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Canadian environmental governance formally began in the 1970s with an ambitious vision critical of the status quo. Until the Justin Trudeau government from 2015, this vision had been largely eroded when compared to the transformative environmental ideas, ambition, and efforts initially put forth. Drawing on elite interviews in Canadian environmental politics and an articulation of the dominant system, we develop and demonstrate a novel explanation for Canada's systematic failure to act more ambitiously on the environment. We argue that this failure is the result of progressive selection of Canadian environmental governance in relation to the dominant system at key selection moments. It is at those moments when the environment is least prioritized and the economy most urgently needs attention that environmental governance suffers the most. The paper concludes by emphasizing how features of the dominant political-economic system not typically thought of as environmental can have systematic environmental impacts. [ABSTRACT FROM AUTHOR]

The Red-headed Woodpecker ( Melanerpes erythrocephalus) is a threatened bird species undergoing continued population declines across most of its range. Despite the conservation concern, there are few published studies on the species' fecundity. We examined the nesting phenology, clutch size, and fledging success of Red-headed Woodpecker nests in southern Ontario and northern New York, where population declines are especially pronounced. We calculated the fecundity of the Red-headed Woodpecker populations from fledgling numbers and nest survival estimates. We found that nest phenology and clutch sizes were similar to those reported in other studies for the species. Red-headed Woodpecker nests monitored using video inspection had an unusually low fledging success (39%), and an average fecundity of 0.43 female fledglings per female per year. The fledgling success and fecundity for the monitored Red-headed Woodpecker population was lower than that reported by other published studies on Melanerpes spp., as well as for other genera of woodpeckers. The fecundity was also below the minimum threshold needed to offset mortality for the species, when compared to a majority of minimum fecundity values estimated from the literature. We suggest low fecundity for Red-headed Woodpeckers at the northern edge of their range may be the chronic condition of sink populations, or a more recent phenomenon for small populations approaching local extinction. [ABSTRACT FROM AUTHOR]

Rapid anthropogenic habitat changes can lead to non-ideal habitat use by animals, often resulting in lower fitness and population declines. An extreme case of use and fitness mismatch is an ecological trap where habitat quality cues are disjointed from the true quality of the habitat. Species primarily associated with anthropogenically altered habitat, such as red-headed woodpeckers ( Melanerpes erythrocephalus), may be especially vulnerable to use and fitness mismatch as they encounter novel environmental challenges. We investigated multi-scale habitat use and nesting success of red-headed woodpeckers to assess their vulnerability to mismatches between use and fitness as a result of non-ideal habitat use across multiple scales. We found that habitat characteristics that promote feeding potential such as canopy openness and greater dead limb length appeared paramount and were consistent in use across several spatial scales although reproductive fitness suffered. This contrasts with the assumption that habitat use by nesting birds should instead favor predation avoidance at smaller scales to improve reproductive fitness and suggests that maladaptive, food-based habitat use by red-headed woodpeckers in southern Ontario may result in ecological traps for the species. Whether due to poor habitat choices or costly ones in favor of feeding potential, it is vital to consider this behavior in conservation and management plans for this and similar species. We suggest multi-scale habitat use studies that consider fitness outcomes are critical for species-at-risk in human-modified landscapes. [ABSTRACT FROM AUTHOR]

Ecosystem responses to current global climate change can be predicted through experimental climate simulations. One such simulation method is the open-top chamber (OTC). The effects of OTCs on environmental factors are potentially complex, and recognizing the numerous interactions among these factors is crucial for the proper use of chambers. We studied the effects of OTCs on microclimatic factors including ambient temperature, relative humidity, soil temperature, and soil moisture. Plant abundance responses were also assessed. Our study involved the construction of 20 OTCs (1 m in diameter and 0.75 m in height; made of clear acrylic plastic) and 20 control plots on substrates with and without Sphagnum moss, at post-fire and logging sites of the transitional mixedwood-boreal forest in the southern part of James Bay region, Quebec. Experimental trials were also conducted to test the effects of OTCs on snowmelt in the Montreal region. Our results suggest that OTC treatment is most evident in terms of increased daytime maximum temperatures (2°C to 3°C), and cooler (up to ∼2.4°C), drier (up to 10% volumetric moisture content) soils. Advanced thawing of the insulating snow cover and exposure of soil in the OTCs to low spring temperatures appeared to prolong soil freeze and result in cooler soils. Earlier snowmelt probably also led to earlier onset and overall increased evaporation of meltwater in the OTCs, leading to drier soils. Plant abundance responses to OTC treatment differed depending on plant species. Overall, open-top chambers provide an effective and simple method of climate change simulation, but it is highly advisable that the complex interactive effects, both desired and undesired, are well understood and appreciated before using OTCs for experimental climate simulation. [ABSTRACT FROM AUTHOR]

