Search

In anticipation of growing wildfire management challenges, the Canadian government is investing in WildFireSat, an Earth observation satellite mission designed to collect data in support of Canadian wildfire management. Although costs of the mission can be reasonably estimated, the benefits of such an investment are unknown. Here we forecast the possible benefits of WildFireSat via an avoided cost approach. We consider five socio-economic components: suppression costs (fixed and variable), timber losses, property, asset and infrastructure losses, evacuation costs, and smoke related health costs. Using a Monte Carlo analysis, we evaluated a range of possible changes to these components based on expert opinions. The resulting Net Present Value (NPV) estimates depend on the presumed impact of using WildFireSat decision support data products, with pessimistic and conservative assumptions generating mission costs that typically exceed potential benefits by 1.16 to 1.59 times, while more optimistic assumptions generate benefits in excess of costs by 8.72 to 10.48 times. The analysis here excludes some possibly significant market and non-market impacts expected from WildFireSat due to data limitations; accounting for these additional impacts would likely generate positive NPVs under even cautious impact assumptions. [ABSTRACT FROM AUTHOR]

Forest planting events present key opportunities to enhance forest adaptation and growth through the selection of appropriate growing materials (seeds and seedlings). Critical to such efforts is knowledge of the climatic distance that seed sources can be moved before significant growth forfeitures are incurred. These limits, referred to here as critical seed transfer distances (CSTD), can be used to identify a potential seed procurement region for any given planting site and can readily incorporate climate change projections.We assembled provenance trial data from a variety of sources and employed transfer functions to derive CSTDs for five major tree species in eastern North America.Optimal height growth at test sites was associated with modest warm‐to‐cold (i.e. northward) seed transfers of 1.6°C on average. Calculated transfer limits were large, indicating that seed sources could be moved significant climatic distances before height growth was less than 90% relative to that of the local seed source. These broad relationships, which were relatively consistent across species, would allow considerable flexibility in resulting seed transfer systems; however, given the significant uncertainty surrounding climate change—particularly in the location and timing of extreme weather events—prudent application of seed transfer limits may be appropriate.Synthesis: We assembled and analysed a significant amount of provenance data to derive novel information on seed movement limits for five tree species in eastern North America. This information will support forest managers in ongoing efforts to incorporate climate change into forest regeneration operations. [ABSTRACT FROM AUTHOR]

This study presents spatial models (i.e., thin-plate spatially continuous spline surfaces) of adjusted precipitation for Canada at daily, pentad (5 day), and monthly time scales from 1900 to 2015. The input data include manual observations from 3346 stations that were adjusted previously to correct for snow water equivalent (SWE) conversion and various gauge-related issues. In addition to the 42 331 models for daily total precipitation and 1392 monthly total precipitation models, 8395 pentad models were developed for the first time, depicting mean precipitation for 73 pentads annually. For much of Canada, mapped precipitation values from this study were higher than those from the corresponding unadjusted models (i.e., models fitted to the unadjusted data), reflecting predominantly the effects of the adjustments to the input data. Error estimates compared favorably to the corresponding unadjusted models. For example, root generalized cross-validation (GCV) estimate (a measure of predictive error) at the daily time scale was 3.6 mm on average for the 1960–2003 period as compared with 3.7 mm for the unadjusted models over the same period. There was a dry bias in the predictions relative to recorded values of between 1% and 6.7% of the average precipitations amounts for all time scales. Mean absolute predictive errors of the daily, pentad, and monthly models were 2.5 mm (52.7%), 0.9 mm (37.4%), and 11.2 mm (19.3%), respectively. In general, the model skill was closely tied to the density of the station network. The current adjusted models are available in grid form at ~2–10-km resolutions. [ABSTRACT FROM AUTHOR]

Policy makers and investors often need to consider trade-offs between alternative biomass-based energy supply options. Supply cost potentials for three bioenergy feedstocks prevalent in Canada including agricultural residues, dedicated woody crops, and forest harvest residues are summarized. Each feedstock has its own particular cost characteristics depending on the quantities involved. Importantly, this synthesis revealed significant differences in the uncertainty associated with the cost estimates, with agricultural residues having the greatest variation, followed by woody crops and postharvest forest residues, respectively. One implication of this uncertainty is that the attractiveness of each feedstock option likely depends on local market demand conditions and producer circumstances, making definitive aggregate supply estimates challenging. [ABSTRACT FROM AUTHOR]

The burning of wood for bioenergy produces significant amounts of ash residue that requires disposal. We constructed a cost model to evaluate the unit costs of three ash disposal methods in the Canadian context: landfills owned and operated by the bioenergy facility, municipal landfills, and forest site application. The model accounts for costs related to the pretreatment, transportation, and disposal of ash at a landfill or forest site. Model parameter values were assigned appropriate distributions (based on published literature and industry surveys), and Monte Carlo simulations were employed to produce a range of model outputs for each disposal option. Results indicate that existing landfills (if available for ash disposal) are likely the most cost-effective option (median value of $77 per tonne), although applying ash to a forest site is only ∼15%-20% more costly (median value of $92 per tonne). Indeed, the unit cost estimates across disposal options have considerable overlap. This suggests that close examination of firm-specific circumstances is highly warranted when choosing a disposal approach, even in the absence of accounting for potential environmental benefits associated with forest site disposal of ash. [ABSTRACT FROM AUTHOR]

Climate-influenced changes in fire regimes in northern temperate and boreal regions will have both ecological and economic ramifications. We examine possible future wildfire area burned and suppression costs using a recently compiled historical (i.e., 1980–2009) fire management cost database for Canada and several Intergovernmental Panel on Climate Change (IPCC) climate projections. Area burned was modelled as a function of a climate moisture index (CMI), and fire suppression costs then estimated as a function of area burned. Future estimates of area burned were generated from projections of the CMI under two emissions pathways for four General Circulation Models (GCMs); these estimates were constrained to ecologically reasonable values by incorporating a minimum fire return interval of 20 years. Total average annual national fire management costs are projected to increase to just under $1 billion (a 60% real increase from the 1980–2009 period) under the low greenhouse gas emissions pathway and $1.4 billion (119% real increase from the base period) under the high emissions pathway by the end of the century. For many provinces, annual costs that are currently considered extreme (i.e., occur once every ten years) are projected to become commonplace (i.e., occur once every two years or more often) as the century progresses. It is highly likely that evaluations of current wildland fire management paradigms will be necessary to avoid drastic and untenable cost increases as the century progresses. [ABSTRACT FROM AUTHOR]

