Boreal Plains Ecozone Research Articles

Mapping the distance between fire hazard and disaster for communities in Canadian forests.

Communities interspersed throughout the Canadian wildland are threatened by fires that have become bigger and more frequent in some parts of the country in recent decades. Identifying the fireshed (source area) and pathways from which wildland fire may ignite and spread from the landscape to a community is crucial for risk-reduction strategy and planning. We used outputs from a fire simulation model, including fire polygons and rate of spread, to map firesheds, fire pathways and corridors and spread distances for 1980 communities in the forested areas of Canada. We found fireshed sizes are larger in the north, where the mean distances between ecumene and fireshed perimeters were greater than 10 km. The Rayleigh Z test indicated that simulated fires around a large proportion of communities show significant directional trends, and these trends are stronger in the Boreal Plains and Shields than in the Rocky Mountain area. The average distance from which fire, when spreading at the maximum simulated rate, could reach the community perimeter was approximately 5, 12 and 18 km in 1, 2 and 3 days, respectively. The average daily spread distances increased latitudinally, from south to north. Spread distances were the shortest in the Pacific Maritime, Atlantic Maritime and Boreal Plains Ecozones, implying lower rates of spread compared to the rest of the country. The fire corridors generated from random ignitions and from ignitions predicted from local fire history differ, indicating that factors other than fuel (e.g. fire weather, ignition pattern) play a significant role in determining the direction that fires burn into a community.

New aboveground biomass equations by components for small black spruce in peatland ecosystems of Western Canada

Black spruce is the most common tree species in Canada, dominating treed peatlands where they are usually stunted. We used 495 destructively sampled trees from 56 plots to develop allometric models of aboveground biomass by components (stem, branches, and needles) for small (<5 m tall) black spruce from peatlands in the Taiga Plains and Boreal Plains Ecozones of Western Canada, for which there were no specific models available of biomass by components. We used leave-one-plot-out cross-validation to assess transferability and compare our models with existing national and ecozone-specific equations. Our models predicted total tree biomass with better accuracy and less biased estimates than the national model (relative RMSE: 30% versus 35% national; relative bias: +1% versus –12% national). Similar results were obtained in other external datasets. Existing ecozone equations performed worse than either our models or the national ones. When we applied the models at the plot level to predict aboveground biomass density (Mg·ha−1), our models outperformed the national model again (relative RMSE: 15.9% versus 18.6% national, relative bias: +3.5% versus –13.6% national). These results indicate that at least for peatlands of Western Canada, our models provide better aboveground biomass estimates for small black spruce trees than existing models.

Variability of sedimentary phosphorus composition across Canadian lakes

Phosphorus (P) in lake sediments is stored within diverse forms, often associated with metals, minerals, and organic matter. Sediment P can be remobilized to the water column, but the environmental conditions influencing the P retention-release balance depend upon the sediment chemistry and forms of P present. Sequential fractionation approaches can be used to help understand forms of P present in the sediments, and their vulnerability to release. We assessed P composition in surficial sediments (as an assemblage of six P-fractions) and its relationship with watershed, and lake-specific explanatory variables from 236 lakes across Canada. Sediment P composition varied widely across the 12 sampled Canadian ecozones. The dominant P-fractions were the residual-P and the labile organic P, while the loosely bound P corresponded to the smallest proportion of sediment TP. Notable contrasts in sediment P composition were apparent across select regions – with the most significant differences between sediment P in lakes from the mid-West Canada region (Prairies and Boreal Plains ecozones) and both Eastern coastal (Atlantic Maritime and Atlantic Highlands) and Western coastal (Pacific Maritime) ecozones. The ecozone attributes most critical to sediment P speciation across Canadian lakes were related to soil types in the watershed (e.g., podzols, chernozems, and Luvisols) and the chemical composition of lake water and sediments, such as dissolved Ca in lake water, bulk sedimentary Ca, Al, and Fe, dissolved SO4 in lake water, lake pH, and salinity. Understanding predictors of the forms of P stored in surficial sediments helps advance our knowledge of in-lake P retention and remobilization processes across the millions of unstudied lakes and can help our understanding of controls on internal P loading.

