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Several temperate tree species are expected to migrate northward and colonize boreal forests in response to climate change. Tree migrations could lead to transitions in forest types, but these could be influenced by several non-climatic factors, such as disturbances and soil conditions. We analysed over 10,000 forest inventory plots, sampled from 1970 to 2018 in meridional Québec, Canada, to identify what environmental conditions promote or prevent regional-scale forest transitions. We used a continuous-time multi-state Markov model to quantify the probabilities of transitions between forest states (temperate, boreal, mixed, pioneer) as a function of climate (mean temperature and climate moisture index during the growing season), soil conditions (pH and drainage) and disturbances (severity levels of natural disturbances and logging). We further investigate how different disturbance types and severities impact forests' short-term transient dynamics and long-term equilibrium using properties of Markov transition matrices. The most common transitions observed during the study period were from mixed to temperate states, as well as from pioneer to boreal forests. In our study, transitions were mainly driven by natural and anthropogenic disturbances and secondarily by climate, whereas soil characteristics exerted relatively minor constraints. While major disturbances only promoted transitions to the pioneer state, moderate disturbances increased the probability of transition from mixed to temperate states. Long-term projections of our model under the current environmental conditions indicate that moderate disturbances would promote a northward shift of the temperate forest. Moreover, disturbances reduced turnover and convergence time for all transitions, thereby accelerating forest dynamics. Contrary to our expectation, mixed to temperate transitions were not driven by temperate tree recruitment but by mortality and growth. Overall, our results suggest that moderate disturbances could catalyse rapid forest transitions and accelerate broad-scale biome shifts., (© 2020 John Wiley & Sons Ltd.)

Osborne, P.D. and Forest, A., 2016. Sediment dynamics from coast to slope - Southern Canadian Beaufort Sea. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 537-541. Coconut Creek (Florida), ISSN 0749-0208. Profound changes in cross-shelf sediment fluxes are anticipated in coming decades in the southern Canadian Beaufort Sea where an accelerated increase in temperature could lead to large changes in Arctic river hydrology and coastal-marine geomorphologic processes. In the past decade sediment exported to the Beaufort Shelf has increased while sea level pressure has increased accelerating the Beaufort Gyre, strengthening coastal upwelling and expanding the Mackenzie River plume offshore. Sea-ice extent has decreased while storminess has increased increasing wave action, coastal downwelling, current surge and resuspension and transport on the shoreface and shelf. This paper investigates mechanisms, quantities and rates of sediment transport operating in this cold continental shelf-slope environment. Past studies from more than 2 decades of research are compared with recent measurements to develop improved estimates of sediment sources, pathways, fate and fluxes across the shelf and slope. In particular, we explore connections between data from a long term mooring observatory deployed over the continental shelf and slope during the ArcticNet-Industry Partnership (2009-2011) and Beaufort Regional Environmental Assessment (BREA 2011-2015) to those acquired in studies focusing on nearshore and shoreface. Sediment fluxes from the Mackenzie River and erosion of permafrost coasts are compared with outer shelf-slope measurements of settling particles and near-bottom fluxes. In turn, the role of atmospheric and cryospheric processes in forcing sediment transfer from coast to slope is investigated to assess system response to changing climate and evaluate implications for marine hydrocarbon resource development along the continental margin of the Arctic Ocean. [ABSTRACT FROM AUTHOR]

Aim: The rapidly changing Arctic is ideal for investigating uncertainties in climate projections. Despite the challenges of collecting data in this region, an unprecedented large‐scale survey of shorebirds has been conducted over the last 30 years. Our study aimed to (1) develop probabilistic estimates for the change in suitable habitat for 10 Arctic shorebird species in Canada by 2075 and (2) assess the contribution of modelling decisions to the uncertainty in these estimates. Location: Arctic Canada. Methods: To evaluate uncertainty, we considered six classes of modelling decisions, yielding 216 unique projections for each species. We tested three decisions that are less commonly explored − the pool of candidate variables, a method for selecting variables, and the maximum distance of tree line dispersal, as well as the modelling algorithm, carbon emissions scenario, and global circulation model. We used a bootstrapping approach, creating a probability distribution for the proportional change in suitable habitat for each species. Results: Our findings indicated a substantial risk for 8/10 species to lose over half of their suitable breeding habitat, but this projection is much less certain than has been described previously. While much uncertainty is unexplained, we were surprised that the largest source of uncertainty among our modelling decisions was from our choice of methods for variable selection, that the other modelling decisions were relatively small sources of uncertainty, overshadowing other modelling decisions. Main Conclusions: While most scenarios predict a northward shift and significant habitat loss for Arctic‐breeding shorebirds, the Arctic Archipelago of Canada will remain an important refuge because in many other Arctic regions, there is no land farther north for these species to shift into. A comprehensive understanding of uncertainty is important for deciding if future projections can or should be used when planning climate‐resilient protected area networks. [ABSTRACT FROM AUTHOR]