Graphical Abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

We present a model that maps the net present value (NPV) associated with planting black spruce ( Picea mariana (Mill.) Britton, Sterns & Poggenb.) and white pine ( Pinus strobus L.) seed sources across a study area centred on Ontario, Canada. The model accounts for climate change through the use of universal response functions, which (in principle) predict the growth of any seed source under any climatic conditions. We demonstrated the use of the model for two locations in northern Ontario; both species exhibited significant variation in NPV across the study area and significant gains associated with climate-smart seed movements. For example, the NPV associated with potential white pine seed sources varied by more than $1500·ha−1 for a planting site at North Bay, Ontario. We also compared the NPV maps with climate similarity maps to examine the degree to which simple climate matching can act as a proxy for the detailed genecology relationships contained in the universal response functions. Overall, the climate similarity maps were well-correlated with the NPV maps; however, there was poor agreement regarding white pine seed deployment from North Bay, for which the two approaches identified opposite seed transfer directions. We propose that this situation can arise when species show strong adaptation to a central climatic optimum. [ABSTRACT FROM AUTHOR]

This study produced annual spatial models (or grids) of 27 growing-season variables for Canada that span two centuries (1901-2100). Temporal gaps in the availability of daily climate data-the typical and preferred source for calculating growing-season variables-necessitated the use of two approaches for generating these growing-season grids. The first approach, used only for the 1950-2010 period, employed a computer script to directly calculate the suite of growing-season variables from existing daily climate grids. Since daily grids were not available for the remaining years, a second approach, which employed a machine-learning method called boosted regression trees (BRT), was used to generate statistical models that related each growing-season variable to a suite of climate and water-related predictors. These BRT models were used to generate grids of growing-season variables for each year of the study period, including the 1950-2010 period to allow comparison between the two approaches. Mean absolute errors associated with the BRT-based grids were approximately 30% higher than those associated with the daily-based grids. The two approaches were also compared by calculating trends in growing-season length over the 1950-2010 period. Significant increases in growing-season length were obtained for nearly all ecozones across Canada, and there were no significant differences in the trends obtained from the two approaches. Although the daily-based approach tended to have lower errors, the BRT approach produced comparable map products that should be valuable for periods and regions for which daily data are not available. [ABSTRACT FROM AUTHOR]

This study estimates the potential physical amounts and financial costs of post-harvest forest residue biomass supply in Canada. The analyses incorporate the locations of harvest activities in Canada, the geographical variation of forest productivity patterns and the costs associated with the extraction and transportation of residue feedstock to bioenergy facilities. We estimated the availability of harvest residues within the extent of industrial forest management operations in Canadian forests. Our analyses focused on the extraction of biomass from roadside harvest residues that involve four major cost components: pre-piling and aggregation, loading, chipping and transportation. The estimates of residue extraction costs also included representation of basic ecological sustainability and technical accessibility constraints. Annual supply of harvestable residual biomass with these ecological sustainability constraints were estimated to be approximately 19.2–23.3 Tg * year −1 and 16.5–20.0 Tg * year −1 in scenarios that included both ecological and technical accessibility limitations. These estimates appear to be less than other similar studies, due to the higher level of spatial details on inventories and ecological and operational constraints in our analyses. The amount of residual biomass available in baseline scenarios at a supply cost of $60 ODT −1 and $80 ODT −1 were 1.08 and 1.38 Tg year −1 and 7.82 and 10.14 Tg year −1 respectively. Decreasing residue extraction costs by 35% increased the amount of residues available at a $60 ODT −1 and $80 ODT −1 supply price by ∼5.5–5.7 and ∼1.5–1.6 times respectively. The assessment methodology is generic and could be extended to examine residue supplies for specialized biomass markets such as lignocellulosic ethanol production. [ABSTRACT FROM AUTHOR]

Abstract: Short rotation woody crops (SRWC) have not been widely adopted as a viable feedstock for bioenergy production. We discuss three major information needs for R&D Managers improving adoption prospects for SRWC: (1) Understand how R&D affects the economics of SRWC – particularly “unit costs” of production; (2) Prices and trends for energy and environmental improvement and how these compare to SRWC costs; (3) Integrated biological and economic models. To enhance adoption prospects for SRWC R&D Managers should seek to lower unit costs to make these types of plantations more competitive with other energy alternatives. If non-market values are used as an argument to justify SRWC R&D investments managers still need to address adoption impediments. Even if non-market values are significant, adoption is required for society to realize benefits. We also argue that bioeconomic models can help identify needs, opportunities and challenges and illustrate some of these principles with an empirical example from Canada. [Copyright &y& Elsevier]

We present 50-year updates for two plant hardiness models (maps), developed originally by Agriculture Canada and the US Department of Agriculture (USDA), that are widely used for plant selection decisions in Canada. The updated maps show clear northward shifts in hardiness zones across western Canada. Shifts are less dramatic in southeastern Canada, with modest increases in zone values associated with the Canadian map but modest declines associated with the USDA approach. Species-specific climate envelope models are an alternative to generalized hardiness zones. We generated climate envelopes for 62 northern tree species over the same 50-year interval and found an average northward shift of 57 kilometers. These changes signal an increase in the productivity and diversity of plants that can be grown in Canada. However, late spring frosts and other factors discussed herein may limit the extent to which this potential is realized. [ABSTRACT FROM AUTHOR]

Assisted migration (AM) is often presented as a strategy to save species that are imminently threatened by rapid climate change. This conception of AM, which has generated considerable controversy, typically proposes the movement of narrowly distributed, threatened species to suitable sites beyond their current range limits. However, existing North American forestry operations present an opportunity to practice AM on a larger scale, across millions of hectares, with a focus on moving populations of widely distributed, nonthreatened tree species within their current range limits. Despite these differences (and many others detailed herein), these two conceptions of AM have not been clearly distinguished in the literature, which has added confusion to recent dialogue and debate. Here, we aim to facilitate clearer communication on this topic by detailing this distinction and encouraging a more nuanced view of AM. [ABSTRACT FROM AUTHOR]

The article highlights an economic model which aims to assist users in deciding the fate of ash trees threatened by the arrival of emerald ash borer (EAB) in North America from Asia. The model tracks the costs and benefits of treating or removing and then replacing a tree. To utilize the model, users such as homeowners, consulting foresters and arborists should first identify the size and location of the tree, as well as the type and planned location of the replacement tree.

The article discusses a study on the estimates of the potential cost of emerald ash borer or Agrilus planipennis Faimaire, in Canadian urban areas. The areas were identified through a digital version of Canada's urban areas cartographic boundary file. As an additional focus, probable effects to backyard trees were included. The types of costs that were integrated into the study are removal costs, replacement costs, treatment costs, and community overhead costs.

