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The role of forest management in mitigating climate change is a central concern for the Canadian province of British Columbia. The successful implementation of forest management activities to achieve climate change mitigation in British Columbia will be strongly influenced by public support or opposition. While we now have increasingly clear ideas of the management opportunities associated with forest mitigation and some insight into public support for climate change mitigation in the context of sustainable forest management, very little is known with respect to the levels and basis of public support for potential forest management strategies to mitigate climate change. This paper, by describing the results of a web-based survey, documents levels of public support for the implementation of eight forest carbon mitigation strategies in British Columbia’s forest sector, and examines and quantifies the influence of the factors that shape this support. Overall, respondents ascribed a high level of importance to forest carbon mitigation and supported all of the eight proposed strategies, indicating that the British Columbia public is inclined to consider alternative practices in managing forests and wood products to mitigate climate change. That said, we found differences in levels of support for the mitigation strategies. In general, we found greater levels of support for a rehabilitation strategy (e.g. reforestation of unproductive forest land), and to a lesser extent for conservation strategies (e.g. old growth conservation, reduced harvest) over enhanced forest management strategies (e.g. improved harvesting and silvicultural techniques). We also highlighted multiple variables within the British Columbia population that appear to play a role in predicting levels of support for conservation and/or enhanced forest management strategies, including environmental values, risk perception, trust in groups of actors, prioritized objectives of forest management and socio-demographic factors. [ABSTRACT FROM AUTHOR]

This paper provides an overview of a collaborative study on visualizing climate change at the local scale. A conceptual framework has been developed, in which local scenarios and visualizations of climate change impacts and response were created to facilitate local dialogue on incorporating climate change into long-term planning and implementation of community development decisions. As part of a larger effort to generate a new integrated participatory visioning process, this paper describes a case study of the District of North Vancouver which created visualizations of changing mountain snow and landscape conditions, and provides new insights on issues and dilemmas in using realistic landscape visualizations to depict scientific modelling projections, local responses to climate change, and uncertainty. Results from this study suggest that the visualizations, and subsequent dialogue sessions, did influence emotional response to climate change as well as self-assessed understanding of adaptation and mitigation response options. However, there is a need to test this visioning process with larger heterogeneous groups of participants in order to better assess its effectiveness in enabling dialogue on local responses to climate change. [ABSTRACT FROM AUTHOR]

This paper examines the employment impact of British Columbia's revenue-neutral carbon tax implemented in 2008. While all industries appear to benefit from the redistributed tax revenues, the most carbon-intensive and trade-sensitive industries see employment fall with the tax, while clean service industries see employment rise. By aggregating across industries I find the BC carbon tax generated, on average, a small but statistically significant 0.74 percent annual increases in employment over the 2007–2013 period. This paper provides initial evidence showing how a revenue-neutral carbon tax may not adversely affect employment. [ABSTRACT FROM AUTHOR]

• Assessment framework reveals progress in climate action planning in BC, Canada. • City differences clear: Victoria and Vancouver ahead of Surrey in sustainable paths. • Partnerships have been critical for supporting engagement in climate action. • Conditioning cities to report climate action progress has set a successful standard. • Feedback through self-assessment needed to identify most effective climate actions. To transition to a more sustainable and low-carbon economy, a series of local governments in British Columbia, Canada, are implementing climate action and innovation. This is largely in response to a need for societal changes in current development paths. However, there has been a lack of studies assessing the effectiveness of these actions and whether these municipalities are on track to meet their targets. This paper tests a newly developed assessment framework to evaluate local government actions and to better understand city-wide community development paths in three major cities in British Columbia—Vancouver, Victoria and Surrey. This assessment reveals notable progress in their transitions to sustainable pathways in areas such as agenda setting and strategy, plan formulation and implementation, and these sometimes result in transformative actions. Nonetheless, a gap between these actions and their performance reveals that local governments from this study are failing to properly address the current climate emergency. In particular, the municipalities lack processes for evaluating their progress in changing their current paths. This reduces their capacity to identify best practices to improve the effectiveness of climate actions and also hinders their ability to act on feedback and make adjustments to meet their stated goals and targets. [ABSTRACT FROM AUTHOR]

