2017

Permanent URI for this collectionhttps://hdl.handle.net/1807/75477

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Arctic science education using public museum collections from the University of Alaska Museum: An evolving and expanding landscape
(Canadian Science Publishing, 2017-07-14) Anderson, Katherine L.; Kaden, Ute; Druckenmiller, Patrick S.; Fowell, Sarah; Spangler, Mark A.; Huettmann, Falk; Ickert-Bond, Stefanie M.
Alaska faces unique challenges in STEM (science, technology, engineering and mathematics) education, including limited accessibility to resources and learning opportunities, and a lack of place-based education resources. Museum education programs, traditionally focused on public outreach through docent-led tours, are playing an increasingly important role in both formal and informal aspects of STEM education to help address these challenges. The University of Alaska Museum (UAM) stands as a model in the Arctic region exemplifying how public natural history museum collections can be utilized to create active place-based learning experiences with the aim of increasing engagement in STEM literacy, and building connections between museums and communities. These efforts take many forms, including the development of teaching materials involving physical objects and/or online data from the open-access database ARCTOS, training pre-service teachers, and implementing citizen science projects. Because many UAM specimens and objects are from Alaska, they are easily incorporated into place-based education, thereby demonstrating how the Arctic environment is unique at local and regional scales. Here, we showcase several programs that are either unique to UAM, or part of larger national projects, and include exemplar teaching modules in order to provide learning opportunities in the Arctic region and other rural settings.
Worth a Thousand Words: Visual Collections and a Long View of the North
(Canadian Science Publishing, 2017-05-24) Kamerling, Leonard
Historical film and media collections in the North contain an essential, indelible message for the future - that cultural knowledge is perishable and impermanent. Throughout the world as bearers of traditional culture pass away, much of their knowledge is lost. Film and audio collections can play a critical role in preserving living knowledge, allowing us to observe, experience, and study singular, irreproducible moments of a culture’s past. As time passes, these unique recorded moments take on a vital function; they become new conduits of knowledge, a visual and aural stand-in for real experience. This paper discusses the role of museum film and audio collections in preserving cultural knowledge and the challenges of extending this resource to the classrooms of remote communities throughout the North. The paper also discusses the collaborative cultural filmmaking initiative of Sarah Elder and Leonard Kamerling, their work with partner Alaska Native communities over a period of two decades, and their setbacks and successes in producing “authentic” records of Alaska Native life in the 1970’s and 80’s, records that are now part of the Alaska Documentary Collections at the University of Alaska Museum of the North.
Modelling impacts of recent warming on seasonal carbon exchange in higher latitudes of North America
(Canadian Science Publishing, 2017-12-22) Mekonnen, Zelalem A.; Grant, Robert F.; Schwalm , Christopher
An ecosystem model, ecosys, has been used to examine the effects of recent warming on carbon exchange in higher latitudes of North America. Model results indicated that gradual warming during the past 30 years has increased net ecosystem productivity (NEP) and leaf area index (LAI). Spring increases in LAI advanced by 2.3 days decade-1 and decreases in autumn were delayed by 5.0 days decade-1 from 1982 to 2006. These advances and delays were corroborated by similar trends observed in the Normalized Difference Vegetation Index. NEP modelled during this period increased at an average rate of 17.6 Tg C decade-1. Increasing carbon losses modelled with soil warming in autumn, when thaw depth was greatest, offset 34% of increasing carbon gains modelled in spring. If autumn warming continues, carbon losses in this season may further offset enhanced carbon sequestration in spring.
On Open Access, data mining and plant conservation in the Circumpolar North with an online data example of the Herbarium, University of Alaska Museum of the North
(Canadian Science Publishing, 2017-11-08) Huettmann, Falk; Ickert-Bond, Stefanie M.
With the advent of global online data sharing initiatives, few limits remain to using the treasure troves of museum data for biodiversity and conservation. The University of Alaska herbarium (ALA) is fully online with metadata. Over 260,000 specimens representing the largest collection of Alaska plants anywhere can be data mined. We found that most specimens were collected through the National Park Serviceâ s Inventory and Monitoring program at Denali National Park and Preserve. The majority of specimens were collected along roads, trails, coastline or waterways, while high-altitude, remote and pristine sampling locations are underrepresented still. Actual field efforts varied over the years, peaking in the late 1980s. From 1-400 specimens were collected per sampling location, and on average 40 species were obtained per collection event at a unique location. Our analysis presents a first data mining inventory of such open access data allowing for a rapid assessment, quality control and predictive modeling involving automated high-performing machine learning algorithms and mapping analysis using open geographic information systems (GIS) concepts. Our research sets a first template for more investigations in the Arctic and we briefly compare with selected specimen details from adjacent landscapes like the Russian Far East, Canada, and the circumpolar North.