Over the past two decades, researchers at Natural Resources Canada's Canadian Forest Service, in collaboration with the Australian National University (ANU), Environment Canada (EC), and the National Oceanic and Atmospheric Administration (NOAA), have made a concerted effort to produce spatial climate products (i.e., spatial models and grids) covering both Canada and the United States for a wide variety of climate variables and time steps (from monthly to daily), and across a range of spatial resolutions. Here we outline the method used to generate the spatial models, detail the array of products available and how they may be accessed, briefly describe some of the usage and impact of the models, and discuss anticipated further developments. Our initial motivation in developing these models was to support forestry-related applications. They have since been utilized by a wider range of agencies and researchers. This article is intended to further raise awareness of the strengths and weaknesses of these climate models and to facilitate their wider application. [ABSTRACT FROM AUTHOR]

Global climate models are constantly being upgraded, but it is often not clear what these changes have on climate change impact projections. We used difference maps to directly compare downscaled projections of temperature and precipitation across North America for two versions (or generations) of three different Atmospheric-Ocean General Circulation Models (AOGCM)s. We found that AOGCM versions differed in their projections for the end of the current century by up to 4 °C for annual mean temperature and 60% for annual precipitation. To place these changes in an ecological context, we reanalyzed our work on shifts in tree climate envelopes (CEs) using the newer-generation AOGCM projections. Based on the updated AOGCMs, by the 2071-2100 period, tree CEs shifted up to 2.4 degrees further north or 2.6 degrees further south (depending on the AOGCM) and were about 10% larger in size. Despite considerable differences between versions of a given AOGCM, projections made by the newer version of each AOGCM were in general agreement, suggesting convergence across the three models studied here. Assessing the AOGCM outputs in this way provides insight into the magnitude and importance of change associated with AOGCM upgrades as they continue to evolve through time. [ABSTRACT FROM AUTHOR]

On 1 July 1961, the climatological day was redefined to end at 0600 UTC at all principal climate stations in Canada. Prior to that, the climatological day at principal stations ended at 1200 UTC for maximum temperature and precipitation and 0000 UTC for minimum temperature and was similar to the climatological day at ordinary stations. Hutchinson et al. reported occasional larger-than-expected residuals at 50 withheld stations when the Australian National University Spline (ANUSPLIN) interpolation scheme was applied to daily data for 1961-2003, and it was suggested that these larger residuals were in part due to the existence of different climatological days. In this study, daily minimum and maximum temperatures at principal stations were estimated using hourly temperatures for the same climatological day as local ordinary climate stations for the period 1953-2007. Daily precipitation was estimated at principal stations using synoptic precipitation data for the climatological day ending at 1200 UTC, which, for much of the country, was close to the time of the morning observation at ordinary climate stations. At withheld principal stations, the climatological-day adjustments led to the virtual elimination of large residuals in maximum and minimum temperature and a marked reduction in precipitation residuals. Across all 50 withheld stations the climatological day adjustments led to significant reductions, by around 12%% for daily maximum temperature, 15%% for daily minimum temperature, and 22%% for precipitation, in the residuals reported by Hutchinson et al. [ABSTRACT FROM AUTHOR]

We present the idea of using potential infringements on annual allowable harvest targets as an approach to estimate threats from invasive species to the forest products sector. The approach uses present-day harvest levels as a reference level to estimate when and where the impact of a nonnative forest pest could become economically damaging. We use a generic model that simulates spread and damage by nonnative invasive species, basic harvest and forest growth through time. The concept is illustrated with a case study of a new nonnative invasive pest, Sirex noctilio Fabricius on pine resources in eastern Canada. Impacts of invasion on wood supply, in particular, the point at which present-day harvest levels are not attainable, were identified for 77 non-overlapping geographical regions that delimit the primary wood supply areas around large mills and wood processing facilities in eastern Canada. The results identify the minimum area of a pest outbreak that could trigger harvest shortages (approximately 12.5–14 M ha of pine forests in Ontario and Quebec). Beyond this level, the amount of host resource available for harvesting in any given year declines rapidly. The failure to sustain broad-scale harvest targets may be an attractive and intuitive indicator for policy makers and regulators interested in developing control and “slow-the-spread” programs for non-native forest pests. [Copyright &y& Elsevier]

Abstract: This study explores the economic feasibility of fossil fuel substitution with biomass from short-rotation willow plantations as an option for greenhouse heating in southern Ontario, Canada. We assess the net displacement value of fossil fuel biomass combustion systems with an integrated purpose-grown biomass production enterprise. Key project parameters include greenhouse size, heating requirements, boiler capital costs and biomass establishment and management costs. Several metrics have been used to examine feasibility including net present value, internal rate of return, payback period, and the minimum or break-even prices for natural gas and heating oil for which the biomass substitution operations become financially attractive. Depending on certain key assumptions, internal rates of return ranged from 11–14% for displacing heating oil to 0–4% for displacing natural gas with woody biomass. The biomass heating projects have payback periods of 10 to >22 years for substituting heating oil and 18 to >22 years for replacing a natural gas. Sensitivity analyses indicate that fossil fuel price and efficiency of the boiler heating system are critical elements in the analyses and research on methods to improve growth and yield and reduce silviculture costs could have a large beneficial impact on the feasibility of this type of bioenergy enterprise. [ABSTRACT FROM AUTHOR]

In this paper we provide an overview of an integrated approach to modelling the risks and impacts associated with non-indigenous forest pest species. This is a broad and important topic given the scale of ecological and economic consequences associated with non-indigenous species in North America and elsewhere. Assessments of risks and impacts remain difficult due to complexities and interactions between the many factors driving invasions and outcomes. These processes occur across various spatial and temporal scales, and are often influenced and complicated by human activities. For each component of an ecological invasion (i.e., arrival, establishment, and spread), we review general approaches for modelling the phenomenon and identify data and knowledge gaps. With the greater availability of various spatial data and computational power we suggest the possibility of linking the models for each invasion component into a more integrated framework, thus allowing interactions and feedbacks between components to be better incorporated into risk modelling efforts. The approach is illustrated using examples from current work with Sirex noctilio Fabricius — a relatively new invasive wood wasp in eastern North America. [ABSTRACT FROM AUTHOR]