Open-top chamber (OTC) climate change simulation was used to predict the potential effects of climate change on biogeochemistry, including: 1) soil decomposition of three litter types (trembling aspen ( Populus tremuloides Michx.), black spruce ( Picea mariana (Miller) BSP), and Sphagnum); 2) soil nutrient supply rates, and; 3) soil acidity. We assessed the effects of OTCs on these biogeochemical factors in the presence or absence of Sphagnum moss substrate at post-fire and logging sites, in the transitional mixedwood-boreal zone of northwestern Quebec. Higher air temperatures and cooler, drier soils created by the OTC treatment resulted in lower decomposition rates and a higher C:N ratio of aspen litter, and lower Ca concentrations of the Sphagnum litter after 14 months of incubation, as well as lower K concentrations of spruce litter after 24 month incubation. There were no effects of the OTC treatment on decomposition rates for Sphagnum and spruce litter. The nutrient supply rates of Ca and Mg were consistently lower in the OTCs. The supply rates of N were significantly higher in the control plots at the logging site than at any other combination of the OTC treatment and disturbance site. Soil pH was lower in the OTCs by the end of the growing seasons in 2006 and 2007. The results suggest that the impact of climatic changes, as simulated by the OTC treatment, on the soil system of mixedwood-boreal post-disturbance sites is likely to affect biogeochemical processes such as nutrient supply rates and the soil pH, but the effects on decomposition may be minimal. [ABSTRACT FROM AUTHOR]

Determines the nature of the negative influence of Kalmia angustifolia L. on black spruce (Picea mariana) seedling growth and foliar nutrient concentrations, and the effect of proximity to Kalmia on spruce seedlings was studied on two Kalmia-dominated sites of contrasting soil characteristics in central Newfoundland. Results of sampling of spruce seedlings and the soil at the base of their stems; Use of path analysis; How path diagrams were generated based on current knowledge of nutrient cycling in boreal ecosystems and mechanisms previously hypothesized to account for the influence of Kalmia on black spruce; Results of analysis on the wetter and richer site suggesting nutrient competition; Results on the drier and poorer site suggesting negative effect of Kalmia on the spruce.

Mosses play a key role in the carbon (C) cycle of upland black spruce ( Picea mariana (Mill.) BSP) forests; however, national reporting models such as the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) do not include mosses. This study examined whether widely available plot-level merchantable tree volume could predict, for black spruce ecosystems in Canada's boreal forest, the relative proportions of sphagnum and feather moss ground cover and moss net primary productivity (NPP). A field study found that merchantable tree volume was significantly related to tree canopy openness ( R2 = 0.61, P < 0.001), which could then be used to model the relative ground cover of feather moss ( R2 = 0.5, P < 0.001) and sphagnum ( R2 = 0.45, P < 0.001) and NPP of feather moss ( R2 = 0.41, P < 0.001) and sphagnum ( R2 = 0.28, P < 0.001). The resulting MOSS-C submodel increased the accuracy of the CBM-CFS3's prediction of organic-horizon C five-fold and could explain large-scale variation in sites dominated by sphagnum with large organic-layer C pools but not fine-scale variation in dryer sites. To improve MOSS-C accuracy, future studies should focus on varying decomposition and fire regime parameters based on regional climate or plot-level vegetation parameters. [ABSTRACT FROM AUTHOR]

The effects of secondary succession on soil nutrient availability following fire in the 1920s was investigated in a hardwood forest of southern Quebec by correlation analyses between soil and solution chemistry, tree species composition, tree growth, litterfall nutrient fluxes and presence of charcoal monitored in six 300 m2 plots between 1994 and 1998. The results suggests that the pioneer stand of largetooth aspen, paper birch and yellow birch that followed fire enriched the forest floor and upper mineral soil with its K-rich litter, but lowered solution NH4, NO3 and Mg concentrations through its high nutrient demand. High woody biomass primarily observed in the maple-dominated stands was associated with low exchangeable base cation concentrations in the forest floor, suggesting that nutrient immobilisation in trees is also a significant process leading to spatial variation in base cation availability in the forest floor. Finally, charcoal was positively correlated with exchangeable base cations in the forest floor which leads to believe that charcoal has a high affinity for base cations and that it can increase base cation availability decades after forest fire disturbance. [ABSTRACT FROM AUTHOR]