Local governments have a key role to play in implementing climate innovations as they have jurisdiction over a significant portion of greenhouse gas emissions. Meeting the Climate Change Challenge (MC3) is the first longitudinal study exploring climate innovation in Canadian municipalities. A tri-university research collaborative, it focuses on British Columbia (BC), whose voluntary efforts to set and meet climate change goals were far more ambitious than those offered by the federal government (and almost any other province in North America at the time). These efforts included introducing a carbon tax and the Climate Action Charter voluntary agreement in 2007. Since then, 187 of the 190 local governments in BC have signed the Charter to take action on climate change. Research in the first phase of MC3explored the dynamics of innovative local responses to the coordinated suite of government legislation, complimentary policy instruments, financial incentives and partnerships with quasi-institutional partners. In the second phase, the 11 original case studies were revisited to explore the nature of transformative change in development paths and indicators of change. Methods include sentiment analysis, decomposition analysis of regional/local emissions, and modelling relationships between climate action co-benefits and trade-offs. This paper provides a synthesis of research outcomes and their implications for environmental governance at multiple scales and the potential of policy innovations to accelerate transformation towards carbon neutral economies. Key policy insights Local governments are on the front line of identifying indicators of change in current development paths and policy innovations to effect the necessary changes for transformation to carbon neutral economies. Barriers to transformational change include lack of coordination or concerted action across multiple scales of governance, electoral cycles and large swings in leadership, and lack of policy coherence across governance levels. Drivers of climate innovation include leadership at multiple levels of governance. Understanding the co-benefits (and trade-offs) of climate actions is important for integrated strategies that achieve broader sustainability goals, as well as accelerating more innovations on climate change. [ABSTRACT FROM AUTHOR]

While multifaceted, a chief aim when designating parks and protected areas is to support the preservation of biological diversity, in part, through representing and conserving the full range of landscape conditions observed throughout a representative area. Parks and protected areas are, however, typically developed using a static interpretation of current biodiversity and landscape conditions. The observed and potential climate change impacts to biodiversity have created a need to also contemplate how parks and protected areas will respond to climate change and how these areas will represent the future range of landscape conditions. To assess change in biodiversity, broad-scale ecosystem information can be sourced from indirect remotely sensed indicators. Quantifying biodiversity through indirect indicators allows characterization of inter-relationships between climate and biodiversity. Such characterizations support the assessment of possible implications of climatic change, as the indicators can be generated using modeled forecasts of future climatic conditions. In this paper we model and map impacts of climate change on British Columbia's parks and protected areas by quantifying change in a number of remotely sensed indicators of biodiversity. These indicators are based on the measured amount of incoming solar energy used by vegetation and map the overall annual energy utilization, variability (seasonality), and latent or baseline energy. We compare current conditions represented by parks and protected areas, to those forecasted in the year 2065. Our results indicate that parks and protected areas are forecasted to become more productive and less seasonal, due to increased vegetation productivity in higher elevation environments. While increased vegetation productivity may be beneficial for biodiversity overall, these changes will be particularly problematic for sensitive and specialist species. Future gaps in vegetation conditions protected by parks and protected areas are observed in the eastern edge of the Rocky Mountains and the central interior region of British Columbia. Protected areas along the Coast Mountains, Vancouver Island highlands, and the Rocky Mountains show the greatest levels of change in the biodiversity indicators, including decreasing seasonality, with the Mountain Hemlock ecozone most at risk. Examples of large parks that are predicted to experience rapid change in vegetation characteristics include Strathcona, Garabaldi, and Kitlope. Our maps of future spatial distributions of indirect biodiversity indicators fill a gap in information products available for adaptive parks management and provide an opportunity for dialogue and further research on the use of future scenarios of landscape conditions in conservation planning. [ABSTRACT FROM AUTHOR]

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.)

Abstract: In dendrochronology, temporal patterns in radial growth are considered an expression of historical climate processes that cannot be measured. Dendrochronological networks, developed to characterize the geographical and temporal patterns of tree rings, have additional spatial information that can add to our understanding of historical climate conditions. This paper summarizes the use of spatial autocorrelation statistical tools for quantifying spatial trends in dendrochronological networks. Using this approach it is possible to characterize the spatial nature of the process influencing radial growth trends within a tree-ring network. Using a local or mapable measure of spatial autocorrelation it is possible to locate clusters of similar and extreme radial growth trends in any given year and to characterize the persistence of spatial patterns of growth through time. Applied to a dendrochronological network of yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach), our results suggest that spatial patterns in extreme growth are most often associated with growth limiting climate processes. [Copyright &y& Elsevier]

Information about several papers discussed at a meeting held at the University of Victoria in British Columbia on tropical meteorology is presented. Topics include the importance and complexity of tropical meteorology, the impact of atmospheric convection on local and large scale circulations in the tropics, and the usability of general circulation models (GCMs). The meeting featured several meteorologists including Andrew Majda, Philip Austin and John Scinocca.

