2016

Permanent URI for this collectionhttps://hdl.handle.net/1807/71209

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The Chic-Choc Mountains are the last southern refuge for Arctic lichens in eastern North America
(Canadian Science Publishing, 2016-07-21) McMullin, Richard Troy; Dorin, Briann
Endemic and disjunct populations of vascular plants and cryptogams occurring in the Chic-Choc Mountains on the GaspĂŠ Peninsula in eastern QuĂŠbec, Canada have been attracting botanists for over a century. Though controversial, these ancient mountains have been hypothesized to have been nunataks during the Wisconsin glaciation in-part because they contain vascular plants that are not known to colonize nearby mountains with similar environments that were not thought to be nunataks. To determine whether there are lichen species that have the same pattern as the vascular plants we examined the North American distribution of all the ca. 600 lichens known from the Chic-Chocs. Fifteen Arctic-alpine species were found to reach the edge of their southeastern North American range in the Chic-Chocs. Six of these species are not known to occur again for over 1000 km to the north. These results provide an additional layer of biogeographic knowledge about the unusual flora of the Chic-Chocs and lend some support to the hypothesis that the Chic-Chocs might have been nunataks during the last glacial period. Any Arctic-alpine species occurring in the Chic-Chocs are good candidates for monitoring the effects of climate change, but the 15 lichen species that reach their southeastern limit in this range might be the most vulnerable.
Comparison of Carbon and Nitrogen Storage in Mineral Soils of Graminoid and Shrub Tundra Sites, Western Greenland
(Canadian Science Publishing, 2016-10-21) Petrenko, Chelsea; Bradley-Cook, Julia; Lacroix, Emily; Friedland, Andrew; Virginia, Ross
Shrub species are expanding across the Arctic in response to climate change and biotic interactions. Changes in belowground carbon (C) and nitrogen (N) storage are of global importance because Arctic soils store approximately half of global soil C. We collected ten (60 cm) soil cores each from graminoid- and shrub-dominated soils in western Greenland and determined soil texture, pH, C and N pools, and C:N ratios by depth for the mineral soil. To investigate the relative chemical stability of soil C between vegetation types, we employed a novel sequential extraction method for measuring organo-mineral C pools of increasing bond-strength. We found that: (i) mineral soil C and N storage was significantly greater under graminoids than shrubs (29.0 ± 1.8 versus 22.5 ± 3.0 kg C m-2 and 1.9 ± .12 versus 1.4 ± 1.9 kg N m-2); (ii) chemical mechanisms of C storage in the organo-mineral soil fraction did not differ between graminoid and shrub soils; and (iii) weak adsorption to mineral surfaces accounted for 40-60% of C storage in organo-mineral fractions— a pool that is relatively sensitive to environmental disturbance. Differences in these C pools suggest that rates of C accumulation and retention differ by vegetation type, which could have implications for predicting future soil C pool storage.
Biodiversity Databases in Russia: Towards a National Portal
(Canadian Science Publishing, 2016-12-10) Ivanova, Natalya Vladimirovna; Shashkov, Maxim Petrovich
Russia holds massive biodiversity data accumulated in botanical and zoological collections, literature publications, annual reports of natural reserves, nature conservation and monitoring study project reports. While some data has been digitized and organized in databases or spreadsheets, most of the biodiversity data in Russian remains dormant and digitally inaccessible. Concepts of open research data is spreading, the lack of data publishing tradition and of use of data standards remain prominent. The majority of Russian biodiversity databases does not have web interfaces, and are accessible only to a limited numbers of researchers. A few information systems have interactive maps with the species occurrence data and systems allowing registered users to upload data. Despite the complexity and size of the biodiversity data landscape in Russia, the interest in publishing data through international biodiversity portals is increasing among Russian researchers. Since 2014, institutional data publishers in Russia have published about 130 000 species occurrences through GBIF.org. The increase in data publishing activity calls for creation a GBIF node in Russia, aiming to support Russian biodiversity experts in international data work.