This study presents a model that assesses the potential impact of a new alien insect species, Sirex noctilio Fabricius, on pine timber supply and harvest activities in eastern Canada. We integrate the spread of S. noctilio with a broad-scale growth and harvest allocation model. Projections of pine mortality range between 25 × 106 and 115 × 106 m3 over 20 years depending on S. noctilio spread and impact assumptions. Our model suggests Ontario could experience the highest, most immediate losses (78% of the potential losses across eastern Canada), with Quebec sustaining most of the rest of the losses over the next 20 years. Potential losses of $86 to $254 million per year are simulated after 20 years. The net present value of total harvest losses after 28 years of outbreak ranges between $0.7 to $2.1 billion. Adaptation policies decrease short-term losses by 46%–55% and delay larger harvest failures by 9–11 years. Without harvest adaptation, failures to maintain annual allowable cut levels may occur once the total area infested exceeds 15 × 106 ha. While better understanding and representing S. noctilio behaviour will involve a significant effort, there is a strong demand by policy makers for this kind of information. [ABSTRACT FROM AUTHOR]

Abstract: Spatial models of global insolation and photovoltaic electricity generation potential for Canada were developed. The main objective was to provide Canadians with an easily accessible, reliable tool for rapidly estimating the monthly and yearly electricity production potential of grid-connected photovoltaic systems anywhere in the country, and for assessing the dependence of production on location, time of year and array orientation. Monthly mean daily insolation data from 144 meteorological stations across Canada were used, along with data from an additional eight stations in Alaska to improve the models in that region. Several photovoltaic array orientations were considered, including South-facing arrays with latitude and vertical tilts and a sun-tracking orientation. Partial thin plate smoothing splines as implemented in ANUSPLIN were used to generate the spatial insolation models. The models were based on geographic position and a transform of monthly mean precipitation, the latter variable being a surrogate for cloudiness which affects surface insolation. Photovoltaic electricity generation (in kWh per kilowatt of photovoltaic installed power capacity) was estimated for each month and for the entire year from the insolation models by assuming international standard values for the performance ratio of photovoltaic systems. The yearly average root mean square predictive error (RTGCV) on the mean daily global insolation ranges between 0.75 (vertical tilt) and 1.43MJ/m2 (sun-tracking orientation) (or about 4.7–9.0kWh/kW in terms of PV potential), or from 5.6% to 6.9% of the mean. Ultimately insolation and photovoltaic potential were mapped over the country at a 300 arc seconds (∼10km) resolution. The maps are available on a Natural Resources Canada Website. This is an important new tool to help Canadians gain an overall perspective of Canada’s photovoltaic potential, and allow estimation of potential photovoltaic system electricity production at any chosen location. [Copyright &y& Elsevier]

A variety of responses to climate change have been reported for northern tree populations, primarily from tree-ring and satellite-based studies. Here we employ provenance data to examine growth and survival responses of northern populations (defined here as those occurring north of 52° N) of black spruce (Picea mariana) and jack pine (Pinus banksiana) to southward seed transfers. This space for time substitution affords insights into potential climate change responses by these important northern tree species. Based on previous work, we anticipated relatively flat response curves that peak at much warmer temperatures than those found at seed source origin. These expectations were generally met for growth-related responses, with peak growth associated with seed transfers to environments with mean annual temperatures 2.2 and 3.6 °C warmer than seed source origin for black spruce and jack pine, respectively. These findings imply that northern tree populations harbor a significant amount of resilience to climate warming. However, survival responses told a different story, with both species exhibiting reduced survival rates when moved to warmer and drier environments. Together with the growth-based results, these findings suggest that the warmer and drier conditions expected across much of northern Canada under climate change may reduce survival, but surviving trees may grow at a faster rate up until a certain magnitude of climate warming has been reached. We note that all relationships had high levels of unexplained variation, underlining the many factors that may influence provenance study outcomes and the challenges in predicting tree responses to climate change. Despite certain limitations, we feel that the provenance data employed here provide valuable insights into potential climate change outcomes for northern tree populations. [ABSTRACT FROM AUTHOR]

The Emerald Ash Borer (EAB), Agrilus plaipennis (Coleoptera: Buprestidae) was introduced to North America more than two decades ago and has spread despite management efforts in both the United States and Canada. The insect kills most species of ash tree (Fraxinus sp.) and its management imposes costs to plant health protection agencies, forest industry, private landowners and municipalities. The United States Department of Agriculture – Animal and Plant Health Inspection Service (USDA-APHIS) has deemed existing regulation efforts in the United States to be ineffective and has removed federal regulations designed to limit the spread of EAB. The Canadian Food Inspection Agency (CFIA) is also trying to determine if continued regulation of EAB in Canada is worthwhile. Here we show that the benefits of slowing the spread of EAB via regulation are likely greater than the costs of implementing regulation if it is minimally effective (i.e. more than 25% effective at preventing anthropogenic spread). To evaluate the economic efficiency of existing Canadian EAB regulations, we examined trade-offs between the monetary benefits of regulation and the costs of regulation. Specifically, we simulated the spread of EAB under various levels of regulation effectiveness and estimated the timing of EAB arrival and associated ash mortality in urban and rural settings. Delaying ash mortality via regulation also delays management costs, a benefit to ash tree owners/users. Our findings suggest that an economic justification to continue regulating the insect exists based on monetary costs alone. The net present value of regulation (benefits less costs) is estimated to range between $23 million to $240 million, depending on the level of regulation effectiveness. Additional environmental and social benefits not addressed here would likely increase the value of EAB regulation but appear unneeded to justify such efforts on allocative efficiency grounds. [Display omitted] • Emerald Ash Borer causes significant tree mortality and economic costs in urban and rural settings. • Regulation delays damages and is economically efficient under a wide range of assumptions. • EAB's distribution seems likely to extend to the Pacific coast by 2035, regardless of regulation. • Cost of regulation to slow EAB spread is minimal compared to possible benefits of delaying insect. [ABSTRACT FROM AUTHOR]

Abstract: This study explores the economic feasibility of biomass for bioenergy from fast-growing hybrid poplar plantations established on agricultural lands in Canada. Using a spatial bio-economic afforestation feasibility model, we report break-even supply costs for two broad scenarios: first with only merchantable fibre having value and secondly, a “fibre-plus-carbon” scenario with carbon sequestered valued at $5t−1 CO2−e. Five levels of biomass processing capacities were examined in each scenario (90, 230, 450, 1500 and 3000ktonnes per year) using 241 settlements across Canada as potential locations for bioenergy facilities. Supply costs here include plantation establishment, maintenance, agricultural land rent, harvest and transportation to nearest community. In relative terms three geographic regions had the most promise: the northern Prairies, central Ontario and parts of the Maritime Provinces. Smaller-scale bioenergy projects were attractive for Eastern Canada (Ontario and the Maritimes). The Prairie Provinces were most attractive for larger facilities with break-even supply costs exceeding 5$GJ−1. Adding carbon incentives at 5$t−1 CO2 decreases average costs of delivered biomass by 0.57–1.38$GJ−1; however, these cost estimates are still above the current delivered costs of sub-bituminous coal. [Copyright &y& Elsevier]