As interest in outdoor activities in remote areas is increasing, there is a strong need for improved avalanche forecasting at the regional scale. Due to important logistical and safety matters, avalanche terrain measurements (avalanche observations, snowpack profiles, and stability tests) are not always possible for practitioners/forecasters. An interesting alternative would be to analyze the snowpack without these challenges by using snow model outputs. The SNOWPACK model is currently used operationally for avalanche forecasting and research in the Swiss Alps. Thus, this paper presents a summary of analyses that have been conducted to assess the potential of using the SNOWPACK model driven with bothin-situand forecasted meteorological data in three different Canadian climate and geomorphological contexts. A comparison of meteorological data fromin-situand predicted datasets for two winters shows that the GEMLAM weather model is the most accurate for the three climatic contexts of this project, but also showed a bias proportional to precipitation intensity/rate. Snow simulations forced with GEMLAM are the closest to field measurements. Finally, predictions of persistent weak layers have been validated using theInfoExplatform from Avalanche Canada. Crust and surface hoar formation dates agree with the information reported inInfoEx. [ABSTRACT FROM AUTHOR]

Non-arid region countries, including Canada, enjoy abundant water resources, while arid countries such as Qatar struggle to meet their water needs. However, climate change threats to water resources are similar for both climatic regions. Therefore, this article discusses water dimensions, security, and governance for these different regions, i.e., non-arid Canada and arid Qatar, that distinctly respond to their water-related challenges. Limitations of the article include lesser water-related literature availability for Qatar than for Canada. Canada's water resources appear vulnerable to climate change as it is projected to face >0.6 °C above the global average of 1.6 °C for the 20th-century temperature. Qatar is extremely vulnerable to dust storms, and rising sea levels, with the maximum temperature approaching 50 °C during the summer, and flooding during the winter. The sustainable use of water resources needs to address social, economic, political, climate change, and environmental dimensions of water. Other than climate change impacts and high per capita consumption of water, Qatar faces challenges of a rise in population (~29 million as of now), acute shortage of freshwater from rainfall (~80 mm per annum), high evapotranspiration (~95% of the total rainfall), depletion of groundwater, and low agricultural productivity due to infertile lands and water scarcity, all leading to food insecurity. The sustainable use of water resources requires improved regulations for water governance and management. Comparisons of water sustainability issues, dimensions, security, and governance facilitate discussions to improve water governance structures for resource sustainability, food security, and climate change adaptability, and show how one country could learn from the experiences of the other. [ABSTRACT FROM AUTHOR]

This study investigates the impacts of climate change on the hydrology and soil thermal regime of 10 sub‐arctic watersheds (northern Manitoba, Canada) using the Variable Infiltration Capacity (VIC) model. We utilize statistically downscaled and bias‐corrected forcing datasets based on 17 general circulation model (GCM) ‐ representative concentration pathways (RCPs) scenarios from phase 5 of the Coupled Model Intercomparison Project (CMIP5) to run the VIC model for three 30‐year periods: a historical baseline (1981–2010: 1990s), and future projections (2021–2050: 2030s and 2041–2070: 2050s), under RCPs 4.5 and 8.5. Future warming increases the average soil column temperature by ~2.2°C in the 2050s and further analyses of soil temperature trends at three different depths show the most pronounced warming in the top soil layer (1.6°C 30‐year−1 in the 2050s). Trend estimates of mean annual frozen soil moisture fraction in the soil column show considerable changes from 0.02 30‐year−1 (1990s) to −0.11 30‐year−1 (2050s) across the study area. Soil column water residence time decreases significantly (by 5 years) during the 2050s when compared with the 1990s as soil thawing intensifies the infiltration process thereby contributing to faster conversion to baseflow. Future warming results in 40%–50% more baseflow by the 2050s, where it increases substantially by 19.7% and 46.3% during the 2030s and 2050s, respectively. These results provide crucial information on the potential future impacts of warming soil temperatures on the hydrology of sub‐arctic watersheds in north‐central Canada and similar hydro‐climatic regimes. [ABSTRACT FROM AUTHOR]