Arctic Museum Collections--Special Issue The Beringian Coevolution Project: Holistic Collections of Mammals and Associated Parasites Reveal Novel Perspectives on Evolutionary and Environmental Change in the North
(Canadian Science Publishing, 2016-12-23) Cook, Joseph; Galbreath, Kurt; Bell, Kayce; Campbell, Mariel; Carrière, Suzanne; Colella, Jocelyn P; Dawson, Natalie G; Dunnum, Jonathan L; Eckerlin, Ralph P; Greiman, Stephen E; Fedorov, Vadim; Haas, Genevieve M. S.; Haukisalmi, Voitto; Henttonen, Heikki; Hope, Andrew G; Jackson, Donavan; Jung, Tom; Koehler, Anson V; Kinsella, John M; Kresja, Dianna; Kutz, Susan J; Liphardt, Schuyler; MacDonald, Stephen O; Malaney, Jason L; Makarikov, Arseny; Martin, Jon; McLean, Bryan S; Mulders, Robert; Nyamsuren, Batsaikhan; Talbot, Sandra L; Tkach, Vasyl; Tsvetkova, Albina; Toman, Heather; Waltari, Eric C; Whitman, Jackson S; Hoberg, Eric P
The Beringian Coevolution Project (BCP), a field program underway in the high northern latitudes since 1999, has focused on building key scientific infrastructure for integrated specimen-based studies on mammals and their associated parasites. BCP has contributed new insights across temporal and spatial scales into how ancient climate and environmental change have shaped faunas, emphasizing processes of assembly, persistence, and diversification across the vast Beringian region. BCP collections also represent baseline records of biotic diversity from across the northern high latitudes at a time of accelerated environmental change. These specimens and associated data form an unmatched resource for identifying hidden diversity, interpreting past responses to climate oscillations, documenting contemporary conditions, and anticipating outcomes for complex biological systems in a regime of ecological perturbation. Because of its dual focus on hosts and parasites, the BCP record also provides a foundation for comparative analyses that can document the effects of dynamic change on the geographic distribution, transmission dynamics, and emergence of pathogens. By using specific examples from carnivores, shrews, lagomorphs, rodents and their associated parasites, we demonstrate how broad, integrated field collections provide permanent infrastructure that informs policy decisions regarding human impact and the effect of climate change on natural populations.
A synthesis of thermokarst lake water balance in high-latitude regions of North America from isotope tracers
(Canadian Science Publishing, 2016-11-03) MacDonald, Lauren Ashley; Wolfe, Brent B.; Turner, Kevin W.; Anderson, Lesleigh; Arp, Christopher D.; Birks, S. Jean; Bouchard, Frédéric; Edwards, Thomas W.D.; Farquharson, Nicole; Hall, Roland I.; McDonald, Ian; Narancic, Biljana; Ouimet, Chantal; Pienitz, Reinhard; Tondu, Jana; White, Hilary
Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion to drainage and evaporative desiccation. Here, we provide a synthesis of hydrological conditions for 376 lakes of mainly thermokarst origin across high-latitude North America. We assemble surface-water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska), Yukon Flats (Alaska), Old Crow Flats (Yukon), northwestern Hudson Bay Lowlands (Manitoba) and Nunavik (QuĂŠbec). These landscapes represent the broad range of thermokarst environments by spanning gradients in meteorological, permafrost and vegetation conditions. An isotope framework was established based on flux-weighted long-term averages of meteorological conditions for each lake to quantify water-balance metrics. The isotope composition of source water and evaporation-to-inflow ratio for each lake was determined, and results demonstrated a substantial array of regional and sub-regional diversity of lake hydrological conditions. Controls on lake water balance and how these vary among the five landscapes and with differing environmental drivers are assessed. Findings reveal that lakes in the Hudson Bay Lowlands are most vulnerable to evaporative desiccation, whereas those in Nunavik are most resilient. However, we also identify the complexity in predicting hydrological responses of these thermokarst landscapes to future climate change.