Copyright of Canadian Entomologist is the property of Cambridge University Press 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.)

Jökulhlaups from lakes dammed by Tulsequah Glacier in northwestern British Columbia have occurred regularly since the early twentieth century. The floods commenced after decades of downwasting and retreat of the glacier from its Holocene maximum position, which it achieved in the nineteenth century. Hydrometric data and other records are used to reconstruct the times and peak discharges of floods from two glacier-dammed lakes. Tulsequah Lake formed in the early 1900s when a tributary glacier separated from Tulsequah Glacier, creating an ice-free embayment between the two. The lake grew rapidly in surface area and volume in the first half of the twentieth century, but later, with continued glacier retreat, it decreased in size. The first jökulhlaups from Tulsequah Lake were the largest. Peak and total discharges decreased as the lake became smaller. Today, Tulsequah Lake is small, and it will disappear completely if Tulsequah Glacier retreats any further. A second lake (Lake No Lake), however, has formed and grown in size as Tulsequah Lake has diminished. Lake No Lake developed from a subglacial water body in a tributary valley, 7 km upglacier from Tulsequah Lake. Like Tulsequah Lake, Lake No Lake rapidly grew in area and volume during its youth, and in the 1970s it began to generate its own jökulhlaups. Lake No Lake appears to be following the same evolutionary path as Tulsequah Lake – its volume is now decreasing due to downwasting of Tulsequah Glacier, and its jökulhlaups are beginning to diminish. As Tulsequah Glacier continues to shrink in response to climatic warming, additional glacier-dammed lakes may form, renewing the cycle of outburst flood activity. Such behaviour can be expected in other high mountains because most alpine glaciers are retreating in response to global warming. [ABSTRACT FROM AUTHOR]

Excitation of basin‐scale, internal waves (i.e., internal seiches) in lakes require spatially homogeneous wind fields that vary on time scales comparable to the seiche period, which can be on the order of several days in large lakes. We evaluate 2 years (October 1, 2016 to September 30, 2018) of 15‐min wind data from a shore‐based meteorological station to identify strong wind episodes likely to excite internal seiches in a large and geometrically complex lake surrounded by convoluted topography, Quesnel Lake, British Columbia, Canada. Our findings include the identification of strong wind event seasonality, with peak mean monthly wind speeds in April and November, and minimum mean monthly wind speeds in August. Using geopotential heights (GPHs) from 1.5° × 1.5° gridded reanalysis data to reconstruct the atmospheric state for each strong wind episode, two primary synoptic patterns are identified that, in conjunction with local topographic channelling, lead to either easterlies or westerlies occurring at our sampling station, with strong easterly episodes three times more frequent than westerly episodes. This highlights the important role that developing low‐pressure systems in the Northeastern Pacific Basin have in setting up the GPH gradient required for persistent strong winds at Quesnel Lake, in the hours and days before these storms make landfall. The projection of synoptic patterns of strong wind events onto a 4 × 3 self‐organizing map clustered strong wind events by mean wind direction, similar to the results of a manual classification. Methods to identify the strong wind episodes and the resulting self‐organizing map are both evaluated in‐part by two case studies where strong winds are known to have excited a basin‐scale baroclinic response in Quesnel Lake. [ABSTRACT FROM AUTHOR]