Seasonal patterns in acoustic detections of marine mammals near Sachs Harbour, Northwest Territories
(Canadian Science Publishing, 2017-10-10) Halliday, William D.; Insley, Stephen J.; de Jong, Tyler; Mouy, Xavier
The Arctic is changing rapidly, leading to changes in habitat availability and increased anthropogenic disturbance. Information on the distribution of animals is needed as these changes occur. We examine seasonal presence of marine mammals in the western Canadian Arctic near Sachs Harbour, Northwest Territories, using passive acoustic monitoring between 2015 and 2016. We also examined the influence of environmental variables (ice concentration and distance, wind speed) on presence of these species. Both bowhead and beluga whales arrived in late April, and belugas departed in mid-August, while bowheads departed in late-October. Bearded seals vocalizations began in October, peaked from April through June, and stopped in early July. Ringed seals vocalized occasionally in all months, but were generally quiet. Whales migrated in as the ice broke up, and migrated out before ice formed in the autumn. Bearded seals started vocalizing as ice formed, and stopped once ice was almost gone. Given the importance of sea ice to the timing of migration of whales and vocalization by bearded seals, the trends that we present here may change in the future due to the increasing ice-free season caused by climate change. Our study therefore serves as a baseline with which to monitor future change.
Inuvialuit Traditional Ecological Knowledge of Beluga Whale (Delphinapterus leucas) Under Changing Climatic Conditions in Tuktoyaktuk, NT
(Canadian Science Publishing, 2017-11-27) Waugh, Devin; Pearce, Tristan; Ostertag, Sonja K.; Pokiak, Verna; Collings, Peter; Loseto, Lisa L.
This paper documents Inuvialuit TEK of beluga, including ecology and behaviour, hunting techniques, and food preparation under changing climatic conditions in Tuktoyaktuk, NT. Beluga Whale (Delphinapterus leucas) are an important food source for Inuvialuit in the western Canadian Arctic, a region that is experiencing dramatic climate change. Data were collected using semi-directed interviews with 17 Inuvialuit beluga harvesters and participant observation. The research found that Inuvialuit beluga harvesters possess detailed rational knowledge of beluga, particularly regarding hunting techniques and food preparation, both which are guided by a moral code about how to behave with respect to beluga. In terms of beluga ecology and behavior, Inuvialuit knowledge is limited to anecdotal reasoning drawing on generalized observations of beluga and the accounts of others. Inuvialuit are experiencing the effects of climate change, but seem to be coping thus far in the context of beluga harvesting but ongoing change in the region may increase risks associated with hunting and preparing beluga in the future.
Alphaherpesvirus: Isolation, Identification, Partial Characterisation, Associated Pathologic Findings and Epidemiology in Beluga Whales (Delphinapterus leucas) in Alaska and Arctic Canada
(Canadian Science Publishing, 2017-11-20) Nielsen, Ole; Burek-Huntington, Kathleen A.; Loseto, Lisa L.; Morell, Maria; Romero, Carlos H.
Live, dead stranded, and harvested beluga (Delphinapterus leucas) in Alaska and the western Canadian Arctic were screened for viruses utilizing a primary beluga cell line. Samples consisted of swabs from blowhole, anus, and genital tract. Virus cytopathic effect was seen after incubation 6-30 days post infection, and virus-like particles consistent with herpesvirus were observed upon electron microscopy. DNA extraction, cetacean-specific polymerase chain reaction amplification and sequencing of the DNA-dependent DNA polymerase gene fragments of approximately 700 nucleotides revealed the presence of a new species of alphaherpesvirus. Culture positive isolates were recovered from all swab types, from 2001 to 2016. PCR testing of swab and skin lesions from Bristol Bay, Alaska belugas revealed that the herpesvirus was present in the blowholes of a high proportion of the animals. Results suggest that belugas from Canadian and Alaskan locations are infected with alphaherpesvirus. Eight culture positive belugas were identified from Alaska, all but one were adults and all had evidence of skin disease. No Canadian belugas showed signs of skin disease. Virus was isolated from three separate populations indicating it is likely enzootic in belugas. This is the first report of an alphaherpesvirus isolated and propagated from a monodontid species.