Few records of spring paleoclimate are available for boreal Canada, as biological proxies recording the beginning of the warm season are uncommon. Given the spring warming observed during the last decades, and its impact on snowmelt and hydrological processes, searching for spring climate proxies is receiving increasing attention. Tree‐ring anatomical features and intra‐annual widths were used to reconstruct the regional March to May mean air temperature from 1770 to 2016 in eastern boreal Canada. Nested principal component regressions calibrated on 116 years of gridded temperature data were developed from one Fraxinus nigra and 10 Pinus banksiana sites. The reconstruction indicated three distinct phases in spring temperature variability since 1770. Ample phases of multi‐decadal warm and cold springs persisted until the end of the Little Ice Age (1850–1870 CE) and were gradually replaced since the 1940s by decadal to interannual variability associated with an increase in the frequency and magnitude of warm springs. Significant correlations with other paleotemperature records, gridded snow cover extent and runoff support that historical high flooding were associated with late, cold springs with heavy snow cover. Most of the high magnitude spring floods reconstructed for the nearby Harricana River also coincided with the lowest reconstructed spring temperature per decade. However, the last 40 years of observed and reconstructed mean spring temperature showed a reduction in the number of extreme cold springs contrasting with the last few decades of extreme flooding in the eastern Canadian boreal region. This result indicates that warmer late spring mean temperatures on average may contribute, among other factors, to advance the spring break‐up and to likely shift the contribution of snow to rain in spring flooding processes. [ABSTRACT FROM AUTHOR]

Fire activity in 288 areas (2.5° N × 10° E) in the Arctic region (50°–70° N, 0°–360° E) was analyzed using about 4.4 million satellite hotspot (HS) data from 2002 to 2021. A total of 21 high fire density areas from eastern Europe to western Canada were selected, and their fire–weather conditions during each active fire period were analyzed using about 1820 various weather maps at the upper and the lower air level. Analysis results showed that the active fires in the Arctic region occurred under the fire–weather conditions associated with the northward movement of cut-off high (COH) and warm air masses detached from the south caused by large westerly meandering (LWM). LWM is a sign of the beginning of an active fire period. Very active fires on HS peak days occurred several days after the start of the northward movement of COHs and under mainly high-pressure conditions in the upper air and strong wind conditions in the lower air. The time lag of these several days suggests that we may be prepared for very active fires. The fire–weather analysis approach described in this paper has shown that future large-scale fire outbreaks are predictable. [ABSTRACT FROM AUTHOR]

The sensitivity of amphibian species to shifts in environmental conditions has been exhibited through long‐term population studies and the projection of ecological niche models under expected conditions. Species in biodiversity hotspots have been the focus of ample predictive modeling studies, while, despite their significant ecological value, wide‐ranging and common taxa have received less attention. We focused on predicting range restriction of the spotted salamander (Ambystoma maculatum), blue‐spotted salamander (A. laterale), four‐toed salamander (Hemidactylium scutatum), and red‐backed salamander (Plethodon cinereus) under future climate scenarios. Using bias‐corrected future climate data and biodiversity database records, we developed maximum entropy (MaxEnt) models under current conditions and for climate change projections in 2050 and 2070. We calculated positivity rates of species localities to represent proportions of habitat expected to remain climatically suitable with continued climate change. Models projected under future conditions predicted average positivity rates of 91% (89–93%) for the blue‐spotted salamander, 23% (2–41%) for the spotted salamander, 4% (0.7–9%) for the four‐toed salamander, and 61% (42–76%) for the red‐backed salamander. Range restriction increased with time and greenhouse gas concentration for the spotted salamander, four‐toed salamander, and red‐backed salamander. Common, widespread taxa that often receive less conservation resources than other species are at risk of experiencing significant losses to their climatic ranges as climate change continues. Efforts to maintain populations of species should be focused on regions expected to experience fewer climatic shifts such as the interior and northern zones of species' distributions. [ABSTRACT FROM AUTHOR]