This study quantifies the contribution of atmospheric rivers (ARs) to annual and extreme river runoff and evaluates the relationships between watershed characteristics and AR-related maximum river runoff across British Columbia and southeastern Alaska (BCSAK). Datasets used include gauged runoff from 168 unregulated watersheds, topographic characteristics of those watersheds, a regionalARcatalog, and integrated vapor transport fields for water years (WYs) 1979-2016. ARs contribute ;22% of annual river runoff along the Coast and Insular Mountains watersheds, which decreases inland to ;11% in the watersheds of the Interior Mountains and Plateau. Average association between ARs and annual maximum river runoff attains .80%, .50%, and ,50% along the watersheds of the western flanks of the Coast Mountains, the Interior Mountains, and Interior Plateau, respectively. There is no significant change in AR-related extreme annual maximum runoff across BCSAK during 1979-2016. AR conditions occur during 25 out of 32 of the flood-related natural disasters in British Columbia duringWYs 1979-2016. AR-related annual maximum runoff magnitude is significantly higher than non-AR-related annual maximum runoff for 30% of the watersheds studied. Smaller and steeper watersheds closer to the coast are more susceptible to AR-related annual maximum runoff than their inland counterparts. These results illustrate the importance ofARactivity as a major control for the distribution of peak runoff in BCSAK. This work provides insights on the hydrological response of watersheds of northwestern North America to landfalling ARs that may improve flood risk assessment and disaster management in this region. [ABSTRACT FROM AUTHOR]

Background: Traditional food systems are under pressure from various stressors, including climate change which is projected to negatively alter the abundance of marine species harvested by coastal First Nations (FNs) in British Columbia (BC). Objective: To model the potential impacts of the climate-related declines in seafood production on the nutritional status of coastal BC FNs. In addition, we projected potential changes in nutrient intakes, under different scenarios of substitution where traditional seafood is replaced with alternative non-traditional foods. Methods: The study design is a mixed-method approach that combines two datasets: projected scenarios of climate-related change on seafood catch potential for coastal BC FNs and data derived from the cross-sectional First Nations Food, Nutrition, and Environment Study. The consumption of seafood was estimated using a food frequency questionnaire among 356 FNs. The contribution of seafood consumption to protein, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamins (A, B12, D, niacin), and minerals (zinc, selenium and iron) requirements was assessed using Dietary Reference Intakes (DRIs). Results: Traditional seafood consumption provided daily recommendations of EPA+DHA (74–184%) and vitamin B12 (84–152%) and substantial levels of niacin (28–55%), selenium (29–55%), vitamin D (15–30%) and protein (14–30%). Projected climate change was estimated to reduce the intakes of essential nutrients by 21% and 31% under ‘strong mitigation’ (Representative Concentration Pathway, RCP2.6) and ‘business-as-usual’ (RCP8.5) climate change scenarios, respectively, by the year 2050 relative to 2000. The hypothetical substitution of seafood with selected alternative non-traditional foods does not provide adequate amounts of nutrients. Conclusion: Traditionally-harvested seafood remains fundamental to the contemporary diet and health of coastal BC FNs. Potential dietary shifts aggravated by climate-related declines in seafood consumption may have significant nutritional and health implications for BC FN. Strategies to improve access to seafood harvest potential in coastal communities are needed to ensure nutritional health and overall well-being and to promote food security and food sovereignty in coastal FNs. [ABSTRACT FROM AUTHOR]

Weather-station data coverage, quality, and completeness across British Columbia, Canada, degrade outside of population centers and as one goes back in time. This data paucity motivates the search for the best reanalysis to serve as a climatological reference dataset. This study focuses on how well reanalyses represent 2-m temperature (T2M). Systematic error, random error, and two-sample Kolmogorov- Smirnov statistics of daily maximum and minimum T2M are evaluated from the European Centre for Medium-Range Weather Forecasts interim reanalysis (ERA-Interim), the Climate Forecast System Reanalysis (CFSR), the Japanese 55-year Reanalysis (JRA-55), and the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). Also evaluated are the 2- and 30-yr return levels of T2M, which are estimated by the method of L moments from a fitted generalized extreme value (GEV) distribution. Reanalyses are compared with observations from 57 meteorological stations distributed over the complex terrain of British Columbia from 1980 to 2010. Minimum temperatures are better captured than maximum temperatures by all four reanalyses. JRA-55 and ERA-Interim generally perform better across all metrics. Biases are largely explained by poor reanalysis terrain representation. Statistical stationarity over the 30-yr period is assessed by using Gaussian and GEV distributions fitted with and without time-dependent parameters. It is determined that stationary distributions are sufficient to represent the climate of T2M for this region and time period. [ABSTRACT FROM AUTHOR]