Cortisol levels in beluga whales (Delphinapterus leucas): Setting a benchmark for Marine Protected Area monitoring
(Canadian Science Publishing, 2017-11-03) Loseto, Lisa L.; Pleskach, Kerri; Hoover, Carie; Tomy, Gregg T.; Desforges, Jean-Pierre; Halldorson, Thor; Ross, Peter S.
Beluga whales (Delphinapterus leucas) are facing profound changes in their habitat, with impacts expected at the individual and population level. Detecting and monitoring exposure and response to environmental stressors is necessary for beluga conservation and management of human activities. Cortisol has proven a useful tool to assess stress on wildlife. Cortisol was measured in three blubber layers and plasma in subsistence hunted beluga whales from the summers of 2007 to 2010 using an HPLC/MS/MS. We assessed the effect of biological and biochemical factors. Cortisol ranged from ND to 17.8 ng/g in blubber and 2.5 to 61.2 ng/mL in plasma. Concentrations were highest in the inner blubber layer likely reflecting circulating levels. All tissues were significantly higher in 2008 for reasons that remain unclear. Cortisol levels were on par with resting levels in captive belugas. Best fit models for cortisol revealed age to be an important determinant along with length and blubber thickness. Lack of relationships with biochemical factors such as organic contaminants suggest current cortisol levels are not significantly influenced by present contaminant concentrations. Our findings support the use of middle and outer blubber tissues for an integrated measure of chronic stress that are less subject to the influence of acute stress.
Seasonal patterns of soil nitrogen availability in moist acidic tundra
(Canadian Science Publishing, 2017-10-10) McLaren, Jennie R.; Darrouzet-Nardi, Anthony; Weintraub, Michael N.; Gough, Laura
Our ability to predict effects of changing soil nitrogen (N) in Arctic tundra has been limited by our poor understanding of the intra-annual variability of soil N in this strongly seasonal ecosystem. Studies have shown microbial biomass declines in spring accompanied by peaks in inorganic nutrients. However, subsequent to this early pulse, there are few high temporal resolution measurements during the growing season. We hypothesized that: (1) low N would be maintained throughout the growing season; (2) peaks of total free primary amines (TFPA), ammonium (NH4+), and nitrate (NO3-) would follow a sequential pattern driven by mineralization and nitrification; (3) a peak in soil N would occur as plants senesce. We conducted weekly measurements of TFPA, NH4+ and NO3- in two tundra sites, from soil thaw in spring to freeze in fall. At each site, NH4+ peaks were followed by smaller peaks in NO3-, supporting the hypothesis that excess NH4+ would be nitrified. Furthermore, peaks in NH4+ were observed both shortly after leaf expansion and also at plant senescence. The variation in timing between sites and the peaks in NH4+ subsequent to thaw indicate that nutrient limitation in these ecosystems is more dynamic and spatially variable than previously thought.
Ice wedge degradation and CO2 and CH4 emissions in the Tuktoyaktuk Coastlands, NT
(Canadian Science Publishing, 2017-09-26) Martin, Abra F.; Lantz, Trevor C.; Humphreys, Elyn R.
Increases in ground temperature make soil organic carbon in permafrost environments highly vulnerable to release to the atmosphere. High-centred polygonal terrain is a form of patterned ground that may include areas that act as large sources of carbon to the atmosphere because thawing ice-wedges can result in increased ground temperatures, soil moisture and thaw depth. To evaluate the effect of ice wedge degradation on carbon flux, carbon emissions were characterized at two polygonal peatlands in the Tuktoyaktuk Coastlands in northern Canada. Opaque chambers were used to measure CO2 and CH4 emissions from nine non-degraded polygon centres and nine moderately-degraded troughs four times during the growing season. To measure emissions from 10 ponds resulting from severe ice wedge degradation, wind diffusion models were used to characterize fluxes using CO2 and CH4 measurements made in each pond. Our field data show that degraded troughs had increased ground temperature, deeper active layers, and increased CO2 and CH4 emissions. Our study shows that rates of CO2 and CH4 emissions from high-centered polygonal terrain are likely to increase with more widespread melt pond formation in this terrain type.