Climate change refugia are areas that are relatively buffered from contemporary climate change and may be important safe havens for wildlife and plants under anthropogenic climate change. Topographic variation is an important driver of thermal heterogeneity, but it is limited in relatively flat landscapes, such as the boreal plain and prairie regions of western Canada. Topographic variation within this region is mostly restricted to river valleys and hill systems, and their effects on local climates are not well documented. We sought to quantify thermal heterogeneity as a function of topography and vegetation cover within major valleys and hill systems across the boreal–grassland transition zone. Using iButton data loggers, we monitored local temperature at four hills and 12 river valley systems that comprised a wide range of habitats and ecosystems in Alberta, Canada (N = 240), between 2014 and 2020. We then modeled monthly temperature by season as a function of topography and different vegetation cover types using general linear mixed effect models. Summer maximum temperatures (Tmax) varied nearly 6°C across the elevation gradient sampled. Local summer mean (Tmean) and maximum (Tmax) temperatures on steep, north‐facing slopes (i.e., low levels of potential solar radiation) were up to 0.70°C and 2.90°C cooler than highly exposed areas, respectively. Tmax in incised valleys was between 0.26 and 0.28°C cooler than other landforms, whereas areas with greater terrain roughness experienced maximum temperatures that were up to 1.62°C cooler. We also found that forest cover buffered temperatures locally, with coniferous and mixedwood forests decreasing summer Tmean from 0.23 to 0.72°C and increasing winter Tmin by up to 2°C, relative to non‐forested areas. Spatial predictions of temperatures from iButton data loggers were similar to a gridded climate product (ClimateNA), but the difference between them increased with potential solar radiation, vegetation cover, and terrain roughness. Species that can track their climate niche may be able to compensate for regional climate warming through local migrations to cooler microsites. Topographic and vegetation characteristics that are related to cooler local climates should be considered in the evaluation of future climate change impacts and to identify potential refugia from climate change. [ABSTRACT FROM AUTHOR]

Climate change poses a significant threat to Arctic freshwater biodiversity, but impacts depend upon the strength of organism response to climate‐related drivers. Currently, there is insufficient knowledge about Arctic freshwater biodiversity patterns to guide assessment, prediction, and management of biodiversity change.As part of the Circumpolar Biodiversity Monitoring Program's first freshwater assessment, we evaluated diversity of diatoms, benthic macroinvertebrates, and fish in North American Arctic rivers. Alpha diversity was assessed in relation to temperature, water chemistry, bedrock geology, and glaciation history to identify important environmental correlates. Biotic composition was compared among groups to evaluate response to environmental gradients.Macroinvertebrate α‐diversity declined strongly with increasing latitude from 48°N to 82°N, whereas diatom and fish diversity peaked around 70°N without a clear latitudinal decline. Macroinvertebrate diversity was significantly positively related to air temperature. Diatom diversity was related to bedrock geology and temperature, whereas fish diversity was related to glaciation history.Fish and macroinvertebrate assemblages differed between sites in western Canada, where invertebrate composition was more variable, and Alaska, where fish composition was more variable. In sites with both diatom and macroinvertebrate data, diatom composition was distinct in Alaska, where richness was highest in former glacial refugia. Macroinvertebrate composition was distinct in lowest‐latitude eastern and high‐latitude western Canadian sites where temperature was highest.Temperature, precipitation, geology, calcium, and substrate size were important environmental correlates for diatoms and macroinvertebrates, although the relative importance of each correlate differed. Diatom taxa were most strongly associated with water chemistry, whereas benthic invertebrate composition related most strongly to precipitation and temperature.This large‐scale study provides the most substantial integration and analysis of river diatom, macroinvertebrate, and fish data from the North American Arctic to date. Findings suggest that macroinvertebrates will show the strongest response to climate‐related shifts in temperature, whereas diatoms and fish are more likely to respond to climate‐induced shifts in nutrients and hydraulic connectivity. However, significant gaps in data coverage limited our ability to reliably evaluate spatial patterns and detect change. These gaps could be reduced by improving collaborative efforts between the U.S.A. and Canada to harmonise future monitoring. [ABSTRACT FROM AUTHOR]