Characterization of chanterelle (Cantharellus cibarius) and pine mushrooms (Tricholoma magnivelare) in northern Saskatchewan

Baseline data on the boreal jack pine associated chanterelle (Cantharellus cibarius Fr.) and pine mushrooms (Tricholoma magnivelare (Peck) Redhead) in the Boreal Plain Ecozone of Saskatchewan were collected in five ecosites of productive mushroom areas. It investigated hourly weather parameters correlated with daily purchase volumes over 4 yrs; yield data over 5 yrs; and varying age, tree density, and species for presence of mushrooms in over 100 stands. All plots fell within the lichen jack pine (jP) ecosite with an overstory entirely of jack pine. The understory was dominated by reindeer lichen, bearberry, and blueberry. Plots were well- to rapidly drained, subxeric to submesic, with low nutrient regime. Both chanterelle and pine mushrooms were present in jack pine stands of < 20 yrs, with greatest occurrence in pure jack pine stands of 41–60 yrs in moderately open A-B canopy density. Weekly purchase data correlated with environmental parameters. Growing degree days (GDD) (base temperature 5 °C) + soil temperature (minimum 500 ± 70 GDD), + either soil moisture or precipitation (cumulative 50–100 mm) provided the highest regression value with chanterelle yield 6–13 wks prior to first appearance. The 5-yr total chanterelle yield from this region averaged 7100 kg·yr−1. Chanterelle cap diameter was a good predictor of fresh weight and proxy for yield. Pine mushroom was < 10% of chanterelle yield, averaging 1.72 kg·ha−1over 4 yrs based on 5 days picking. With future climate predictions of warmer and moister conditions, timing of fruiting body appearance is anticipated to advance.

What controls fire spatial patterns? Predictability of fire characteristics in the Canadian boreal plains ecozone

AbstractMost regulatory and certification agencies in Canada now require forest management plans to include some level of historical fire pattern approximation. As a result, sustainable forest management and enhancements to existing fire management policies and practices require a thorough understanding of the spatial fire patterns created and maintained by fire as well as the environmental conditions when they occur. To date, however, no boreal fire pattern study has examined relationships between the spatial arrangement of fire patterns, including vegetation remnants, and its main environmental top‐down and bottom‐up controls, based on a large number of fire events across large areas of the Canadian boreal forest. In this study, we leverage a recent, comprehensive, Landsat‐derived fire pattern dataset that includes information on fire vegetation remnants for the Canadian boreal plains ecozone, covering 507 fires and 2.5 Mha, to characterize the predictability of six fire pattern metrics. We then compare these metrics to multiple top‐down (monthly climate) and bottom‐up (topography, fuels, natural barriers, and disturbance history) controls on fire behavior. To do so, we first reduced the fire pattern metrics to three principal components and used a random forest modeling approach to better understand the main environmental explanatory controls. Across this large number of fires, we identified three dimensions of fire patterns: compactness, or the complexity of the perimeter; patchiness, or the spatial heterogeneity in the burned patches; and residualness, or the amount of fire vegetation remnants within the burned patches. We found that patchiness was mostly conditioned by the land cover through variables characterizing the type and connectedness of the fuels; however, summer and spring drought were locally important. Compactness responded to a combination of the disturbance history, land cover, and summer drought. The presence of water resulted in less compact fires. Residualness was a function of the disturbance history, topography, and land cover. Fires in lower elevations presented the most variable patterns, in response to changes in the amount and types of fuel. This research offers an enhanced understanding of the hierarchical interactions between resulting fire patterns and environmental conditions that are critical to supporting management decisions.

Assessing Drivers of Cross-Scale Variability in Peat Smoldering Combustion Vulnerability in Forested Boreal Peatlands