Currently predicted change in climate could strongly affect plant distributions during the next century. Here we determine the present-day climatic niches for 130 North American tree species. We then locate the climatic conditions of these niches on maps of predicted future climate, indicating where each species could potentially occur by the end of the century. A major unknown in this work is the extent to which populations of trees will actually track climate shifts through migration. We therefore present two extreme scenarios in which species either move entirely into future climatic niches or do not move out of their current niches. In the full-dispersal scenario, future potential ranges show decreases and increases in size, with an average decrease of 12% and a northward shift of 700 kilometers (km). In the no-dispersal scenario, potential ranges decrease in size by 58% and shift northward by 330 km. Major redistribution pressures appear to be in order under both dispersal scenarios. [ABSTRACT FROM AUTHOR]

Traditional plant hardiness zone maps identify areas that are relatively homogeneous with respect to climatic conditions that affect plant survival. Plants are typically categorized according to the most northerly, and sometimes the most southerly, zone in which they can successfully grow. This approach suffers from a number of limitations, including the coarse spatial nature of the zones and the relatively unsystematic assignment of plants to zones. Here we propose using climate envelopes to map the potential ranges of plant species in North America in wild and cultivated settings. We have initiated a major data-gathering effort that currently includes over 1.8 million georeferenced observations for more than 4100 plant species. We demonstrate the approach using sugar maple (Acer saccharum) and show the ease with which predicted climate-change impacts can be incorporated into the models. [ABSTRACT FROM AUTHOR]

Abstract: Here we present the results of an intensive modelling effort that generated 100 years (1901–2000) of monthly precipitation, and minimum and maximum temperature grids for Canada and the United States—a total of 3600 grids. From these primary climate variables, a further 2900 grids were generated for 29 annual bioclimatic indices. Models were generated using the ANUSPLIN software package, which employs thin plate smoothing splines to develop elevation dependent spatially continuous climate surfaces from noisy weather station data. As a rigorous test of the predictive accuracy of the historical surfaces, we carried out validation runs in which climate station data were withheld from the model building process. The magnitude of the withheld errors appear reasonable, ranging from about 1 to 1.5°C for temperature and 20–40% for precipitation on average. Predictive accuracy of the surfaces varied over time, with a modest improvement as the century progressed and the climate station network expanded. There was also considerable spatial variation in predictive accuracy across the continent. Not surprisingly, mountainous and coastal regions exhibited the highest errors for all climate variables, and error magnitude was closely related to the mean of the underlying climate variable. Though not developed specifically for climate change analysis, continental-scale trends calculated from our grids were comparable to those reported in the literature for several climate variables. The grids have already been used in a variety of applications and are available by contacting the senior author. [Copyright &y& Elsevier]

We have developed a spatial cost–benefit afforestation model that includes the tracking of five carbon pools. In this application we represent three possible afforestation strategies that could be implemented in Canada using plantations of hybrid poplar, hardwoods, and softwoods with average expected growth rates of 12–14, 5–7, and 5–7 m3· ha–1·year–1 respectively. The model provides spatially explicit insights into the cost effectiveness of afforestation as a carbon sequestration tool. Here we develop an elasticity metric and experiment to assess model sensitivity and use the results to make recommendations about research priorities. The most important biological variables across all scenarios include site suitability, which is related to refining the spatial estimates of potential yields, biomass to carbon ratios, and wood density. The most important economic variables include refinement and lowering of establishment costs and agricultural opportunity costs. Parameters that have a low impact on the break-even carbon price, suggesting refinements in knowledge in these areas would be relatively less beneficial, include decay rates for forest products, stand senescence age (the age when stand mortality reaches its maximum), bioenergy and pulpwood prices, and mean residual time for leaf litter. Less importance was also placed on the proportions of forest products in the total harvest and refining a fossil fuel substitution coefficient. [ABSTRACT FROM AUTHOR]

We established 480 remeasurement plots in plantations originally laid out by F.W. von Althen in the 1970s and 1980s for his pioneering work on hardwood planting in southern Ontario. We used 110 of these plots to summarize the growth and yield of black walnut (Juglans nigra L.) plantations in southern Ontario. Overall, walnut growth averaged only 2.3 m3·ha–1·year–1, reflecting the less than optimal soil conditions at the majority of sites. However, good growth rates (i.e., >5 m3·ha–1·year–1) were recorded at sites with well-drained loamy soils, particularly when walnut was interplanted with other tree species. We also carried out a detailed analysis of four of the original experiments of F.W. von Althen to examine the long-term impacts of silvicultural treatments applied at an early stage in plantation development. Briefly, these analyses found (i) a significant long-term effect of controlling herbaceous competition at an early point in plantation development, although there is a suggestion that lower herbicide concentrations may be adequate in the long run, (ii) that fertilization effects, which were marginal at the time of application, were not apparent at age 32, (iii) generally better walnut growth when interplanted with other woody species, but autumn olive (Elaeagnus umbellata Thunb.), the species that stimulated the best walnut growth, grew invasively throughout the study area, thus ruling it out as a nurse species, and (iv) weak evidence that an initial spacing of 3 m × 3 m is optimal for walnut development in the absence of thinning up to age 30. This study provides rare insight into black walnut growth rates and best management practices in southern Ontario, although we recognize that the scope of these findings is limited by less than optimal soil conditions at many of the study sites. [ABSTRACT FROM AUTHOR]

Afforestation is one of several possible mechanisms available to sequester carbon and help reduce greenhouse gas concentrations. We have developed a spatial Monte Carlo-based simulation model, Canadian Forest Service—Afforestation Feasibility Model (CFS-AFM) to help assess the financial attractiveness of afforestation as a means of carbon storage in Canada. The model tracks five carbon pools and simulates costs and benefits of plantation investments. In this paper we simulate three afforestation scenarios that could be used in Canada; plantations using hybrid poplar, hardwoods, and softwoods with average growth rates of 14 and 6–7 m3/ha/year, respectively. The attractiveness of afforestation is driven by regional cost and plantation productivity variation and carbon price expectations. The results indicate that afforestation would be an attractive investment in many areas of the country at carbon prices of $10 per metric ton of CO2 or higher. However, with a zero carbon price, very little afforestation would be financially viable. Thus, with low carbon price expectations, other co-benefits may be required to make afforestation more attractive to Canadian investors. [ABSTRACT FROM AUTHOR]