A stochastic rainwater harvesting system modeling (StRaHaS) method is developed to enhance both accurateness and applicability of hydrologic modeling in guiding extensive applications of individual rainwater harvesting (RWH) systems (especially over large data‐scarce regions). The reliability of a RWH system is characterized as the fraction of time water demands being satisfied by a rainwater storage unit (RWSU). The variations of water balances, the post‐rainfall RWSU full‐storage probability, and the system reliability with random rainfall features, variable water demands, and the other RWH system characteristics are derived as analytical, accurate, and easily applied models through stochastic integration. StRaHaS is applied to three domestic RWH systems in Toronto, Canada. Due to high accurateness and low complexity in modeling, designing, assessing, and analyzing the RWH systems, StRaHaS outperforms existing methods (e.g., inaccurate water‐balance estimation, complicated continuous simulation, and simplified stochastic simulation). Based on StRaHaS, we quantitatively expound the increases in the reliability of the systems with higher rainwater supplies (corresponding to higher rainfall depths, and lower rainfall losses and first‐flush depths), lower water demands (in shorter wet and dry periods), and higher RWSU capacities. Long dry periods are lengthened by climate change and play dominant roles in low, spatially heterogeneous reliability of the systems. Synchronic changes and extremely high values of rainfall features do not significantly affect the reliability. Overall, StRaHaS is a promising method in modeling RWH systems, revealing RWH mechanisms, scientizing RWH applications, and facilitating the Sustainable Development Goals for addressing global water issues. Key Points: Accurate & simple models to simulate, design, assess, and analyze rainwater harvesting systems under random rainfalls and variable water demandsInsignificant changes of water‐supply reliability of the systems with removing synchronic changes or high extremes of rainfall featuresLong dry periods are lengthened by climate change, and dominate low, spatially heterogeneous reliability of the systems in Toronto, Canada [ABSTRACT FROM AUTHOR]

Purpose: The paper aims to respond to three questions: Are Canadian organizations committed to sustainability? Are there any links between sustainability and records management and archives programs? And, to what extent are records managers, archivists and technologists engaged in climate action? The paper also provides background on climate change in the Canadian and global contexts, defines relevant terminology, and presents a literature review that positions sustainability, adaptation and mitigation in relation to records management and archives. Design/methodology/approach: The paper is based on qualitative participatory research involving expert interviews in 24 government agencies, universities and businesses located in 10 Canadian cities. Findings: The organizations in the study are committed to sustainability and have developed significant programs and activities in support of this aim. Although the records managers, archivists and technologists interviewed are involved in related activities, there is a gap between what they are doing as a matter of course and the wider sustainability efforts of their parent organizations. As resources are tight, sustainability measurement entails more work and there are no real incentives to add sustainability components to programs, the participants are focused on delivering the programs they are hired to do. As a result, there is a sense of serendipity around outcomes that do occur – "sometimes, green is the outcome". Research limitations/implications: This paper presents the results of research conducted at 24 organizations in 10 Canadian cities, a small but meaningful sample that provides a springboard for considering climate action in records and archives. Based on the discussion, there is a need for a records and archives agenda that directly responds the United Nation's climate action targets: strengthening resilience and adaptive capacity to climate-related hazards and natural disasters; integrating climate change measures into policies, strategies and planning; and improving education, awareness-raising and human institutional capacity on climate change mitigation, adaptation, impact reduction and early warning. In support of this aim, the paper charts possible material topics from the literature and compares these with research findings. Practical implications: From a top-down perspective, organizations need to expand sustainability programs to address all business areas, including records and archives. From a bottom-up perspective, records managers and archivists should include adaptation in disaster planning and consider the program benefits of developing economic, environmental and social sustainability initiatives to mitigate climate change. Originality/value: The paper defines resilience, sustainability, adaption and mitigation and positions these terms in records management and archives. The paper examines how records managers, archivists and technologists think about sustainability; where sustainability intersects with records and archives work; and how records managers and archivists can engage in climate action. [ABSTRACT FROM AUTHOR]

There is growing recognition that gender diversity within research organizations can result in innovative research outcomes. It has also been recognized that gender homogeneity can undermine the quality and breadth of the research and may allow some to cast doubt on the legitimacy of scientific findings. In this paper, we present the results of a gender-based analysis of Canada's ArcticNet Networks Centers of Excellence. Representing Canada's single largest commitment to climate change science, ArcticNet has involved 761 researchers who have published >2400 peer-reviewed publications on the impacts of climate change in the Canadian Arctic. Our results indicate that, despite outnumbering their male peers at the graduate levels, the representation of women within ArcticNet exhibits a marked decline to only 21% (N = 51) of all ArcticNet investigators (N = 246). In addition to being numerically under-represented, female investigators in ArcticNet have fewer research collaborators and are generally less integrated into the network as compared to their male colleagues. Male investigators tend to form homophilious ties—publishing predominately with other males, whereas female investigators have heterophilious collaborations, with fewer peer-reviewed journal articles. Given the complexities of climate change research, particularly in the Arctic where the impacts of climate change are projected to be most extreme, the equitable inclusion of female scientists and other under-represented groups is crucial if sustainable solutions are to be found. [ABSTRACT FROM AUTHOR]