This study examines spatially variable stand structure and fire-climate relationships at a low elevation forest-grassland ecotone in west central British Columbia, Canada. Fire history reconstructions were based on samples from 92 fire-scarred trees and stand demography from 27 plots collected over an area of about 7 km2. We documented historical chronologies of widespread fires and localized grassland fires between AD 1600 and 1900. Relationships between fire events, reconstructed values of the Palmer Drought Severity Index, and annual precipitation were examined using superposed epoch and bivariate event analyses. Widespread fires occurred during warm, dry years and were preceded by multiple anomalously dry, warm years. Localized fires that affected only grassland-proximal forests were more frequent than widespread fires. These localized fires showed a lagged, positive relationship with wetter conditions. The landscape pattern of forest structure provided further evidence of complex fire activity with multiple plots shown to have experienced low-, mixed-, and/or high-severity fires over the last four centuries. We concluded that this forest-grassland ecotone was characterized by fires of mixed severity, dominated by frequent, low-severity fires punctuated by widespread fires of moderate to high severity. This landscape-level variability in fire-climate relationships and patterns in forest structure has important implications for fire and grassland management in west central British Columbia and similar environments elsewhere. Forest restoration techniques such as prescribed fire and thinning are oftentimes applied at the forest-grassland ecotone on the basis that historically high frequency, low-severity fires defined the character of past fire activity. This study provides forest managers and policy makers with important information on mixed-severity fire activity at a low elevation forest-grassland ecotone, a crucial prerequisite for the effective management of these complex ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Criminology & Criminal Justice is the property of University of Toronto Press 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.)

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.)

Classifications of atmospheric weather patterns (WPs) are widely used for the description of the climate of a given region and are employed for many applications, such as weather forecasting, downscaling of global circulation model outputs and reconstruction of past climates. WP classifications were recently used to improve the statistical characterisation of heavy rainfall. In this context, bottom-up approaches, combining spatial distribution of heavy rainfall observations and geopotential height fields have been used to define WP classifications relevant for heavy rainfall statistical analysis. The definition of WPs at the synoptic scale creates an interesting variable which could be used as a link between the global scale of climate signals and the local scale of precipitation station measurements. We introduce here a new WP classification centred on the British Columbia (BC) coastal region (Canada) and based on a bottom-up approach. Five contrasted WPs composed this classification, four rainy WPs and one non-rainy WP, the anticyclonic pattern. The four rainy WPs are mainly observed in the winter months (October to March), which is the period of heavy precipitation events in coastal BC and is thus consistent with the local climatology. The combination of this WP classification with the seasonal description of rainfall is shown to be useful for splitting observed precipitation series into more homogeneous sub-samples (i.e. sub-samples constituted by days having similar atmospheric circulation patterns) and thus identifying, for each station, the synoptic situations that generate the highest hazard in terms of heavy rainfall events. El Niño-Southern Oscillations (ENSO) significantly influence the frequency of occurrence of two coastal BC WPs. Within each WP, ENSO seem to influence only the frequency of rainy events and not the magnitudes of heavy rainfall events. Consequently, heavy rainfall estimations do not show significant evolution of heavy rainfall behaviour between Niño and Niña winters. However, the WP approach captures the variability of the probability of occurrences of synoptic situations generating heavy rainfall depending on ENSO and opening interesting perspectives for the analysis of heavy rainfall distribution in a non-stationary context. [ABSTRACT FROM AUTHOR]

The spatial resolution gap between global or regional climate models and the requirements for local impact studies motivates the need for climate downscaling. For impact studies that involve glacier modelling, the sparsity or complete absence of climate monitoring activities within the regions of interest presents a substantial additional challenge. Downscaling methods for this application must be independent of climate observations and cannot rely on tuning to station data. We present new, computationally-efficient methods for downscaling precipitation and temperature to the high spatial resolutions required to force mountain glacier models. Our precipitation downscaling is based on an existing linear theory for orographic precipitation, which we modify for large study regions by including moist air tracking. Temperature is downscaled using an interpolation scheme that reconstructs the vertical temperature structure to estimate surface temperatures from upper air data. Both methods are able to produce output on km to sub-km spatial resolution, yet do not require tuning to station measurements. By comparing our downscaled precipitation (1 km resolution) and temperature (200 m resolution) fields to station measurements in southern British Columbia, we evaluate their performance regionally and through the annual cycle. Precipitation is improved by as much as 30% (median relative error) over the input reanalysis data and temperature is reconstructed with a mean bias of 0.5°C at locations with high vertical relief. Both methods perform best in mountainous terrain, where glaciers tend to be concentrated. [ABSTRACT FROM AUTHOR]

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.)