Rapid changes in serum sodium concentration can result in adverse neurological outcome. The gradual correction of hypernatremia in the setting of acute renal failure can be difficult to achieve. We describe an obese female teenager who presented with severe hypernatremia, hyperosmolar hyperglycemic nonketotic coma, acute renal failure, and rhabdomyolysis. Her hypernatremia and other serum chemistries were gradually corrected by repeatedly adjusting the dialysate electrolyte composition used during continuous venovenous hemodiafiltration. She had a full recovery of her renal function. She does not have clinical neurological sequelae from hypernatremia during a 1-year follow-up period. [ABSTRACT FROM AUTHOR]

We assess risks posed by oak wilt—a disease caused by the fungal pathogen Bretziella fagacearum. Though not currently found in Canada, our distribution models indicate that suitable climate conditions currently occur in southern Ontario for B. fagacearum and two of its main insect dispersal vectors, Colopterus truncatus and Carpophilus sayi. Climate habitat for these species is projected to expand northward under climate change, with much of the oak range in eastern Canada becoming climatically suitable within the next two decades. Potential costs for the removal and replacement of oak street trees ranged from CDN$266 to $420 million, with variation related to uncertainty in costs, rate of tree replacement, and city-level estimates of oak street tree density. The value of standing oak timber in eastern Canada was estimated at CDN$126 million using provincial stumpage fees and as a CDN$24 million annual contribution to national Gross Domestic Product (GDP) when calculated using a combination of economic and forestry product statistics. These values can help inform the scale of eradication and/or management efforts in the event of future oak wilt introductions. [ABSTRACT FROM AUTHOR]

Forestry projects participate in carbon markets by sequestering carbon dioxide equivalent (CO2e) and producing carbon offsets. The creation of forest-based offsets is guided by protocols that dictate how sequestered CO2e is converted into marketable offsets. Existing protocol designs aim to produce offsets that meet sustainability requirements, while providing financial incentives for landowner participation. However, limited Canadian uptake implies that current financial incentives are insufficient to encourage the production of carbon offsets via private landowners. Here we consider various design features of four protocols and their financial implications for an illustrative afforestation project in southern Ontario, Canada. We explore the protocols (two tonne–tonne protocols and two tonne–year protocols) under two afforestation project management systems ("no-harvest" and "harvest" management scenarios). Results indicate that a project that terminates in a harvest is not economically attractive at current CO2e prices under any protocol design at a scale likely to be undertaken in southern Ontario, Canada. Projects that do not conclude in harvest are generally more attractive. Tonne–tonne protocols that pay upfront for sequestered CO2e improve the economic attractiveness of afforestation projects, but the delayed realization of the value of offset credits under tonne–year protocols reduces the economic attractiveness of these projects. We discuss these results in light of the choices facing afforestation project proponents and offset protocol designers (including governments) in general, and provide detailed insights into the financial dynamics of the Canadian case. [ABSTRACT FROM AUTHOR]

This paper presents estimates of the effects of changing climate on crop yields for grain corn and soybeans in Ontario, Canada, for 1959–2013. We were able to use a database that is more comprehensive with respect to explanatory variables than some previous efforts had available. Our model includes climate variables, prices, land quality, groundwater level, CO2 concentration, and a time trend. Our results indicate that trends in temperature and precipitation during our study period have not yet resulted in appreciable threats to crop yields in the region. [ABSTRACT FROM AUTHOR]

The growth response of trees to ongoing climate change has important implications for future forest dynamics, accurate carbon accounting, and sustainable forest management. We used data from black spruce (Picea mariana) and jack pine (Pinus banksiana) provenance trials, along with published data for three other northern conifers, to identify a consistent growth response to climate warming in which cold-origin populations are expected to benefit and warm-origin populations are expected to decline. Specifically, populations from across the geographic range of a species appear to grow well at temperatures characteristic of the southern portion of the range, indicating significant potential for a positive growth response to climate warming in cold-origin populations. Few studies have quantified and compared this pattern across multiple species using provenance data. We present a forest regeneration strategy that incorporates these anticipated growth responses to promote populations that are both local to the planting site and expected to grow well under climate change. [ABSTRACT FROM AUTHOR]

A response from the authors of an article on the role of extreme climatic change in assisted migration in forestry (forestry AM), that was published in a previous issue, is presented.

The importance of human behavior in biodiversity conservation is widely recognized, but there is little published evidence about how conservation professionals make decisions when conservation values are at stake. We take a behavioral economics approach, administering simplified decision problems ("choice experiments"), questions about choice‐relevant preferences and views ("elicitation questions"), and a psychometric scale (the New Ecological Paradigm scale) to a difficult‐to‐recruit sample (n = 100) of Canadian professionals involved in managing Rangifer tarandus caribou (Woodland Caribou). Our choice experiments reveal the importance of several decision biases (risk aversion, commission bias, and a bias towards fairness) in this influential group of conservation stakeholders. We then examine in‐sample differences between categories of professional affiliation (e.g., resource industry, environmental nongovernmental organization, or federal/provincial government), finding significant variation in responses to one elicitation question (reference points) and in psychometric scores. We discuss the implications of our findings for choice in conservation practice and for multistakeholder conservation policy. Comparing our findings to prior work on choice under uncertainty in nonconservation contexts suggests a possible replication problem in applying behavioral science insights to conservation problems, pointing to the need for a systematic research program. Results from development testing with a convenience sample of university students are presented for comparison throughout the study. This is an experimental behavioral economics study of decision making among conservation professionals. It finds evidence of several important decision biases, as well as between‐group differences in worldview and environmental attitudes. [ABSTRACT FROM AUTHOR]

This study assesses the supply of switchgrass and miscanthus, in Ontario, Canada, under different biomass prices and supply chain structures, using an integrated economic, biophysical and GIS model, to assess bioenergy policy. In a local, domestic supply chain, 4 million tonnes of baled biomass production per year becomes attractive for transport to the Nanticoke Generation Station at $69/t. For a larger scale export supply chain to Rotterdam in the form of biomass pellets aggregated on the farm, 20 million tonnes of production becomes attractive at approximately $198/t. For an export supply chain with aggregation at the major ports of Ontario, 20 million tonnes of baled biomass product is attractive for shipping to ports, with pellets subsequently transported to Rotterdam, at around $137/t. Higher bale transportation costs mean that agricultural lands closer to ports, but with lower yields, are preferred compared to the on-farm aggregation scenario. Given government incentives to ease the transition between annual and perennial crops and an actual realized demand from the Nanticoke Generation Station for biomass, this supply chain scenario is plausible. However, export scenarios are not attractive due to infrastructure constraints from current pellet processing capacity, and volatile international energy and commodity markets. [ABSTRACT FROM AUTHOR]