Multi-year impacts of permafrost disturbance and thermal perturbation on High Arctic stream chemistry
(Canadian Science Publishing, 2016-12-02) Lamhonwah, Daniel; Lafrenière, Melissa J.; Lamoureux, Scott; Wolfe, Brent B.
Permafrost disturbances (such as active layer detachment (ALD) slides) and thermal perturbation (deep ground thaw from high soil temperatures) alters Arctic surface water chemistry. However, the potential multi-year impacts on water chemistry and the ultimate recovery time are not well understood. This study evaluates the impacts and recovery following disturbance of a High Arctic catchment in 2007 from ALDs. We measured ion concentrations and stable isotopes in surface waters collected between 2006 and 2014 from paired catchments - one disturbed and the other not. 2007 and 2012 were exceptionally warm and represent unusual thermal perturbation for both catchments. Results indicate that the exposure and mobilization of soluble ions in near surface soil is a key control over dissolved ion concentrations and composition following ALDs. Runoff in the disturbed catchment shows increased total dissolved solute (TDS) concentrations and seasonal TDS fluxes, and changes to the composition of individual ions. These impacts persist seven years after disturbance, and are consistent with the thawing of the solute-rich transient layer and upper permafrost. Thermal perturbation increased TDS concentrations and seasonal fluxes in runoff for up to two years as ions released from ground thaw appear to be available for flushing in subsequent summers.
Effects of changing permafrost and snow conditions on tundra wildlife: critical places and times
(Canadian Science Publishing, 2016-12-11) Berteaux, Dominique; Gauthier, Gilles; Domine, Florent; Ims, Rolf Anker; Lamoureux, Scott; Levesque, Esther; Yoccoz, Nigel
The change of water phase around 0째C has considerable impacts on wildlife ecology because liquid and solid water strongly differ in their insulating capability, mechanical resistance, and light reflectance. Freeze and melt events thus have strong ecological relevance, particularly in the Arctic where snow and ice are omnipresent and their conditions are changing due to climate warming. We first review the mechanisms linking water phase transitions to wildlife ecology, with emphasis on seven key processes. These processes are illustrated with examples or detailed case studies, such as snowmelt and icing events affecting herbivore populations, thaw-induced collapse of structures used by wildlife for reproduction, and thermal erosion of ice wedges reducing waterfowl habitat. We infer that water phase transitions generate some critical places and critical times that play a disproportionate role in the ecology of tundra wildlife. We map these critical places and times to help structure future research on the effects of climate change on tundra wildlife, in a context where changing permafrost and snow conditions might trigger abrupt ecological responses in the Arctic tundra.
Paleolimnology of thermokarst lakes: a window into permafrost landscape evolution
(Canadian Science Publishing, 2016-11-18) Bouchard, Frédéric; MacDonald, Lauren Ashley; Turner, Kevin W.; Thienpont, Joshua R.; Medeiros, Andrew Scott; Biskaborn, Boris K.; Korosi, Jennifer; Hall, Roland I.; Pienitz, Reinhard; Wolfe, Brent B.
Widespread across northern permafrost landscapes, thermokarst ponds and lakes provide vital wildlife habitat and play a key role in biogeochemical processes. Stored in the sediments of these typically shallow and dynamic waterbodies are rich sources of paleoenvironmental information whose potential has not yet been fully exploited, likely because of concerns over stratigraphic preservation and challenges to develop reliable sediment core chronologies. Here, we present an overview of recently-derived informative paleolimnological reconstructions based on multi-parameter analysis of sediment archives from permafrost aquatic basins. We include examples from across the Canadian North, Alaska, and Siberia that illustrate their value for providing insights into temporal patterns of lake inception, catchment erosion, aquatic productivity, hydrological evolution, and landscape disturbances. Although not captured in our survey, emerging research directions focused on carbon accumulation, storage, and balance hold much promise for contributing to global climate change science.