Wildfire represents the largest areal disturbance of forested boreal peatlands and the spatial variability in the severity of these peat fires is both a leading source of uncertainty in boreal wildfire carbon emissions and a major challenge for regional wildfire management. Peat smouldering can emit large quantities of carbon and smoke to the atmosphere, and therefore can contribute to hazardous air quality. The wildland-industry interface and wildland-urban interface are both extensive across the sub-humid boreal plains (BP) ecozone where one-third of the area is covered by peatlands. As such, there is a growing research need to identify drivers of variability in smouldering combustion. This study uses hydrophysical peat properties to assess the drivers of cross-scale variability in peat smouldering combustion vulnerability in forested peatlands across the BP. Using a space-for-time chronosequence across the 120-year fire return interval and three main hydrogeological settings, and by incorporating hummock, hollow and margin locations, cross-scale variability is studied. We find that, based on peat properties such as specific yield (Sy) and gravimetric water content, forested peatland margins represent areas of high peat smouldering vulnerability, and that this is exacerbated with an increasing time-since-fire (stand-age). Although increasing Sy with time-since-fire in peatland middles may buffer water table drawdown, when accounting for increases in canopy fuel load, transpiration, and feather moss dominance forested peatland middles also become more vulnerable to smouldering combustion with time-since-fire. Moreover, the interaction of peatland margins with coarse- and heterogeneous-grained hydrogeological settings leads to lower Sy and higher density margin peat than in fine-grained settings, further increasing smouldering vulnerability. We estimate that forested peatland margins are vulnerable to combustion throughout their entire profile i.e. burn-out, under moderate-high water deficits in the BP. Furthermore, we identify peatland margin: total area ratio as a driver of smouldering vulnerability where small peatlands that are periodically disconnected from regional groundwater systems are the most vulnerable to high total peat carbon loss. We suggest that these drivers of cross-scale variability should be incorporated into peatland and wildfire management strategies, especially in areas near the wildland-industry and wildland-urban interface.

Controls on evapotranspiration from jack pine forests in the Boreal Plains Ecozone

AbstractThe exchanges of water, energy and carbon between the land surface and the atmosphere are tightly coupled, so that errors in simulating evapotranspiration lead to errors in simulating both the water and carbon balances. Areas with seasonally frozen soils present a particular challenge due to the snowmelt‐dominated hydrology and the impact of soil freezing on the soil hydraulic properties and plant root water uptake. Land surface schemes that have been applied in high latitudes often have reported problems with simulating the snowpack and runoff. Models applied at the Boreal Ecosystem Research and Monitoring Sites in central Saskatchewan have consistently over‐predicted evapotranspiration as compared with flux tower estimates. We assessed the performance of two Canadian land surface schemes (CLASS and CLASS‐CTEM) for simulating point‐scale evapotranspiration at an instrumented jack pine sandy upland site in the southern edge of the boreal forest in Saskatchewan, Canada. Consistent with past reported results, these models over‐predicted evapotranspiration, as compared with flux tower observations, but only in the spring period. Looking systematically at soil properties and vegetation characteristics, we found that the dominant control on evapotranspiration within these models was the canopy conductance. However, the problem of excessive spring ET could not be solved satisfactorily by changing the soil or vegetation parameters. The model overestimation of spring ET coincided with the overestimation of spring soil liquid water content. Improved algorithms for the infiltration of snowmelt into frozen soils and plant‐water uptake during the snowmelt and soil thaw periods may be key to addressing the biases in spring ET.

Hydrological functions of a peatland in a Boreal Plains catchment

AbstractStreamflow response in Boreal Plains catchments depends on hydrological connectivity between forested uplands, lakes, and peatlands, and their hydrogeomorphic setting. Expected future drying of the Boreal Plains ecozone is expected to reduce hydrological connectivity of landscape units. To better understand run‐off generation during dry periods, we determined whether peatland and groundwater connectivity can dampen expected future water deficits in forests and lakes. We studied Pine Fen Creek catchment in the Boreal Plains ecozone of central Saskatchewan, Canada, which has a large, valley‐bottom, terminally positioned peatland, two lakes, and forested uplands. A shorter intensive study permitted a more detailed partitioning of water inputs and outputs within the catchment during the low flow period, and an assessment of a 10‐year data set provided insight into the function of the peatland over a range of climate conditions. Using a water balance approach, we learned that two key processes regulate flow of Pine Fen Creek. The cumulative impact of landscape unit hydrological connectivity and the peatland's hydrological functional state were needed to understand catchment response. There was evidence of a run‐off threshold which, when crossed, changed the peatland's hydrological function from transmission to run‐off generation. Results also suggest the peatland should behave more often as a transmitter of groundwater than as a generator of run‐off under a drier climate future, owing to a reduced water supply.