Aim: Species distribution models typically project climatically suitable habitat for trees in eastern North America to shift hundreds of kilometres this century. We simulated potential migration, accounting for various traits that affect species' ability to track climatically suitable habitat. Location: Eastern Canada, covering ~3.7 million km2. Methods: We simulated migration‐constrained range shifts through 2100 using a hybrid approach combining projections of climatically suitable habitat based on two Representative Concentration Pathways (RCP4.5, RCP8.5) for three time periods and two species distribution modelling approaches with process‐based models parameterized using data related to dispersal ability and generation time. We developed a unique "migration kernel" that uses seed dispersal traits and observed migration velocities to obtain kernel shape and dispersal probabilities for each tree species. We then calculated lags between the migration‐constrained range limits obtained through simulations and limits of climatically suitable habitat. Results: All species demonstrated northward range shifts at the leading edge of their simulated distribution through 2100, but the magnitude and rate of that shift varied by species and time period. Climatically suitable habitat limits were found to be north of simulated distribution limits across both RCPs, with lags increasing through time. On average, simulated distribution that remained within climatically suitable habitat declined more under RCP8.5 than RCP4.5, with large areas of the rear edge of the simulated distribution becoming partially or completely climatically unsuitable for many species. Main conclusions: Climatically suitable habitat limits projected for 2100 far exceeded migration‐constrained range limits for all 10 tree species, particularly for temperate species. This study underlines the limited extent to which tree species will track climate change via natural migration. Integrating observed migration velocities, seed dispersal and generation time with SDM outputs allows for more realistic evaluations of tree migration ability under climate change and may help orient forest conservation and restoration efforts. [ABSTRACT FROM AUTHOR]

SRAD, a spatially-distributed solar radiation model, was applied to a Canadian boreal forest environment in north-western Ontario. SRAD is grid based, and factors in both topo- and meso-scaled processes using a digital elevation model (DEM) and local monthly atmospheric parameters as inputs. SRAD generates estimates of incident, outgoing, and net irradiance, as well as surface and air temperatures for each point in the DEM, over any time period ranging from one day to one year. Cloudiness and other atmospheric conditions are factored into the shortwave irradiance estimates. From the DEM, the terrain effects of slope angle, aspect, and topographic shading are calculated and used to modify the estimates of shortwave irradiance. The SRAD-generated irradiance estimates for the study region were found to be consistent with irradiance data from other sources. Estimates of irradiance were most sensitive to the parameters of sunshine fraction and cloudiness. Radiation estimates were generated and compared using both a 20 m and a 100 m resolution DEM. Extremely low irradiance estimates generated at the fine scale were absent at the coarser scale. However the mean value of irradiance at both scales was estimated to be the same at 12.4 MJm-2 day-1 annually. Radiation estimates were also determined at the two scales for a series of forest research plots. For 91% of the plots, the irradiance estimates during the growing season differed by less than 0.5 MJm-2 day-1 between the two scales. Results presented here suggest that SRAD can provide useful input for predictive spatial models in boreal forest ecosystems. [ABSTRACT FROM AUTHOR]

The ongoing COVID-19 pandemic has disrupted global economic activity in all sectors, including forest industries. Changes in demand for forest products in North America over the course of the pandemic have affected both primary processors and downstream industries reliant on residues, including wood pellet producers. Wood pellets have become an internationally traded good, mostly as a substitute for coal in electricity generation, with a significant proportion of the global supply coming from Canadian producers. To determine the effect of the COVID-19 pandemic on the Canadian wood pellet industry, economic and market data were evaluated, in parallel with a survey of Canadian manufacturers on their experiences during the first three waves of the pandemic (March 2020 to September 2021). Overall, the impact of the pandemic on the Canadian wood pellet industry was relatively small, as prices, exports, and production remained stable. Survey respondents noted some negative impacts, mostly in the first months of the pandemic, but the quick recovery of lumber production helped to reduce the impact on wood pellet producers and ensured a stable feedstock supply. The pandemic did exacerbate certain pre-existing issues, such as access to transportation services and labour availability, which were still a concern for the industry at the end of the third wave in Canada. These results suggest that the Canadian wood pellet industry was resilient to disruptions caused by the pandemic and was able to manage the negative effects it faced. This is likely because of the integrated nature of the forest sector, the industry's reliance on long-term supply contracts, and feedstock flexibility, in addition to producers and end-users both being providers of essential services. [ABSTRACT FROM AUTHOR]

Concerns over global climate change have led many jurisdictions to implement strategies aimed at reducing greenhouse gas levels. One example is the replacement of coal with dedicated energy crops, such as switchgrass and miscanthus. The yields and costs of these potentially valuable bio-energy crops have been evaluated in only a few cases, and previous studies have not focused on climate change effects. This article assesses the potential yields and costs of growing switchgrass and miscanthus on the agricultural land base in Ontario, Canada, under different climate assumptions, using a GIS-based integrated biophysical and economic simulation model. The model shows that miscanthus has a mean peak yield that is 88.5% (29.6 t ha−1 compared with 15.7 t ha−1) higher and a mean farm gate break-even price that is 25.9% ($58.20 per tonne compared with $73.29 per tonne) lower than switchgrass. The impact of climate change on the yield and break-even price of switchgrass and miscanthus is dependent upon the climate model. CGCM3.1 predicts that mean peak yields of switchgrass and miscanthus could drop by 17.8% and 14.9%, whereas CCSM3.0 predicts that mean yields could increase to 41.4% and 44.9%, from 2071 to 2100, in the A2 climate scenario respectively. Both crops show promise as biomass sources for bio-energy production, but a changing global climate, along with cultivar and planting technology developments, could affect crop choices. [ABSTRACT FROM AUTHOR]

Spatial models of 1971-2000 monthly climate normals for daily maximum and minimum temperature and total precipitation are required for many applications. The World Meteorological Organization's recommended standard for the calculation of a normal value is a complete 30-yr record with a minimal amount of missing data. Only 650 stations (~16%) in Canada meet this criterion for the period 1971-2000. Thin-plate smoothing-spline analyses, as implemented by the Australian National University Splines (ANUSPLIN) package, are used to assess the utility of differing amounts of station data in estimating nationwide monthly climate normals. The data include 1) only those stations (1169) with 20 or more years of data, 2) all stations (3835) with 5 or more years of data in at least one month, and 3) as in case 2 but with data adjusted through the most statistically significant linear-regression relationship with a nearby long-term station to 20 or more years (3983 stations). Withheld-station tests indicate that the regression-adjusted normals as in dataset 3 generally yield the best results for all three climatological elements, but the unadjusted normals as in dataset 2 are competitive with the adjusted normals in spring and autumn, reflecting the known longer spatial correlation scales in these seasons. The summary mean absolute differences between the ANUSPLIN estimates and the observations at 48 spatially representative withheld stations for dataset 3 are 0.36°C, 0.66°C, and 4.7 mm, respectively, for maximum temperature, minimum temperature, and precipitation. These are respectively 18%, 7%, and 18% smaller than the summary mean absolute differences for the long-term normals in dataset 1. [ABSTRACT FROM AUTHOR]