Aim Limited population structure is predicted for vagile, generalist species, such as the grey wolf ( Canis lupus L.). Our aims were to study how genetic variability of grey wolves was distributed in an area comprising different habitats that lay within the potential dispersal range of an individual and to make inferences about the impact of ecology on population structure. Location British Columbia, Canada – which is characterized by a continuum of biogeoclimatic zones across which grey wolves are distributed – and adjacent areas in both Canada and Alaska, United States. Methods We obtained mitochondrial DNA control region sequences from grey wolves from across the province and integrated our genetic results with data on phenotype, behaviour and ecology (distance, habitat and prey composition). We also compared the genetic diversity and differentiation of British Columbia grey wolves with those of other North American wolf populations. Results We found strong genetic differentiation between adjacent populations of grey wolves from coastal and inland British Columbia. We show that the most likely factor explaining this differentiation is habitat discontinuity between the coastal and interior regions of British Columbia, as opposed to geographic distance or physical barriers to dispersal. We hypothesize that dispersing grey wolves select habitats similar to the one in which they were reared, and that this differentiation is maintained largely through behavioural mechanisms. Main conclusions The identification of strong genetic structure on a scale within the dispersing capabilities of an individual suggests that ecological factors are driving wolf differentiation in British Columbia. Coastal wolves are highly distinct and representative of a unique ecosystem, whereas inland British Columbia grey wolves are more similar to adjacent populations of wolves located in Alaska, Alberta and Northwest Territories. Given their unique ecological, morphological, behavioural and genetic characteristics, grey wolves of coastal British Columbia should be considered an Evolutionary Significant Unit (ESU) and, consequently, warrant special conservation status. If ecology can drive differentiation in a highly mobile generalist such as the grey wolf, ecology probably drives differentiation in many other species as well. [ABSTRACT FROM AUTHOR]

Holocene glacier fluctuations prior to the 'Little Ice Age' in Garibaldi Provincial Park in the British Columbia Coast Mountains were reconstructed from geomorphic mapping and radiocarbon ages on 37 samples of growth-position and detrital wood from glacier forefields. Glaciers in Garibaldi Park were smaller than at present in the early Holocene, although some evidence exists for minor, short-lived advances at this time. The first well-documented advance dates to 7700-7300 14C yr BP. Subsequent advances date to 6400-5100, 4300, 4100-2900 and 1600-1100 14C yr BP. Some glaciers approached their maximum Holocene limits several times during the past 10 000 years. Periods of advance in Garibaldi Park are broadly synchronous with advances elsewhere in the Canadian Cordillera, suggesting a common climatic cause. The Garibaldi Park glacier record is also broadly synchronous with the record of Holocene sunspot numbers, supporting previous research that suggests solar activity may be an important climate forcing mechanism. [ABSTRACT FROM AUTHOR]

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The intention of this research was to explore whether dendroclimatological relationships could be used to reconstruct long-term proxy records of 'Little Ice Age' glacier mass balance changes in the southern Coast Mountains of British Columbia. Tree-ring width chronologies from the Mt Waddington area were used in concert with historical glacier records to construct models spanning the past 450 years. The approach was to build models that were based on derived relationships between tree-ring growth and glacier mass balance: (1) warmer temperatures in the summer positively influence tree growth but are detrimental to glacier health; (2) colder temperatures during the winter and deeper snowpack have a negative impact on tree growth, whereas they are related to greater accumulation on the glacier during the winter season. Stepwise regression analyses were applied to tree-ring chronologies to predict glacier mass balance at local and regional scales. The models of net annual balance for the region (regional data set) show that periods of positive mass balance occurred in the AD 1750s, 1820s to 1830s and 1970s. Peaks of winter balance correspond closely to these periods, showing a sharp drop in winter mass balance towards the end of the nineteenth century. Wavelet analyses suggest that glacial mass balance regimes in the region respond synchronously to Pacific Ocean circulation systems such as the El Niño Southern Oscillation and the Pacific Decadal Oscillation. [ABSTRACT FROM AUTHOR]