Trapped river otters (Lontra canadensis) from central Saskatchewan differ in total and organic mercury concentrations by sex and geographic location

Mercury (Hg) in wildlife remains of great concern, especially for apex piscivores. Despite this, exposure information from many species in many areas is lacking, so that management decisions are hampered. Here we examine Hg concentrations in fur, liver, and kidney tissues from river otters ( Lontra canadensis (Schreber, 1777)) ( n = 203) to quantify existing Hg concentrations over a broad geographic area in Saskatchewan. Mean fur total Hg (THg) (9.68 ± 7.52 mg/kg fresh weight (f.w.)) was significantly correlated with THg and organic Hg (OHg) in liver and kidney tissue, showcasing the potential for using fur as a noninvasive method of monitoring Hg in top-level mammals. Livers of males had higher mean OHg concentrations than livers of females (males: 2.71 mg/kg d.w., females: 1.87 mg/kg d.w.), but not significantly so. No sex-related differences were observed in kidney OHg concentrations. THg concentrations in otter fur collected in the Boreal Shield ecozone (Churchill River Upland) were significantly higher (mean = 16.1 mg/kg f.w.) than in otter fur collected from the Boreal Plain ecozone (mean = 8.59 mg/kg f.w.). Fur from otters ( n = 20; trapping block N66) trapped near a decommissioned smelter contained the highest concentrations of THg in the study (mean = 18.4 mg/kg f.w.).

Bioclimatic assessment of abiotic factors affecting relative abundance and distribution of wheat stem sawfly (Hymenoptera: Cephidae) in western Canada

AbstractWheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), indigenous to North America, quickly adapted from host native grasses to wheat crops (Triticum Linnaeus (Poaceae)) with expansion of agriculture on the Great Plains of North America. Bioclimatic simulation tools, such as Climex, predict the potential geographic distribution and establishment of insects in ecosystems, based on climate. The ecoclimatic index, a measure of ecological suitability, integrates potential population growth with stresses to produce estimates of relative abundance. This simulation software was used to develop a bioclimate model for C. cinctus in western Canada. Results fostered a better understanding of how C. cinctus responded to selected climate variables. Two general circulation models were then applied to assess the response of C. cinctus populations to future climate. Relative to current climate, predicted changes in C. cinctus distribution and relative abundance were greatest for 2030, with a small further increase for 2070. Across the Prairies and Boreal Plains Ecozones, changes in ecoclimatic index were greater than in geographic distribution. Both general circulation models indicated most of this area would be categorised as very favourable. This suggests that the potential for pest populations could expand into areas that do not currently experience economic losses associated with C. cinctus.

Remote sensing of ecosystem trajectories as a proxy indicator for watershed water balance

AbstractEcosystem trajectories are inextricably linked to hydrology; however, water availability is not easily observed within the landscape. The response of vegetation to soil water availability may provide an indicator of local hydrology and the resilience or sensitivity of ecosystems to long‐term changes in water balance. In this study, vegetation trajectories derived from Landsat Modified Soil Adjusted Vegetation Index over a 22‐year period are used as an indicator of spatio‐temporal changes of watershed water balance and surface water storage within 6 proximal watersheds of the Boreal Plains ecozone of Alberta, Canada. The interactions between hydrology, topography, geology, and land cover type are examined as they relate to vegetation change.In this study, we find that run‐off ratio (run‐off/precipitation) is greater within watersheds with greater variability of relief, compared within subhumid, wetland‐dominated watersheds (average = 0.35, 0.20, respectively), which experience lagged run‐off response. A 2‐year drought had a greater impact on vegetation trajectories within variable relief watersheds containing a high proportion of coarse‐grain surficial geology, compared with peatland‐dominated watersheds. The drought extended for an additional 1 to 2 years within 3 subhumid watersheds, reducing watershed run‐off to less than 50 mm per water year (November to October) in 2 watersheds. However, proportional area of decline of Modified Soil Adjusted Vegetation Index was significantly less within these watersheds. The results of this study indicate that wetlands play an important role for local water balance and ecosystem maintenance during periods of water stress and should be considered within land use planning and reclamation strategies of the Boreal Plains.

