brewsterite-Sr, Wakefieldite-(Ce), and Associated Minerals From the Marron Volcanics of the Olalla Area, South-Central British Columbia, Canada

The Marron Volcanics of South-Central British Columbia are host to a suite of zeolites and other minerals, the most significant of which are brewsterite-Sr and wakefieldite-(Ce). The top specimens ...

Canopy throughfall links canopy epiphytes to terrestrial vegetation in pristine conifer forests

To what extent does epiphytic community composition in boreal forests reflect soil nutrient status? To answer this question, we investigated potential links between terrestrial plants and lichen-dominated communities in Picea glauca x engelmannii canopies in south-central British Columbia. We combined original data on vegetational composition in the ground and tree layers with published data on elemental uptake in standardized transplants of the lichen Lobaria pumonaria affixed to the lower branches of studied trees. Procrustean association metrics revealed a significant concordance between community composition among the epiphytic and terrestrial vegetation, which was stronger in Mn-enriched conifer canopy settings, and weaker within the cation-enriched dripzones of adjacent Populus trees. We also found that the NMDS1-gradient for each vegetation layer was strongly correlated with base cations (and inversely with Mn) in canopy throughfall, as well as with soil and bark pH. We conclude that elemental composition in canopy throughfall forms a functional link between terrestrial and epiphytic vegetation. • Epiphytes in the lower canopy and plants in the rooting zone of Picea were recorded • There was a concordance between community composition for epiphytes and plants • Across canopy settings, a throughfall gradient underlined both vegetation layers • The gradient ranked from Ca, Mg, K-rich Populus dripzones to Mn-rich conifer stands • Throughfall chemistry likely mediated the link between plants and epiphytes

Conservation Values and Actor Networks that Shape the Adams River Salmon Run in Tsútswecw Provincial Park, British Columbia

Sockeye salmon are deemed essential to life by Secwépemc Indigenous communities living near the Adams River in South Central British Columbia (BC). They are also an ecological keystone species and a significant contributor to the BC economy. However, salmon populations are in decline throughout the Pacific Northwest, putting communities, economies and ecosystems at risk. Using Actor-Network Theory (ANT) as a lens, we identify the network of actors connected to the Adams River salmon run, examine actor relationships, and consider the impacts these relations have on sustainable conservation practices. We use a community-based participatory research methodology and interviews to investigate the complexity of stakeholder relationships to wild Pacific salmon in BC. Based on our results, there is strong evidence to suggest that localized approaches to salmon conservation, ones guided by local experience and knowledge, are critical to developing inclusive and effective policies.

Population dynamics of the heather vole (Phenacomys intermedius) in commercial forest landscapes of south-central British Columbia, Canada

Abstract Long-term population dynamics are essentially unknown for the western heather vole (Phenacomys intermedius), a relatively rare microtine species. Our objectives were to provide a description of demographic changes in populations of P. intermedius and determine possible causes of these changes. We analyzed four detailed 12- to 22-year data sets that recorded changes in abundance of P. intermedius in a variety of managed forests in south-central British Columbia, Canada from 1993 to 2018. We evaluated three hypotheses (H) that may help explain population changes: heather voles will (H1) have higher populations in sites with (i) abundant dwarf shrubs or (ii) cover of woody debris; (H2) colonize new clear-cuts as dispersal sinks for young voles; and (H3) be at lower abundance when other Microtus species are present at equal or higher numbers. Populations of P. intermedius occurred commonly at ≤ 1 animal/ha (as a density index). However, in favorable habitats such as some new clear-cuts and in “open” pine stands, P. intermedius occurred at mean annual peak numbers of 5–6/ha (as a density index). There were two relatively high populations of P. intermedius in 1994–1995 and 1998, and possibly again in 2002 in the open pine stands. Mean numbers of lactating females and recruits per year tended to follow the pattern of changes in abundance. High populations of P. intermedius occurred in stands with abundant dwarf shrubs in open pine stands but not those with a cover of woody debris structures in clear-cuts, H1, therefore, was only partially supported. A relatively higher proportion of adult than juvenile heather voles on clear-cuts did not support H2: that these harvested sites would be dispersal sinks for young voles. Mean annual numbers of P. intermedius were positively correlated with those of M. longicaudus, at least on clear-cut sites, hence H3 was not supported. Phenacomys intermedius was essentially absent from our closed-canopy mature/old-growth forests but occurred in many managed forest habitats at low abundance (density index of ≤ 1/ha). In early successional habitats after clear-cutting and in open young pine stands this species occurred at moderate abundance and generally appeared stable in numbers across these forest landscapes.