Two independent reconstructions of maximum May-August temperatures are developed from a new network of Engelmann spruce tree-ring chronologies at treeline sites across Interior British Columbia (IBC). The IBC reconstruction (AD 1600-1997) uses the longest three ring-width (RW) and two maximum latewood density (MXD) chronologies from the region. The shorter (regional) reconstruction (REG, 1845-1997) is based on an independent, more broadly based network of chronologies (12 RW and 5 MXD) and verifies the regional signal in the parsimoniously sampled IBC reconstruction. Both models explain 53% of the regional temperature variance (1912-1995) and correlate strongly (r = 0.92) over their common period. The IBC reconstruction indicates two prolonged cooler intervals, c. 1620-1710 and 1775-1880, separated by warmer conditions that approached late twentieth-century normals between c. 1710 and 1730. The mean anomaly over the 1600-1900 period is estimated at 0.38°C below the 1961-1990 mean with the seventeenth century (1601-1700) being marginally colder than the nineteenth century (-0.53: -0.49°C). Both reconstructions model the rise in temperatures from the 1880s to 1940s and indicate that maximum summer temperatures since 1930 have been warmer than at any period since 1600. The IBC record from 1600-1900 is very similar to the mean summer-temperature record reconstructed in the adjacent Canadian Rockies, providing mutual verification for the regional nature of the signal in both reconstructions. This is the first maximum summer-temperature reconstruction from North America. Significant changes are also noted in the relationships between summer mean, maximum and minimum temperatures in this region in the last few decades with a greater absolute rate of increase in mean and minimum temperatures. These changing relationships suggest it is prudent to model tree-ring response to a variety of temperature parameters rather than using mean-temperature values. [ABSTRACT FROM AUTHOR]

Discusses Holocene vegetation and natural disturbance in the Englemann Spruce-Subalpine Fir (ESSF) biogeoclimatic zone at Mount Kobau, British Columbia. Reconstruction of the vegetation and natural disturbance history of the Mount Kobau area, in the Engelmann spruce (Picea engelmannii Parry ex Engelm.) ? subalpine fir (Abies lasiocarpa (Hook.) Nutt.) ESSF forest, using pollen, plant macrofossils, and microscopic charcoal; Description of Holocene period of rapid warming; Increase of moisture during the mid-Holocene when fires may have occurred more widely and burned more severely; How open lodgepole pine (Pinus contorta Dougl. ex Loud.) parkland occupied the mountain summit; Cooling of the Late-Holocene which resulted in the establishment of modern ESSF forest; Confirmation of a broad three-stage regional climate pattern inferred by the vegetation of the Holocene; Under future anticipated climate change, the high-elevation, dry ESSF forests in southern British Columbia may be replaced by grasslands.

(1) The effects of man and climate on fire frequency have been studied using historical data and a fire-history model in Glacier National Park in British Columbia, Canada. (2) Glacier National Park experienced a change in fire cycle in the 1760s, which could be related to the occurrence of the Little Ice Age. Before 1760, the fire cycle was 80 years and after 1760 it was 110 years. The longer fire cycle after 1760 was clearly related to the cooler, meister climate which also resulted in the advance of glaciers at that time in the Park. (3) The construction of the Canadian Pacific Railroad through the Park corresponded to a period in which the area burnt by man increased (1883, 1885 and 1886)and many lightning fires occurred. There has not been a decrease in the fire frequency since the establishment of Glacier National Park in 1888, despite a fire-suppression policy. (4) Large, high-intensity, rapidly spreading fires caused by lightning are associated with a characteristic synoptic weather pattern which consists of two parts: (i) intense fuel drying associated with a stationary high-pressure system blocking access of moist Pacific air, and (ii) one or more periods of breakdown of the high-pressure system into low-pressure systems which create lightning and high winds. (5) To have supplanted climate as a major determinant of fire frequency, man must either have used regular management burning or suppressed fires during critical weather periods. Because this has not occurred in Glacier National Park, the present fire regime is largely natural. [ABSTRACT FROM AUTHOR]

An objective synoptic climatology of daily 500mb pressure patterns for the International Hydrological Decade (1965–1974) for southwestern Canada is presented. The climatological characteristics of the synoptic types are examined in terms of the natural glacier seasons of Sentinel Glacier, British Columbia. Although the number of years available for analysis is limited, a significant statistical relationship between the mass balance of Sentinel Glacier and the small-scale synoptic types is present. Glacier accumulation appears to be controlled mainly by the number of synoptic types associated with heavy precipitation that occur during the fall, winter, and spring. Summer melt is largely a function of the frequency of those synoptic-scale patterns bringing high temperatures and clear skies to the region. [ABSTRACT FROM AUTHOR]