Search

This research investigates the role air transportation plays in remote community resilience by examining air cargo delivery and flight operations in northern Ontario, Canada. Building off of the Disaster Resilience of Place (DROP) model for community resilience, we develop a high-level interdependency model that shows the interdependencies between community infrastructure systems and air transportation in the unique context of remote communities that rely on air transportation. Air transportation is the only mode of travel available year-round for the 26 remote communities studied. Alternative modes are seasonal (e.g., winter roads) and threatened by climate change. Analysing 6 years of cargo data highlights infrastructure interdependencies in energy, the built environment, and transportation systems. Flight operations data and semi-structured interviews with airline employees advance our understanding of air transportation infrastructure and operating challenges that impact flight reliability and ultimately remote community resilience. [ABSTRACT FROM AUTHOR]

The Matanuska--Susitna Borough is the fastest growing region in the State of Alaska and is impacted by a number of human activities. We conducted a multiscale assessment of the stressors facing the borough by developing and mapping the Index of Watershed Integrity (IWI) and Index of Catchment Integrity (the latter considers stressors in areas surrounding individual stream segments exclusive of upstream areas). The assessment coincided with the borough's stormwater management planning. We adapted the list of anthropogenic stressors used in the original conterminous United States IWI application to reflect the borough's geography, human activity, and data availability. This analysis also represents an early application of the NHDPlus High Resolution geospatial framework and the first use of the framework in an IWI study. We also explored how remediation of one important stressor, culverts, could impact watershed integrity at the catchment and watershed scales. Overall, we found that the integrity scores for the Matanuska--Susitna basin were high compared to the conterminous United States. Low integrity scores did occur in the rapidly developing Wasilla--Palmer core area. We also found that culvert remediation had a larger proportional impact in catchments with fewer stressors. [ABSTRACT FROM AUTHOR]

The northern boreal forest in Ontario, Canada, in the sub-Arctic above the 51st parallel, is the territorial homeland of the Cree, Ojibwe, and Ojicree Nations. These Nations are represented by the political organization Nishnawbe Aski Nation (NAN). January 6–March 31, 2011 the researchers and NAN collaborated in a study to record observations of changes in the forest environment attributed to climate change and share and exchange information and perspectives about climate change. Data were collected from 10 First Nation communities across a geographic area of ∼110,800 km2(43,000 mi2). We explore climate change impacts through the lens of “blue-ice”, a term embedded in their languages across the fieldwork area and reframe adaptation in the First Nations' perspective and worldview. Changes in blue-ice on the landscape are affecting transportation in traditional activities such as hunting and fishing, as well as the delivery of essential community supplies. The word “adaptation” linked to climate change does not exist in their languages and the term is associated with European colonization. We propose the term “continuity” to reflect the First Nation worldview. Our recommendation is giving First Nations' perspectives and knowledge of their territorial landscape a foundational role in the development of climate change policy for Ontario's northern boreal forest. [ABSTRACT FROM AUTHOR]

Traditional Knowledge (TK) is increasingly valued in long-term monitoring of wildlife health, particularly in northern Canada where Chronic Wasting Disease (CWD) may represent a threat to valued caribou and moose populations. This article presents comparative research results (1998–2002 and 2010) about caribou and moose health based on research with Łutsël K’é First Nation, Northwest Territories (Canada). Elders’ knowledge, harvester observations, harvest data and consumption data indicate a decline in the availability of barren ground caribou and range shifts of both caribou and moose during the study period. An anomalous sighting of a white tailed deer near the community, coupled with moderate community concerns about CWD would suggest the need for greater monitoring of wildlife health. As resources for scientific monitoring become limited, the article suggests how northern Indigenous communities can use their own knowledge (TK) to monitor changes in arctic ecosystems. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous Cantwell Formation in Denali National Park and Preserve (DENA), Alaska, contains an unparalleled fossil avian biodiversity. The Cantwell Formation, thousands of metres thick, was deposited near its current latitude and is exposed throughout much of DENA and elsewhere in the central Alaska Range. The Formation comprises a lower, dominantly fluvial sedimentary unit and an upper, mostly volcanic unit. Sedimentation of the lower unit was mainly in alluvial fan, braided and meandering stream, and lacustrine environments, with possible marginal-marine influence at times. Pollen data suggest that these sedimentary rocks are late Campanian or early Maastrichtian in age; thus the Cantwell Formation is correlative with other well-known dinosaur localities in Alaska. Bird tracks are preserved in multiple locations along a 40-km transect in DENA in fluvial and lacustrine deposits. Some bird tracks are found in association with dinosaur tracks and others are found on beds interbedded with dinosaur track-bearing layers. The approximate body sizes of the birds based on tracks show a range from sparrow- to heron-sized birds (∼25-30% larger than the modern Sandhill Crane Grus canadensis). The Cantwell Formation contains footprints assigned to several ichnotaxa found in either Asia or North America based on such morphological criteria as the presence or absence of a hallux, print size and shape, and angle of divarication: Aquatilavipes swiboldae, Ignotornis mcconnelli, Magnoavipes denaliensis sp. nov., Gruipeda vegrandiunus sp. nov. and Uhangrichnus chuni. The presence of a mixed Asian and North American ichnofauna suggests that at least some birds used Alaska as a bridge between Asia and North America. This diverse assemblage of avian traces, combined with the known fossil bone record and invertebrate trace fossil record, demonstrates that the northern Late Cretaceous polar region contained significant biodiversity. [ABSTRACT FROM AUTHOR]