Pronounced climate warming over the arctic‐subarctic regions has lead to profound hydrological changes including intensified river flow, but how soil frost controls aquifer discharge remains poorly understood. This study quantifies the relationship between freezing temperature and baseflow in winter. Analyses show that the traditional reservoir models are unable to reproduce the observed baseflow variations. By incorporating a freezing temperature function in the reservoir models, the model performances are largely improved. It indicates the dominant role of freezing temperature in controlling the aquifer discharge through reducing the watershed conductivity and liquid (active) water content. The results for the Albany watershed in Canada show that the watershed lump conductivity decreases by half when air temperature accumulates to −172 °C·day from winter start and in extremely cold years, it could decrease by more than 85%. With this relationship, a climate warming of +1, +2, and +4 °C would suggest an increase of 7.7%, 16.7%, and 41.0% in conductivity or 6.8%, 14.7%, and 35.0% in winter discharge, respectively. The study provides an important link between climate warming and aquifer discharge in cold regions. The results could be particularly useful for developing process‐based models, estimating baseflow variations, and assessing climate change impact on cold region hydrology. Plain Language Summary: Pronounced climate warming over the arctic‐subarctic regions has lead to intensified river flow, but how soil frost controls aquifer discharge remains poorly understood. This study reveals the relationship between freezing temperature and baseflow in winter. The results show that freezing temperature reduces baseflow through decreasing hydraulic conductivity by more than 85% in extremely cold years for the Albany watershed in Canada. As such, a climate warming of +1, +2, and +4 °C could result in an increase in winter aquifer discharge of 6.8%, 14.7%, and 35.0%, respectively. The temperature‐baseflow relationship found in this study provides new insight for cold region climate change impact and water resources studies. Key Points: Freezing temperature is the dominant factor controlling cold region winter baseflowSoil frost reduces baseflow by reducing hydraulic conductivity and active water contentClimate warming could significantly increase winter river flow in cold regions [ABSTRACT FROM AUTHOR]

There is increasing interest in community-based environmental monitoring (CBEM) in Canada's North in response to the rising impacts of resource exploitation and climate change, and with increased recognition of indigenous knowledge. IMALIRIJIIT, meaning those who study water in Inuktitut, is a CBEM program involving science land camps, capacity-building workshops, and scientific data collection with the participation of youth, elders, local experts, and researchers. It was coinitiated by the Inuit community of Kangiqsualujjuaq (Nunavik, Quebec) and university researchers. This hands-on and land-based program aims to establish a sustainable environmental monitoring program of the George River, before the start of a rare earth elements (REEs) mining project in its upper watershed. The community was concerned about potential impacts on the river, as it is crucial to fishing, hunting, and gathering. The community therefore wanted its own independent and long-term environmental monitoring program to collect baseline data and promote local capacity-building. IMALIRIJIIT includes water-quality measurements, bio-indicators, contaminant and REE biomonitoring in traditional food, remote-sensing analysis of water-quality parameters and vegetation change at the watershed scale, as well as interactive mapping of traditional ecological. IMALIRIJIIT outcomes and challenges are discussed to identify conditions for successful implementation of CBEM and environmental stewardship. [ABSTRACT FROM AUTHOR]

Abstract: In many forested ecosystems, it is increasingly recognized that the probability of burning is substantially reduced within the footprint of previously burned areas. This self‐limiting effect of wildland fire is considered a fundamental emergent property of ecosystems and is partly responsible for structuring landscape heterogeneity (i.e., mosaics of different age classes), thereby reducing the likelihood of uncharacteristically large fires in regions with active fire regimes. However, the strength and longevity of this self‐limiting phenomenon is not well understood in most fire‐prone ecosystems. In this study, we quantify the self‐limiting effect in terms of its strength and longevity for five fire‐prone study areas in western North America and investigate how each measure varies along a spatial climatic gradient and according to temporal (i.e., annual) climatic variation. Results indicate that the longevity (i.e., number of years) of the self‐limiting effect ranges between 15 yr in the warm and dry study area in the southwestern United States to 33 yr in the cold, northern study areas in located in northwestern Montana and the boreal forest of Canada. We also found that spatial climatic variation has a strong influence on wildland fire's self‐limiting capacity. Specifically, the self‐limiting effect within each study area was stronger and lasted longer in areas with low mean moisture deficit (i.e., wetter and cooler settings) compared to areas with high mean moisture deficit (warmer and drier settings). Last, our findings show that annual climatic variation influences wildland fire's self‐limiting effect: drought conditions weakened the strength and longevity of the self‐limiting effect in all study areas, albeit at varying magnitudes. Overall, our study provides support for the idea that wildland fire contributes to spatial heterogeneity in fuel ages that subsequently mediate future fire sizes and effects. However, our findings show that the strength and longevity of the self‐limiting effect varies considerably according to spatial and temporal climatic variation, providing land and fire managers relevant information for effective planning and management of fire and highlighting that fire itself is an important factor contributing to fire‐free intervals. [ABSTRACT FROM AUTHOR]