Quantifying local fire regimes using the Landsat data-archive: a conceptual framework to derive detailed fire pattern metrics from pixel-level information

ABSTRACTFree and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe. Despite the availability and potential of these data, few studies have analysed residual vegetation patterns and/or partial mortality of fire across the Canadian boreal forest, and those available, are either incomplete or inaccurate. Further, they all differ in the methods and spatial language, which makes it difficult for managers to interpret fire patterns over large areas. There is an urgent need for methods to help unify fire pattern observations across the Canadian boreal forest. This study explores the capacity of the Landsat data archive when coupled with a recently developed fire mapping approach and a robust spatial language to characterize and compare tree mortality patterns across the boreal plains ecozone, Canada. With 507 fires 2.5 Mha mapped, this study represents the most comprehensive analysis of mortality patterns for study area. Summaries from this demonstration generated an accurate characterization of the fire patterns the various ecoregions based on seven key fire metrics. The comparison between ecoregions revealed differences in the amount of residual vegetation, which in turn suggested various climate, topography and/or vegetation ecosystem drivers.

Early nitrogen fertilization effects on 13 years of growth of 4 hybrid poplars in Saskatchewan, Canada

Published literature shows contrasting effects of fertilization in forest plantations. The objective of this study was to determine the effects of early Nitrogen (N) fertilization on the growth of four hybrid poplar clones (Katepwa, Hill, Okanese, Walker) at two contrasting sites in the Boreal Plains ecozone of Canada. Using ammonium nitrate fertilizer, three N fertilizer rates were applied annually for the first three growing seasons, 0 kg ha−1 of N (0N, control), 150 kg ha−1 of N (150 N) and 300 kg ha−1 of N (300 N). Tree growth measurements, soil nutrients, and foliar nutrients data were analyzed. Fertilization resulted in tree growth remaining unchanged, or decreasing significantly for some of the poplar clones, compared to the control. Mean stand volume (300 N plots across the four clones) at age 3 years was significantly lower than the control. However, there were no significant fertilization effects on stand volume at age 8 and 13 years, suggesting a short-term effect of fertilization. Stand volume yields (0N) at age 13 years were 104–128 (Katepwa), 58–83 (Hill), 57–82 (Okanese), and 56–85 m3 ha−1 (Walker). On average, stand survival was >90% for the Katepwa, Okanese, and Hill clones, but was much lower for the Walker clone, ranging from 44 to 56%. Fertilization resulted in significant increases of soil exchangeable NO3-N, but there were no significant changes in soil exchangeable NH4-N, extractable Phosphorus (P), or pH. A foliar nutrient vector analysis showed that fertilization resulted in excess amounts of all major foliar macronutrients (Ca, Mg, N, P, K), compared to the control, which could have a possible toxic or antagonistic effect on tree growth. Fertilization also had an effect on micronutrient uptake, by nearly doubling the foliar Manganese (Mn) concentrations at both sites, averaging 387 (Alfalfa site) and 127 mg kg−1 (Pasture site). The increased foliar Mn had a toxic effect on tree growth (Alfalfa) for three of the clones, Okanese and Walker being the most affected. The top yielding poplar clone was Katepwa (8.00–9.84 m3 ha−1 year−1, age 13 years), which was not affected by the increased Mn uptake, regardless of soil pH levels. This study showed that hybrid poplar clones can be used for successful plantation establishment in the Boreal Plains without the need for any fertilization, which is very promising for the forest products industry of Canada.

Bioclimatic approach to assessing factors influencing shifts in geographic distribution and relative abundance of two flea beetle species (Coleoptera: Chrysomelidae) in North America

AbstractCrucifer flea beetle, Phyllotreta cruciferae (Goeze) and striped flea beetle, Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae) are the most chronic and economically important flea beetle pests of cruciferous (Brassicaceae) crops in western Canada. There have been reports that populations of P. striolata are increasing in numbers and expanding their geographic range. Climate is the fundamental factor regulating the distribution and abundance of most insect species. Bioclimate simulation models of the two flea beetle species were developed to assess climatic factors influencing shifts in their geographic distribution and density. The results fostered a better understanding of how the two species responded to selected climate variables. Growing seasons with above average precipitation were predicted to favour the geographic distribution of P. striolata more than P. cruciferae. Both P. cruciferae and P. striolata were sensitive to temperature changes in the range of −2 °C to +2 °C. The ecoclimatic index (suitability index) for P. cruciferae increased with increasing temperatures, whereas the index for P. striolata declined with increasing temperatures. This study highlights the regions of the Prairies and Boreal Plains Ecozones that are most sensitive to shifts of the two populations and which may require changes in insecticidal seed treatments for effective control.