“We Don't Know anything about Whales:” Ecological Knowledge and Ways of Knowing in Ulukhaktok, NT, Canada
(Canadian Science Publishing, 2017-10-30) Collings, Peter; Pearce, Tristan; Kann, Joseph
This paper reports on interviews conducted during June and July, 2015, to document ecological knowledge of beluga whales in Ulukhaktok, NT. Beluga whales are not a traditionally available or important species for Ulukhaktomiut, but they have appeared in increasing numbers in the waters around the community, and hunters have actively pursed and taken them. We conducted interviews in English with 31 Inuit about their beluga knowledge. A Key Words in Context (KWIC) analysis of the word “know” in the narratives reveals different conceptions of what it means to know something about whales. “Know” variously references practical skill, concern and empathy for others, or the developing awareness of one’s place in the world. Each of these meanings is coded uniquely in Inuinnaqtun, providing insights about the important differences between researchers and Inuit in how “ecological knowledge” is understood and activated.
Description of Cochlear Morphology and Hair Cell Variation in the Beluga Whale
(Canadian Science Publishing, 2017-09-27) Girdlestone, Cassandra D.; Piscitelli-Doshkov, Marina A.; Ostertag, Sonja K.; Morell, Maria; Shadwick, Robert E.
Environmental change and decreased ice cover in the Arctic make new areas accessible to humans and animals. It is important to understand how these changes impact marine mammals, such as beluga whales (Delphinapterus leucas Pallas, 1776). Hearing is crucial in the daily lives of cetaceans. Consequently, we need normal baselines to further understand how anthropogenic noise affects these animals. Relatively little is known about the inner ear morphology of belugas, particularly the organ of Corti, or hearing organ, found within the cochlea. The base of the cochlea encodes for high frequency sounds, while low frequencies are detected in the apex. We showed differences between the apex, or centremost point of the cochlea, and the base, the region closest to the stapes. Our results showed that average outer hair cell density changed from 148 cells/mm in the apex to 117 cells/mm in the base. Cell width varied between the two regions, from 5.8 Âľm in the apex to 8.4 Âľm in the base. These results revealed variation throughout the cochlea, and thus the need to understand the basic morphology, to give further insight on hearing function in belugas, and allow us to recognize damage if or when we find it.
Life in the fast lane: learning from the rare multi-year recaptures of brown lemmings in the High Arctic
(Canadian Science Publishing, 2017-12-20) Fauteux, Dominique; Gauthier, Gilles; Slevan-Tremblay, Guillaume; Berteaux, Dominique
Inter-annual recaptures of Arctic lemmings are extremely rare because their life expectancy is very short, typically less than one year. On Bylot Island, Nunavut, Canada, we live-trapped in summer, marked and released brown lemmings (Lemmus trimucronatus Kerr 1792) between 2004 and 2016 and we performed a large-scale, Before-After Control-Impact experiment from 2014 to 2016 to study effects of predator reduction on their population dynamics. Although inter-annual recaptures of marked lemmings were rare, our long-term study and predator reduction allowed us to capture 21 (1.4%; n = 1523) individuals over two consecutive years and one over three consecutive years. The inter-annual recapture rate was much higher in the predator-reduction grid (5.7%, n = 193) than in the other grids (0.7%, n = 425) during the experiment. Average distance moved between inter-annual recaptures was small (74 m). Our data thus demonstrate that lemmings are physiologically capable of living up to 24 months in the High Arctic, that predation is a major factor affecting lemming survival, including over winter, and that they show high site fidelity among years.
Validation of Oil Spill Transport and Fate Modeling in Arctic Ice
(Canadian Science Publishing, 2017-09-01) French-McCay, Deborah P; Tajalli-Bakhsh, Tayebeh; Jayko, Kathy; Spaulding, Malcolm L; Li, Zhengkai
Reliability of oil spill modeling in Arctic waters for response planning and risk assessments depends on the accuracy of winds, currents, and ice data (cover and drift) used as input. We compared predicted transport in ice, using ice and ocean model results as input, with observed drifter trajectories in the Beaufort Sea and an experimental oil release in the Barents Sea. The ice models varied in ice rheology algorithms used (i.e., Elastic-Viscous-Plastic [EVP], presently used in climate models, versus a new Elasto-Brittle [EB] approach in pack ice) and the time averaging of their outputs, which were provided as input to oil spill models. Evaluations of model performance (skill) against drifters showed improvement using EB instead of EVP rheology. However, model skill was degraded by time-averaging of ocean and ice model vectors before input to the oil spill model. While the accuracy of individual oil model trajectories projected weeks to months into the future is expected to be low, in the event of a spill, forecasts could be updated frequently with satellite and other observations to improve reliability. Comparisons of modeled trajectories with drifters verified that use of the ice-ocean models for ensemble modeling as part of risk assessments is reliable.