In Canada, risk of flooding due to heavy rainfall has risen in recent decades; the most notable recent examples include the July 2013 storm in the Greater Toronto region and the May 2017 flood of the Toronto Islands. We investigate nonstationarity and trends in the short-duration precipitation extremes in selected urbanized locations in Southern Ontario, Canada, and evaluate the potential of nonstationary intensity-duration-frequency (IDF) curves, which form an input to civil infrastructural design. Despite apparent signals of nonstationarity in precipitation extremes in all locations, the stationary vs. nonstationary models do not exhibit any significant differences in the design storm intensity, especially for short recurrence intervals (up to 10 years). The signatures of nonstationarity in rainfall extremes do not necessarily imply the use of nonstationary IDFs for design considerations. When comparing the proposed IDFs with current design standards, for return periods (10 years or less) typical for urban drainage design, current design standards require an update of up to 7 %, whereas for longer recurrence intervals (50-100 years), ideal for critical civil infrastructural design, updates ranging between ∼ 2 and 44% are suggested. We further emphasize that the above findings need re-evaluation in the light of climate change projections since the intensity and frequency of extreme precipitation are expected to intensify due to global warming. [ABSTRACT FROM AUTHOR]

BACKGROUND: A number of studies have assessed possible climate change impacts on the Lyme disease vector, Ixodes scapularis. However, most have used surface air temperature from only one climate model simulation and/or one emission scenario, representing only one possible climate future. OBJECTIVES: We quantified effects of different Representative Concentration Pathway (RCP) and climate model outputs on the projected future changes in the basic reproduction number (R0) of I. scapularis to explore uncertainties in future R0 estimates. METHODS: We used surface air temperature generated by a complete set of General Circulation Models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to hindcast historical (1971-2000), and to forecast future effects of climate change on the R0 of I. scapularis for the periods 2011-2040 and 2041-2070. RESULTS: Increases in the multimodel mean R0 values estimated for both future periods, relative to 1971-2000, were statistically significant under all RCP scenarios for all of Nova Scotia, areas of New Brunswick and Quebec, Ontario south of 47°N, and Manitoba south of 52°N. When comparing RCP scenarios, only the estimated R0 mean values between RCP6.0 and RCP8.5 showed statistically significant differences for any future time period. CONCLUSION: Our results highlight the potential for climate change to have an effect on future Lyme disease risk in Canada even if the Paris Agreement's goal to keep global warming below 2°C is achieved, although mitigation reducing emissions from RCP8.5 levels to those of RCP6.0 or less would be expected to slow tick invasion after the 2030s. [ABSTRACT FROM AUTHOR]

Recent flood events in Canada have led to speculation that changes in flood behaviour are occurring; these changes have often been attributed to climate change. This paper examines flood data for a collection of 132 gauging stations in Canada. All of these watersheds are part of the Canadian Reference Hydrometric Basin Network (RHBN), a group of gauging stations specifically assembled to assist in the identification of the impacts of climate change. The RHBN stations are considered to have good quality data and were screened to avoid the influences of regulation, diversions, or land use change. Daily flow data for each watershed are used to derive a peaks over threshold (POT) dataset. Several measures of flood behaviour are examined based on the POT data, which afford a more in-depth analysis of flood behaviour than can be obtained using annual maxima data. Analysis is conducted for four time periods ranging from 50 to 80 years in duration; the latter period results in a much smaller number of watersheds that have data for the period. The changes in flood responses of the watersheds are summarized by grouping the watersheds by size (small, medium, and large) and also by hydrologic regime (nival, mixed, and pluvial). The results provide important insights into the nature of the changes that are occurring in flood regimes of Canadian rivers, which include more flood exceedances, reduced maximum flood exceedance magnitudes for snowmelt events, and earlier flood events. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Climate drives ecosystem processes and impacts biodiversity. Biodiversity patterns over large areas, such as Canada's boreal, can be monitored using indirect indicators derived from remotely sensed imagery. In this paper, we characterized the historical space–time relationships between climate and a suite of indirect indicators of biodiversity, known as the Dynamic Habitat Index (DHI) to identify where climate variability is co-occurring with changes in biodiversity indicators. We represented biodiversity using three indirect indicators generated from 1987 to 2007 National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer images. By quantifying and clustering temporal variability in climate data, we defined eight homogeneous climate variability zones, where we then analyzed the DHI. Results identified unique areas of change in climate, such as the Hudson Plains, that explain significant variations in DHI. Past variability in temperatures and growing season index had a strong influence on observed vegetation productivity and seasonality changes throughout Canada's boreal. Variation in precipitation, for most of the area, was not associated with DHI changes. The methodology presented here enables assessment of spatial–temporal relationships between biodiversity and climate variability and characterizes distinctive zones of variation that may be used for prioritization and planning to ensure long-term biodiversity conservation in Canada. [ABSTRACT FROM PUBLISHER]