Limnological evolution of Zelma Lake, a recently drained thermokarst lake in Old Crow Flats (Yukon, Canada)
(Canadian Science Publishing, 2016-08-04) Tondu, Jana; Turner, Kevin W.; Wiklund, Johan A.; Wolfe, Brent B.; Hall, Roland I.; McDonald, Ian
Evidence from remote sensing studies suggests that the frequency of thermokarst lake drainage events is increasing in response to climate change, but the consequences of these changes on the limnology of remaining waterbodies is unknown. Here, we utilize a multi-parameter paleolimnological record and post-drainage water isotope and chemistry monitoring to characterize the limnological evolution of Zelma Lake, in Old Crow Flats (OCF), Yukon. During the early part of the record (~1678 to 1900 CE), analysis of geochemical parameters and algal pigments indicate relatively stable limnological conditions. Abruptly beginning at ~1900, Zelma Lake experienced a 40-year phase of reduced production likely resulting from thermokarst shoreline expansion and associated increases in turbidity and low light availability. This was followed by ~70 years of increasing production, likely from the stabilization of shorelines combined with a warming climate. Zelma Lake catastrophically drained in June 2007. Post-drainage conditions were characterized by intense eutrophication marked by increases in nutrient and major ion concentrations and the unprecedented occurrence of okenone and diatoxanthin pigments. Comparison to the post-drainage paleolimnological record from another thermokarst lake in OCF indicates sharp increase of production is likely a common outcome of thermokarst lake drainage, yet intensity differs owing to site-specific catchment characteristics
Vulnerability of northern water supply lakes to changing climate and demand
(Canadian Science Publishing, 2016-11-24) Bakaic, Michael; Medeiros, Andrew Scott
Arctic regions face a unique vulnerability to shifts in seasonality, which influences the summer recharge potential of freshwater reservoirs caused by decreased precipitation and increased evaporative stress. This pressure puts small remote northern communities at risk due to limited existing freshwater supply. The lack of baseline knowledge of existing supply, demand, or reservoir recharge potential increases this risk. We therefore address this knowledge gap through a water resource assessment of municipal supply over a 20 year planning horizon in two communities in Arctic Canada using a novel heuristic model and existing data sources. We generated climate and demand scenarios to identify the mechanisms of drawdown, as well as examine the influences on replenishment. We found a pronounced vulnerability to reduced winter precipitation and/or increased ice-thickness of reservoirs. Our heuristic supply forecasts indicate an immediate need for freshwater management strategies for northern communities in Canada.
UAV Photogrammetry for Mapping Vegetation in the Low-Arctic
(Canadian Science Publishing, 2016-06-17) Fraser, Robert; Olthof, Ian; Lantz, Trevor C; Schmitt, Carla
Plot-scale field measurements are necessary to monitor changes to tundra vegetation, which has a small stature and high spatial heterogeneity, while satellite remote sensing can be used to track coarser changes over larger regions. In this study we explored the potential of Unmanned Aerial Vehicle (UAV) photographic surveys to map low-Arctic vegetation at an intermediate scale. A multicopter was used to capture highly overlapping, sub-centimetre photographs over a 2 ha site near Tuktoyaktuk, NWT. Images were processed into ultra-dense 3D point clouds and 1 cm resolution orthomosaics and vegetation height models using Structure-from-Motion (SfM) methods. Shrub vegetation heights measured on the ground were accurately represented using SfM point cloud data (r2 = 0.96, SE = 8 cm, n = 31) and a combination of spectral and height predictor variables yielded an 11-class classification with 82% overall accuracy. Differencing repeat UAV surveys before and after manually trimming shrub patches showed vegetation height decreases in trimmed areas (-6.5 cm, SD = 21 cm ). Based on these findings, we conclude that UAV photogrammetry provides a promising, cost-efficient method for high-resolution mapping and monitoring of tundra vegetation that can be used to bridge the gap between plot and satellite remote sensing measurements.