Aim: To inform conservation planning in the face of climate change, our objectives were to map spatial patterns of tree and songbird macrorefugia; to identify climatic limiting factors by region and taxonomic group; and to quantify multi-scale topographic components of end-of-century biotic refugia. Location: United States and Canada outside the far north. Time period: End of the 21st century. Major taxa studied: Trees and songbirds. Methods: We used species distribution models for 324 trees and 268 songbirds to develop a macrorefugia index using species-specific climate velocity. Maps of multispecies refugia potential were developed for each taxonomic/functional group and quantile regression was used to identify climatic limiting factors and relationships with multi-scale topographic variables. Results: End-of-century macrorefugia for both trees and songbirds were concentrated in western mountains and, to a lesser extent, in north-eastern coastal regions. For the highest-value refugia, precipitation was generally most limiting in the north, and warm temperatures and moisture availability were limiting in the south. Tree refugia were more limited by precipitation and moisture, while songbird refugia were more limited by temperature. Upper-percentile refugia, but not median values, were well explained by topographic conditions. Songbird refugia were strongly associated with elevation, while coastal proximity and landform composition (particularly headwaters) were important for both groups. There was a general lack of concordance between patterns of current species richness and future climate refugia. Main conclusions: Macrorefugia patterns are partly explained by steep elevational or latitudinal temperature gradients and/or moderate climates, such as coastal regions. However, climatic limiting factors for these refugia suggest contrasts in the ecological processes governing warm-end range limits for different taxa in different regions. Our framework can be applied to other regions, taxa, and time periods to generate and explain biologically meaningful indices of macrorefugia for conservation planning. [ABSTRACT FROM AUTHOR]

Conserving large intact forest landscapes (IFLs) is one forest management strategy to mitigate industrial impacts on the environment. Measuring the IFL inventory at national scales has also been proposed as a means of assessing the conservation status at global scales. This paper explores the relationship between fire regimes and the size of intact forest landscapes required to meet specific conservation targets. In this paper, we demonstrate that variation in fire regimes results in changes in the minimum size of IFL required to meet habitat targets. In addition, minimum IFL size is also dependent on the nature of the habitat targets. Larger IFLs are required to improve likelihood of providing sufficient older habitat. There is significant risk of not meeting older forest age-class targets at higher annual area burned (AAB) rates, especially under climate change. In general, there is more risk of not meeting habitat targets associated with smaller IFLs, higher annual area burned (both due to spatial differences and between historical and projected burn rates under climate change), and for provision of older forests. We used habitat age-related targets as outlined in the recovery strategy for woodland caribou as an example to demonstrate the usefulness of this type of simulation experiment and risk curves to identify appropriate IFL size along a gradient of natural disturbance intensity. [ABSTRACT FROM AUTHOR]

The degree to which tree species will shift in response to climate change is uncertain yet critical to understand for assessing ecosystem vulnerability. We analyze results from recent studies that model potential tree species habitat across the eastern United States during the coming century. Our goals were to quantify and spatially analyze habitat projections and their congruence under multiple climate scenarios and to assess the implications of habitat change for forest vulnerability and adaptation to climate change in and around protected areas. We assessed habitat projections of species habitat extent and forest composition for 35 tree species under climate change from 2000 to 2100 within National Park Service management units in the Appalachian Landscape Conservation Cooperative (ALCC), spanning an approximately 1,500 km latitudinal gradient. Our results show that forest composition and species ranges could change substantially under all greenhouse gas emissions scenarios and that model correspondence was stronger for projections of habitat declines than increases. Model correspondence generally increased at finer spatial scales, but varied by tree species and focal area. In the ALCC, forest composition was projected to change the most in protected area centered ecosystems (PACEs). Northeastern PACEs were projected to be suitable for tree species currently in southeastern PACEs, suggesting that intermediate suitable habitat regions could promote tree species persistence and mitigate the impacts of climate change on eastern forests. These results suggest that climate-specific management of eastern U.S. forest ecosystems will be critical but challenging, requiring integrated assessment and management of PACEs and protected areas as well as higher-resolution monitoring and modeling to inform spatially explicit management decisions within eastern U.S. parks. [ABSTRACT FROM AUTHOR]

Highlights: [•] Patterns and uncertainties for water budget variables were examined. [•] Water imbalance was of the similar magnitude to the uncertainties in precipitation. [•] Error sources for water imbalance were found to vary with basins and seasons. [Copyright &y& Elsevier]

Seed mass is an adaptive trait affecting species distribution, population dynamics and community structure. In widely distributed species, variation in seed mass may reflect both genetic adaptation to local environments and adaptive phenotypic plasticity. Acknowledging the difficulty in separating these two aspects, we examined the causal relationships determining seed mass variation to better understand adaptability and/or plasticity of selected tree species to spatial/climatic variation. A total of 504, 481 and 454 seed collections of black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb) across the Canadian Boreal Forest, respectively, were selected. Correlation analyses were used to determine how seed mass vary with latitude, longitude, and altitude. Structural Equation Modeling was used to examine how geographic and climatic variables influence seed mass. Climatic factors explained a large portion of the variation in seed mass (34, 14 and 29%, for black spruce, white spruce and jack pine, respectively), indicating species-specific adaptation to long term climate conditions. Higher annual mean temperature and winter precipitation caused greater seed mass in black spruce, but annual precipitation was the controlling factor for white spruce. The combination of factors such as growing season temperature and evapotranspiration, temperature seasonality and annual precipitation together determined seed mass of jack pine. Overall, sites with higher winter temperatures were correlated with larger seeds. Thus, long-term climatic conditions, at least in part, determined spatial variation in seed mass. Black spruce and Jack pine, species with relatively more specific habitat requirements and less plasticity, had more variation in seed mass explained by climate than did the more plastic species white spruce. As traits such as seed mass are related to seedling growth and survival, they potentially influence forest species composition in a changing climate and should be included in future modeling of vegetation shifts. [ABSTRACT FROM AUTHOR]