Life‐cycle assessment of torrefied coppice willow co‐firing with lignite coal in an existing pulverized coal boiler

AbstractCoal‐fired electricity generation is a major emitter of greenhouse gases (GHGs) in Canada and the Federal Government has taken steps toward mandated reduction in GHG emissions. One pathway to reduced emissions is via co‐firing of coal with short‐rotation coppice (SRC) willow grown on marginal land in Saskatchewan. This study uses a life‐cycle inventory model to investigate the GHG emissions from nine scenarios for electricity generation with willow pellets at a retrofitted generating station in Saskatchewan. Torrefied and non‐torrefied willow pellets from SRC plantations in the Prairie and Boreal Plains ecozones are considered. Direct co‐firing of pellets and indirect co‐firing via a circulating fluidized bed gasifier are modeled. The model output shows cumulative, levelized, and disaggregated GHG emissions. The scenarios account for the plantation establishment period required to reach a co‐firing ratio of 40% by energy input. Torrefied and non‐torrefied willow pellets grown in the Prairie ecozone indirectly co‐fired with lignite coal result in 43% and 47% net cumulative GHG emissions reduction compared to the existing coal fired pathway. Direct co‐firing of the same feedstocks results in a 34% and 31% reduction in GHG emissions, respectively. The biomass‐based portion of all scenarios was found to produce negative net cumulative GHG emissions on a life‐cycle basis with willow grown in the Prairies ecozone (i.e., GHG emissions from the willow plantation to the combustion of the pellet with coal). Co‐firing is therefore a viable option for reducing GHG emissions from electricity generation. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd

Assessing post-industrial land cover change at the Pine Point Mine, NWT, Canada using multi-temporal Landsat analysis and landscape metrics

This study investigates land cover change near the abandoned Pine Point Mine in Canada's Northwest Territories. Industrial mineral development transforms local environments, and the effects of such disturbances are often long-lasting, particularly in subarctic, boreal environments where vegetation conversion can take decades. Located in the Boreal Plains Ecozone, the Pine Point Mine was an extensive open pit operation that underwent little reclamation when it shut down in 1988. We apply remote sensing and landscape ecology methods to quantify land cover change in the 20years following the mine's closure. Using a time series of near-anniversary Landsat images, we performed a supervised classification to differentiate seven land cover classes. We used raster algebra and landscape metrics to track changes in land cover composition and configuration in the 20years since the mine shut down. We compared our results with a site in Wood Buffalo National Park that was never subjected to extensive anthropogenic disturbance. This space-for-time substitution provided an analog for how the ecosystem in the Pine Point region might have developed in the absence of industrial mineral development. We found that the dense conifer class was dominant in the park and exhibited larger and more contiguous patches than at the mine site. Bare land at the mine site showed little conversion through time. While the combination of raster algebra and landscape metrics allowed us to track broad changes in land cover composition and configuration, improved access to affordable, high-resolution imagery is necessary to effectively monitor land cover dynamics at abandoned mines.

Estimating the spatial distribution and locating hotspots of forest biomass from harvest residues and fire-damaged stands in Canada's managed forests

Strategies for increasing the mobilization of forest biomass supply chains for bioenergy production require continuous assessments of the spatial and temporal availability of biomass feedstock. Using remote sensing products at a 250-m pixel resolution, estimates of theoretical biomass availability from harvest residues and fire-killed trees were computed by combining Canada-wide maps of forest attributes (2001) and of yearly (2002–2011) fires and harvests. At the national scale, biomass availability was estimated at 47 ± 18 M ODT year−1 from fire-killed trees and at 14 ± 2 M ODT year−1 from harvest residues. Mean biomass densities in burned and harvested pixels were estimated at 34 ± 3.0 ODT ha−1 and at 24 ± 1.2 ODT ha−1, respectively. Mean biomass densities also varied dramatically among ecozones, from 14 ODT ha−1 to 206 ODT ha−1 and from 6 ODT ha−1 to 63 ODT ha−1 for burned and harvested pixels, respectively. Spatial averaging with a 100-km radius window shows distinct hotspots of biomass availability across Canada. The largest hotspots from fire-killed trees reached 3.6 M ODT year−1 in the Boreal Shield and the Boreal Plains ecozones of northern Alberta and Saskatchewan, where fires are large and frequent. The largest hotspots from harvest residues reached 1.2 M ODT year−1 in the Montane Cordillera ecozone of British Columbia. The use of spatially explicit remote sensing products yields estimates of theoretical biomass availability that are methodologically consistent across Canada. Future development should include validations with on-the-ground forest inventories as well as the factoring in of environmental, technical and economic considerations to implement operational biomass supply chains.