Influence of Hudson Bay on the Carbon Dynamics of a Hudson Bay Lowlands Coastal Site
(Canadian Science Publishing, 2016-05-18) Delidjakova, Kristina Kirilova; Bello, Richard L; Higuchi, Kaz; Pokharel, Bipin
Eddy Covariance (EC) estimates of Net Ecosystem Exchange (NEE) and the surface energy balance were gathered from an elevated peat plateau within the Hudson Bay Lowlands near Churchill, Manitoba, Canada (58° 43' 46''N, 93° 49' 57''W) during the growing season of 2007. Data were segregated into onshore and offshore wind regimes to assess the advective influence of the generally cold and moist Hudson Bay air masses compared to generally warm and dry air masses of non-marine origin. Monthly average net ecosystem exchange (NEE) ranged from an uptake of 0.2 µmol/m2/s in September to 5.6 µmol/m2/s in July. Over the growing season, onshore winds from Hudson Bay contributed to an average 4.2°C reduction in air temperature and an NEE increase of 27%. When normalized with respect to sunlight receipt, the ratio of gross primary production to photosynthetically active radiation (GPP/PAR) was 26% stronger for offshore regimes than for onshore, while the ratio of ecosystem respiration to PAR (ER/PAR) was 71% stronger for offshore regimes. It was concluded that GPP maintains the same strength for both wind regimes, while ER is significantly stronger for offshore regimes, resulting in reduced NEE capacity during periods when winds originate from inland.
What is the most efficient and effective method for long-term monitoring of alpine tundra vegetation?
(Canadian Science Publishing, 2016-03-23) Mamet, Steven Douglas; Young, Nathan; Chun, Kwok Pan; Johnstone, Jill
Non-destructive estimations of plant community characteristics are essential to vegetation monitoring programs. However, there is no universally accepted method for this purpose in the Arctic, partly because not all programs share the same logistical constraints and monitoring goals. Our aim was to determine the most efficient and effective method for long-term monitoring of alpine tundra vegetation. To achieve this, we established 12 vegetation-monitoring plots on a south-facing slope in the alpine tundra of southern Yukon Territory, Canada. Four observers assessed these plots for vascular plant species abundance employing three methods: visual cover (VC) and subplot frequency (SF) estimation, and modified point-intercept (PI; includes rare species present but not intersected by a pin). SF performed best in terms of time required per plot and sensitivity to variations in species richness. All methods were similarly poor at estimating relative abundance for rare species, but PI and VC were substantially better at high abundances. Differences among methods were larger than among observers. Our results suggest that SF is best when the monitoring focus is on rare species or species richness across extensive areas. However, when the focus is on monitoring changes in relative abundance of common species, VC or PI should be preferred.
Applications of Local Floras for Floristic Subdivision and Monitoring Vascular Plant Diversity in the Russian Arctic
(Canadian Science Publishing, 2016-07-07) Khitun, Olga; Koroleva, Tatiana; Chinenko, Svetlana; Petrovsky, Vladislav; Pospelova, Elena; Pospelov, Igor; Zverev, Andrei
The local flora method has been used by Russian botanists for studying vast wilderness areas. The method strives to determine the total flora within a certain limited area and provides comparable data for spatial comparisons between different locations and temporal comparisons at the same location. Complete vascular plant diversity was sampled in 240 localities with an area between 100-300 km2 each throughout the Russian Arctic. These data were incorporated in a specially developed Integrated Botanical Information System (IBIS). This database provides a unique opportunity to study spatial gradients of different floristic variables. Pair-wise similarity of species composition and proportions of various phytogeographical groups in local floras were used in a floristic subdivision of the Russian Arctic. The floristic units derived by this method often resembled subprovinces of Yurtsev (1994), but there were also several areas of non-alignment. Application of local floras for monitoring of temporal changes has several constraints. However, nine local floras were re-visited 20-70 years after the initial survey. Increases in the number of Boreal and Hypoarctic species were recorded in the southern local floras. Standardized methods and the use of modern technical tools for accurate documentation could enable use of this approach at observatories across the Arctic.