Broadening the sea-ice forecaster toolbox with community observations: A case study from the northern Bering Sea
(Canadian Science Publishing, 2017-08-14) Deemer, Gregory J.; Bhatt, Uma S.; Eicken, Hajo; Posey, Pamela G.; Hutchings, Jennifer K; Nelson, James; Heim, Rebecca; Allard, Richard A.; Wiggins, Helen; Creek, Kristina
Impacts of a warming climate are amplified in the Arctic. One notorious impact is recent and record-breaking summertime sea-ice loss. Expanding areas of open water and a prolonged ice-free season create opportunity for some industries, but challenge indigenous peoples relying on sea ice for transportation and access to food. The observed and projected increase of Arctic maritime activity requires accurate sea-ice forecasts to protect life, environment, and property. Motivated by emerging prediction needs on the operational timescale (â ¤ 10 days), this study explores where local indigenous knowledge (LIK) fits into the forecaster toolbox and how it can be woven into useful sea-ice information products. The 2011 spring ice retreat season in the Bering Sea is presented as a forecasting case study. LIK, housed in a database of community-based ice and weather logs, and an ice-ocean forecast model developed by the U.S. Navy are analyzed for their ability to provide information relevant to stakeholder needs. Additionally, metrics for verifying numerical sea-ice forecasts on multiple scales are derived. The model exhibits skill relative to persistence and climatology on the regional scale. At the community scale, we discuss how LIK and new model guidance can enhance public sea-ice information resources.
Hyperpycnal flows control the persistence and flushing of hypoxic high conductivity bottom water in a High Arctic lake
(Canadian Science Publishing, 2017-08-04) Lewis, Ted; Lamoureux, Scott F.; Normandeau, Alexandre; Dugan, Hilary A
In the deepest portions of many lakes, zones of high conductivity bottom water (HCBW) depleted in dissolved oxygen (DO) are present. HCBW and DO are important for determining benthic diversity and abundance, nutrients and contaminant cycling, and understanding the long-term evolution of lakes. We investigate the persistence and removal of HCBW and DO replenishment in a High Arctic lake using physical properties and flow velocity data, along with hydrometric and suspended sediment inflow data over a four-year monitoring period (2007-2010). HCBW was removed in 2007 and 2008, but largely remained in 2009 and 2010. Catchment disturbances in 2007 increased suspended sediment concentrations (SSC) in the inflowing river in 2007 and 2008. In the later two years of monitoring (2009-2010), fluvial sediment availability relaxed to pre-disturbance levels. High SSC in 2007 and 2008 caused by landscape disturbances formed sustained river-generated hyperpycnal flows during the snowmelt period that are linked to HCBW removal. In 2009 and 2010, inflowing river water was periodically denser than lake water; however, HCBW were not removed in these years. Hyperpycnal flows were likely either of insufficient strength or duration, deposited on the delta front, or followed paths that led away from the deepest portion of the lake. (WORD COUNT EXCEEDED)
New records from Banks Island expand the diversity of Eocene fishes from Canada’s western Arctic Greenhouse
(Canadian Science Publishing, 2017-05-29) Gottfried, Michael D.; Eberle, Jaelyn J
Eocene vertebrates from the Canadian Arctic, including sharks, bony fishes, turtles, crocodylians, birds, and mammals, have provided strong evidence for relatively warm ice-free conditions in the Arctic during the Eocene Greenhouse interval. Recent expeditions to Banks Island (NWT) in the western Arctic have recovered a relatively more marine-influenced Eocene fauna, including Sand-tiger sharks, bony fishes, turtle shell fragments, and a single crocodylian specimen. We report here on new additions to this fauna, including diagnostic large scales that confirm the presence of Amia in the western Arctic. One very large lateral line scale corresponds to a fish ca. 1.4 meters in total length, larger than the maximum size for extant Amia calva. We also recovered ca. 100 distinctive teeth that we assign to the teleost genus Eutrichiurides, which is otherwise known from lower latitude Paleogene sites in the USA, India, Africa, and Europe. The genus is interpreted as an ambush predator in shallow marine environments, consistent with the inferred Eocene paleoenvironment of Banks Island. The presence of Eutrichiurides in the Arctic adds a distinctive new element to the Eocene Greenhouse fauna and is intriguing with respect to the biogeography and dispersal capabilities of this taxon.