Climate, location, and growth relationships with wood stiffness at the site, tree, and ring levels in white spruce (Picea glauca) in the Boreal Plains ecozone

We examined modulus of elasticity (MoE) derived from SilviScan in white spruce (Picea glauca (Moench) Voss) at the site, tree, and ring levels across the Boreal Plains ecozone in Canada. Area-weighted averages of MoE were calculated for juvenile and mature wood and were examined in relation to radial growth, climate, and location. Correlations indicated that there was a negative relationship between radial growth and MoE in the juvenile wood that was detectable at the site and tree levels; however, the relationship weakened in the mature wood, particularly at the site level. Few climate variables were correlated with MoE in juvenile wood, whereas multiple summer and fall climate variables showed a significant correlation with MOE in mature wood. A model describing the radial profile of MoE explained 58% of the variability in MoE, with 10% of the random variability attributed to between-tree differences. Elevation and summer water balance accounted for nearly all of the between-site variability. A decrease in MoE with increasing elevation was noted and has been previously linked to a decrease in cell wall thickness due to a shorter growing season at higher elevations. Integration of the MoE profile model into an individual-tree growth and yield simulator is the next logical step.

Utikuma Region Study Area (URSA) – Part 1: Hydrogeological and ecohydrological studies (HEAD)

The Utikuma Region Study Area (URSA) was initiated to develop spatially explicit modelling tools to predict the cumulative impacts of land use and natural disturbance on the Boreal Plains (BP) ecozone of the Western Boreal Forest. Research comprised several multi-year projects, spanning wet and dry climate periods that combined intensive detailed process studies at seven watersheds with extensive long-term ecohydrological and hydrogeological studies conducted across a 60-km transect representing the range of glaciated landforms characteristic of the sub-humid boreal forest in Alberta. These studies have improved our conceptual understanding and capacity to numerically model how climate and geology influence water and energy flow, and the hydrologic linkages and natural variability of the key processes influencing BP ecosystems. Eco-hydrogeological frameworks have been developed for designing, conducting, interpreting, and extrapolating research results for watershed management and construction across the Boreal Plain ecozone.

The changing water cycle: the Boreal Plains ecozone of Western Canada

The Boreal Plains Ecozone (BPE) in Western Canada is expected to be an area of maximum ecological sensitivity in the 21st century. Successful climate adaptation and sustainable forest management require a better understanding of the interactions between hydrology, climate, and vegetation. This paper provides a perspective on the changing water cycle in the BPE from an interdisciplinary team of researchers, seeking to identify the critical knowledge gaps. Our review suggests the BPE will likely become drier and undergo more frequent disturbance and shifts in vegetation. The forest will contract to the north, though the southern boundary of the ecotone will remain in place. We expect detrimental impacts on carbon sequestration, water quality, wildlife, and water supplies. Ecosystem interactions are complex, and many processes are affected differently by warming and drying, thus the degree and direction of change is often uncertain. However, in the short term at least, human activities are the dominant source of change and are unpredictable but likely decisive. Current climate, hydrological, and ecological monitoring in the BPE are limited and inadequate to understand and predict the complex responses of the BPE to human activities and climate change. This paper provides a case study of how hydrological processes critically determine ecosystem functioning, and how our ability to predict system response is limited by our ability to predict changing hydrology. WIREs Water 2015, 2:505–521. doi: 10.1002/wat2.1098This article is categorized under: Water and Life > Stresses and Pressures on Ecosystems Science of Water > Water and Environmental Change