Reactions of ground-nesting marine birds to human disturbance in the Canadian Arctic
(Canadian Science Publishing, 2016-04-16) Mallory, Mark
I studied the reactions of five, ground-nesting marine bird species (Arctic tern Sterna paradisaea; Sabine’s gull Xema sabini; common eider Somateria mollissima; long-tailed duck Clangula hyemalis; Ross’ gull Rhodostethia rosea) breeding in the low and high Arctic to disturbance from nearby aircraft, as well as avian flight initiation response to humans approaching on foot. All species except nesting long-tailed ducks and common eiders departed their nest when overhead aircraft were within 200 m, with loafing birds often flying off when aircraft were still 1 km away. There was considerable individual and species-specific variation in responses to approaching humans, with some nesting birds not flushing from their nest until touched by a researcher (e.g., waterfowl; 0 m), while others flushed when people were 400 m away (Ross’s gull). Excluding Ross’s gulls, 95% of the individuals of most species did not initiate flight until humans were ≤ 100 m from the nest, suggesting that this might represent a minimum, suitable “buffer zone” around nesting colonies for non-motorized human activities.
Trends in body condition in polar bears (Ursus maritimus) from the Southern Hudson Bay subpopulation in relation to changes in sea ice
(Canadian Science Publishing, 2016-02-15) Obbard, Martyn Ernest; Cattet, Marc R.L.; Howe, Eric J.; Middel, Kevin R.; Newton, Erica J.; Kolenosky, George B.; Abraham, Kenneth F.; Greenwood, Craig J.
Sea ice is declining over much of the Arctic. In Hudson Bay the ice melts completely each summer, and advances in break-up have resulted in longer ice-free seasons. Consequently, earlier break-up is implicated in declines in body condition, survival, and abundance of polar bears (Ursus maritimus Phipps, 1774) in the Western Hudson Bay (WH) subpopulation. We hypothesised that similar patterns would be evident in the neighbouring Southern Hudson Bay (SH) subpopulation. We examined trends 1980–2012 in break-up and freeze-up dates within the entire SH management unit and within smaller coastal break-up and freeze-up zones. We examined trends in body condition for 900 bears captured during 1984–1986, 2000–2005, and 2007–2009 and hypothesised that body condition would be correlated with duration of sea ice. The ice-free season in SH increased by about 30 days 1980–2012. Body condition declined in all age and sex classes, but the decline was less for cubs than for other social classes. If trends towards a longer ice-free season continue in the future, further declines in body condition and survival rates are likely, and ultimately declines in abundance will occur in the SH subpopulation.
Characterizing Phosphorus Removal in Passive Waste Stabilization Ponds in Arctic Communities
(Canadian Science Publishing, 2016-02-18) Schmidt, Jordan J; Ragush, Colin M; Krkosek, Wendy H; Gagnon, Graham A; Jamieson, Rob C
A majority of communities in the Canadian territory of Nunavut rely on passive waste stabilization ponds (WSPs) for domestic wastewater treatment. Little research has been conducted on the treatment performance of these systems. Therefore, in response to impending federal wastewater regulations, a research program was conducted in order to characterize contaminant removal, with phosphorus a contaminant of particular concern. The performance of WSPs in the Arctic communities of Kugaaruk, Pond Inlet, Grise Fiord and Clyde River was evaluated from 2011 to 2014. Removal of total phosphorus was highly variable ranging from 24% (Pond Inlet, 2014) to 76% (Grise Fiord, 2011). The average removal efficiency was 44%. Effluent total phosphorus concentrations generally exceeded 7 mg P/L, partly due to elevated raw wastewater concentrations. Over the course of the treatment season (defined as June to September, when the WSP is thawed), limited additional total phosphorus removal was observed. A fractionation analysis of WSP sediments showed that organic phosphorus and phosphorus bound to aluminum and iron were the predominant forms, which provided insight into primary treatment mechanisms. Further studies on these mechanisms are needed in order to optimize Arctic WSP treatment.

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