Diurnal and seasonal variations of tundra CO2 emissions in a polygonal peatland near Salluit, Nunavik, Canada
(Canadian Science Publishing, 2017-06-26) Gagnon, Samuel; Allard, Michel; Nicosia, Aurélien
Polygonal peatlands are carbon-rich permafrost ecosystems that will likely be significantly affected by climate change. However, studies are often constrained to one measurement per day, which impedes assessments of the temporal variability in carbon fluxes. For this reason, we measured ecosystem respiration (ER) of CO2 in a polygonal peatland underlain by continuous permafrost over an entire growing season to determine the effects of temperature and water table depth on the temporal variability of ER. We used four automated closed chambers to measure ER under varying temperature and soil moisture regimes. Temporal variability was approximately the same for the four plots, both on a diurnal and seasonal scale. Both diurnal and seasonal variations in ER were strongly controlled by changes in soil surface temperature. Fluctuations of the water table depth associated with important rainfall events was also an important factor affecting ER on the seasonal scale. We found that water table level fluctuations below 20-25 cm did not significantly affect ER and that most soil respiration took place in the top 10 cm, likely in the surface 2 cm. Our results highlight the importance of monitoring future changes in tundra hydrology, which will determine the depth of organic matter available for aerobic decomposition.
High Incidence and Correlates of Dioecy in the Flora of the Canadian Arctic Archipelago
(Canadian Science Publishing, 2017-05-02) Kevan, Peter G.; Godglick, Becky
In comparing the incidence of dioecy in North American floras, we report a strong, positive correlation with increasing latitude. Dioecy in the High Arctic is highly correlated with woodiness, as elsewhere. It is significantly correlated with fleshy, zoochorous, fruits, as well documented elsewhere. Correlation with floral inconspicuousness, which we define in terms of attractiveness to pollinators (i.e. functionality to pollination), is weak and statistically insignificant. Published findings on that correlation are equivocal; different authors variously defined inconspicuousness in ways that may or may not reflect functionality in pollination. Although we acknowledge that for some diverse taxa (e.g. Salix spp.) the relative importances of anemophily, zoophily (entomophily) and ambophily are unknown, we assigned species to a) anemophily if evidence for entomophily could not be invoked and b) entomophily if insect pollination was considered possible (i.e. counts for entomophily include possibly ambophilous species). We found no correlation between dioecy and anemophily/entomophily The view that insularity favours establishment of dioecious taxa may be invoked by considering localized and disjoint post glacial colonization. The view that dioecy, as a form of xenogamy, has evolved in response to offsetting the adverse consequences of inbreeding and accumulation of mutations may apply under High Arctic conditions further eroding ideas that short, harsh, active seasons promote self-fertilization (autogamy), agamospermy, and vegetative reproduction while disfavouring xenogamy by insect or wind pollination.
Estimating age of rock cairns in southeast Alaska by combining evidence from successional metrics, lichenometry, and carbon dating
(Canadian Science Publishing, 2017-05-08) McCune, Bruce; Ali, Nijmah; Hartley, Ralph; Hunt, William
We estimated ages of rock cairns in alpine tundra in southeast Alaska by combining information from three general classes of methods, each of them imperfect, but considered together providing better estimates than any of the three alone. We used lichenometry, radiocarbon dating, and five successional metrics: score on a nonmetric multidimensional scaling axis of vegetation composition, cover-weighted average successional class of organisms, overgrowth of contact points between rocks, sum of species cover, and species richness. Lichenometry estimated absolute ages, but with considerable error because we violated key assumptions. Successional metrics provided relative ages, probably with more precision than lichenometry, but did not provide absolute ages. Although the relative age estimates from traditional lichenometry seemed least reliable, collectively they supported the hypothesis of prehistoric origins for the cairns with a range of possible absolute ages of 258-892 yr. Similarly, radiocarbon dates for the cairns suggested cairn construction before European settlement, about 450 to 1500 ybp. The five successional metrics were in general agreement with each other on relative ages. Combining all methods provided more information than any of the methods alone. We conclude that the cairns were built over a range of times, probably over centuries, most likely 500-1500 ybp.

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