We describe a new species of ptychodactiarian sea anemone, Ptychodactis aleutiensis, and redefine the family Ptychodactiidae and the previously monotypic genus Ptychodactis to accommodate P. aleutiensis sp. nov. Individuals of the new species were photographed and collected at depths of less than 20 m off the Aleutian Islands, Alaska. Many were found detached, adrift in the water. The species differs from the only other member in its genus, Ptychodactis patula, in having more tentacles, tentacles only at the margin, frilled structures associated with only two siphonoglyphs, infertile primary mesenteries, oral stomata, holotrichous nematocysts of two size classes in the tentacles, actinopharynx, and mesenterial filaments, and by the morphology of the holotrichs and spirocysts. It is the fourth species of ptychodactiarian described; Ptychodactis is the only genus of suborder Ptychodacteae with more than one species. [ABSTRACT FROM AUTHOR]

Climate change is expected to have a substantial impact on hydrology on both a global and regional scale. Although the anticipated warming is expected to be greatest in the northern regions and cause alteration in the hydrological cycle, it has yet to be resolved, to what extent these hydrological changes will alter such flow characteristics as flow velocity, bed shear stress and stream power in Sub-Arctic rivers. Future changes in the fluvial erosion potential are studied in the Sub-Arctic Tana River, on the border of Finland and Norway. We modelled future discharge scenarios for the years 2070 to 2099 with a conceptual hydrological model incorporating three emission scenarios, with two global and one regional climate model. These simulated flood discharges were used as input hydrographs to model flow characteristics with a two-dimensional hydraulic model. Differences in the spatial distribution of flow characteristics between frequent (HQ1/2a) and infrequent floods (HQ1/250a) were examined. Compared to the present, in most simulations, both HQ1/250a and HQ1/2a flood discharges diminished, with spring floods occurring earlier also. Although the relative reduction in flow characteristics (velocities, bed shear stresses and stream powers per unit area) was more notable in 1/2a compared to 1/250a floods, the discharge peaks of the former would theoretically still be able to transport the fine sediments that form the river bed. Based on most of the climate scenarios, autumnal floods become more frequent in the future and hence, their role in sediment transport may become more significant compared to the present-day situation. [ABSTRACT FROM AUTHOR]

Background: Considerable changes in vegetation structure and distribution are predicted in high latitude ecosystems as a result of amplified climate change. However, some documented plant community changes do not follow model predictions. Aim: We compared the growth of and the responses to climate variation by the thermophilic aspen (Populus tremula) and its sub-Arctic competitor mountain birch (Betula pubescens ssp. czerepanovii) over the past 100 years. Methods: Repeat photography, high-resolution vegetation transects, dendro-ecological analysis, and local climate record archives were used to study changes in vitality and distributional range of the two tree species in response to climate variability. Results: Aspen grew 45% faster and had seven times higher recruitment numbers than birch. However, no aspen stand expansion was observed, most likely because of browsing by moose (Alces alces). Birch, on the other hand, suffered from cyclic outbreaks of the autumnal moth (Epirrita autumnata). One-hundred-year-old birch trees experienced on average 9.0 years of reduced growth due to moth herbivory compared to 1.4 years for aspen. Moreover, these moth outbreaks on birch stimulated recruitment of aspen in birch stands. Conclusions: As the sub-Arctic continues to become warmer, the dynamics between aspen and birch in forest ecosystems will likely depend on the number of vertebrate browsers relative to the number of aspen recruits, while major moth outbreaks on birch may facilitate the spread of aspen by reducing competition. Our results suggest that alternating episodes of apparent species range stabilities (homeostasis) and abrupt non-linear shifts may characterise species migration patterns in this ecosystem. [ABSTRACT FROM AUTHOR]

The mountain permafrost distribution in the Abisko region in northern Sweden has been assessed using a combination of empirical and statistical analysis. The empirical data was obtained using the bottom temperature of snow cover (BTS) method, supported by continuous ground temperature measurements. The statistical analysis was based on 148 data points in total and used logistic regression to model the probability of permafrost occurrence. Further, Geographically Weighted Regression (GWR) was introduced as an exploratory tool for detecting non-stationarity in the relationships between permafrost and the independent variables models and showed to be a useful tool in the statistical analysis. As a result of the GWR analysis the region was divided into two subregions. The models show probabilities >0.8 for permafrost at elevations above 1300 m a.s.l. in the western part of the region. In the eastern part, the probabilities are likely to be influenced by the potential incoming shortwave summer radiation, indicating a probability >0.8 above 850 m a.s.l. on the north-east and east-facing slopes, above 1000 m on the west-facing slopes and above 1100 m a.s.l. on the south-facing slopes. Permafrost conditions throughout the region were found to be marginal and sensitive to current warming trends. [ABSTRACT FROM AUTHOR]

Chlorophyll a, meteorology and hydrography were sampled during a 3 year period in Altafjord and Porsangerfjord. The analysis demonstrated a decoupling between spring bloom progression and the classical 'Sverdrup' regulators, i.e. there was no correlation between spring bloom biomass and critical depth, mixed or station depth and irradiance. The only significant correlation was linear between bloom magnitude and day length. We also observed significant correlations between log chlorophyll a and critical depth, irradiance and heat flux. From early March to mid-May, day length increases from 7 to 24 h in the area, whereas daily integrated irradiance increases ca. 14 times. Then, if blooms have not yet triggered early in April, water turbidity will remain low and critical depth will deepen rapidly, causing blooms to start after this date, i.e. irradiance will become the main forcing function if initial stocks are present. Another characteristic feature in the area is that spring bloom concentrations are low and that production is more spread out throughout the growth season, contrary to what is common further south (spring bloom, summer recession and autumn bloom). [ABSTRACT FROM AUTHOR]