Community-based adaptation ( CBA) has emerged over the last decade as an approach to empowering communities to plan for and cope with the impacts of climate change. While such approaches have been widely advocated, few have critically examined the tensions and challenges that CBA brings. Responding to this gap, this article critically examines the use of CBA approaches with Inuit communities in Canada. We suggest that CBA holds significant promise to make adaptation research more democratic and responsive to local needs, providing a basis for developing locally appropriate adaptations based on local/indigenous and Western knowledge. Yet, we argue that CBA is not a panacea, and its common portrayal as such obscures its limitations, nuances, and challenges. Indeed, if uncritically adopted, CBA can potentially lead to maladaptation, may be inappropriate in some instances, can legitimize outside intervention and control, and may further marginalize communities. We identify responsibilities for researchers engaging in CBA work to manage these challenges, emphasizing the centrality of how knowledge is generated, the need for project flexibility and openness to change, and the importance of ensuring partnerships between researchers and communities are transparent. Researchers also need to be realistic about what CBA can achieve, and should not assume that research has a positive role to play in community adaptation just because it utilizes participatory approaches. WIREs Clim Change 2016, 7:175-191. doi: 10.1002/wcc.376 For further resources related to this article, please visit the . [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ongoing climate change is likely to result in shifts in successional dynamics in boreal mixedwood stands. Using data from provincial forest inventory databases, we examined the occurrence and abundance of the regeneration of various coniferous species (white spruce, black spruce and balsam fir) along an east-west Canadian gradient in aspen-dominated stands. The interpretation of the results was based on environmental conditions, including climate, natural fire regime and human impacts. We found that conifer regeneration was present in aspen stands along the entire gradient, despite differences in climatic conditions and fire regimes between the west (warmer and drier, with large recurrent fires) and east (more humid with relatively long fire cycles). However, abundance and distribution varied from one conifer species to the next. The abundance of white spruce decreased towards the eastern end of the longitudinal gradient, while balsam fir and black spruce abundance decreased towards the west. Although abundance decreased, balsam fir and black spruce regeneration was still present in western Canada. This study shows that it is difficult to interpret the effects of climate change on conifer recruitment without accounting for the superimposed effects of human activities. [ABSTRACT FROM AUTHOR]

Climate warming in Arctic Canada, e.g., permafrost thaw, comprehensively impacts biota and the environment, which then affects the lives of people. This study aimed to investigate which perceived environmental and adaptation factors relate to self-rated well-being, quality of life, satisfaction with life (sum variable = life balance), self-rated health, and feeling of empowerment to face the changes related to permafrost thaw. The study sample was collected from one community using a questionnaire (n = 53) and analyzed by cross-tabulation. Results indicated that most participants had at least good well-being, quality of life, satisfaction with life, and a medium level of health, and over 40% assessed being empowered to face the changes related to permafrost thaw. Problems and challenges associated with permafrost thaw, e.g., health, traditional lifeways, and infrastructure, were recognized; these had impacts on life balance, feeling of empowerment, and self-rated health. Traditional knowledge regarding adaptation to face changes was seen as important. More adaptation actions from the individual to global level seemed to be needed. This study provides an overview of the situation in one area, but more research, with a larger study sample, should be conducted to achieve a deeper understanding of climate-related impacts on life and holistic well-being. [ABSTRACT FROM AUTHOR]