The MAKEDEP model is used to reconstruct the time-series input files of deposition, forest growth, uptake and litterfall needed to run the dynamic biogeochemical model SAFE. The amounts and timing of N made available for tree growth is what determines most of the model output. In this paper, the sensitivity of MAKEDEP tO various amounts and timing of N availability, including increased supplies of N prior to air pollution assuming increased biological N[sub 2] fixation, was assessed in a small hardwood stand of southern Quebec. The scenarios of N cycling were validated for burned and unburned conditions based on the simulated tree growth and N leaching rates as well as the model's ability to recreate the trends in atmospheric deposition of major ions in northeastern North America. The N leaching rates were calculated as the residual component of all simulated processes acting as sources and sinks of N. The N availability scenarios that subtracted/added 5 mmol m[sup -2] yr[sup -1] of NH[sub 4] in the unburned and burned conditions, respectively, recreated N leaching rates and tree biomass with the most precision. Modifying the amounts of N made available prior to air pollution was also necessary for the trees to grow to reasonable values before 1900. Historical trends of deposition were linked to the changes in the continental emissions in northeastern North America. Observational data for 30 years at the Hubbard Brook Experimental Forest, New Hampshire, showed convergent trends for most ions with the deposition trends simulated with MAKEDEP. [ABSTRACT FROM AUTHOR]

The boreal zone, a vast region with abundant natural resources and related industries, has both provisioning and nonprovisioning ecosystem services that draw some people, while warding off others. It is an area that arguably affects many Canadians in different ways and represents a wide range of tangible and intangible values. Changes in demographic patterns over time shed light on the development of the social-ecological landscape of the boreal zone, and elucidate potential changes in the future. Using past and current demographic data, we explore population size, immigration and emigration, and birth and death rates within and outside the boreal zone. We also explore links between demographics, social values, and important factors of change in the boreal zone, and present three contrasting scenarios predicting the state of this zone in 2050. We pay particular attention to the Indigenous population, generational differences, international immigration, and the urban–rural divide. Fertility rates and immigration influence population demographics within and outside the boreal zone, respectively, alluding to potential divergences in social values and between communities located within and outside the boreal zone. The boreal zone is currently comprised of many smaller towns and communities scattered across the landscape, yet it is equally important to consider the influences of larger cities located outside the boreal zone, particularly in terms of governance, population movements, and political power. Considered together, these factors provide insight on social cohesion and connectedness, demand for goods and services, and changes in boreal-centric activities. [ABSTRACT FROM AUTHOR]

Improvement in sustainable production of switchgrass (SG,Panicum virgatumL), as a purpose-grown biomass feedstock crop, could be realized through investigation of plant–microbe interactions associated with plant growth promoting rhizobacteria (PGPR), capable of biological nitrogen fixation (BNF). The objective of this study is to increase establishment year production of SG biofuels by inoculation with a mixed PGPR inoculum. We isolated pure strains of N2-fixing, and other PGPR, from SG rhizomes. The bacteria were identified asPaenibacillus polymyxa, an N2-fixing bacterium, and other PGPR capable of solubilizing phosphate and/or producing auxins. Field trials utilizing these strains in a mixed PGPR inoculum showed that inoculated plants contained more N in tillers during anthesis but not at senescence, suggesting that more N could be cycled to belowground roots and rhizomes for winter storage. The amount of N removal in biomass and recovery of fertilizer N were also greater for inoculated than uninoculated plants. PGPR inoculation also resulted in positive N balances, suggesting improved access to N from non-fertilizer N sources, possibly through BNF and improved soil N uptake. Overall, inoculation of SG with PGPR enhanced N acquisition and could be an effective strategy to increase the establishment year production of this crop. [ABSTRACT FROM PUBLISHER]

Abstract: Nitrogen-fixing bacteria (NFB) and other plant growth promoting rhizobacteria (PGPR) have been used to increase growth and yield of corn and sugarcane, two graminaceous crops utilized as bioenergy feedstocks. Switchgrass (SG, Panicum virgatum L.), a native perennial grass of North America, is also a desirable bioenergy crop because it can be grown on marginal lands and thus does not necessarily displace food production. Yet no investigations have been conducted on the use of NFB and/or PGPR as inoculants to increase SG growth and productivity. Studies reporting high biomass yields from SG with minimal to no fertilizer nitrogen (N) input prompted us to hypothesize that SG is obtaining part of its N from an alternative source, perhaps through biological nitrogen fixation from root/rhizome associated PGPR. We isolated bacteria from SG rhizomes that had not received fertilizer N input for over ten years and which increased plant growth in the absence of the fertilizer N under growth chamber conditions. The bacteria were identified as a strain of Paenibacillus polymyxa, a N2-fixing bacterium, and several other PGPR capable of solubilizing phosphate and/or producing auxins. Our objective was to test this PGPR inoculum under field conditions with low-N inputs. Here, we present the findings regarding SG productivity in the establishment year. Switchgrass seeds inoculated with the PGPR culture had greater tiller density, and taller tillers resulting in 40% higher yield than uninoculated plants. PGPR have the potential to be effectively utilized as inoculants to enhance SG yields in a low-N input production system. [Copyright &y& Elsevier]

Abstract: Stochastic simulations are increasingly used to represent and characterize the spatial structure and uncertainty of soil properties. Due to the potential presence of scale dependencies, simulations of the total variables can represent a mixture of spatial components operating at different scales, which may be better interpreted separately. While coregionalization analysis and factorial kriging provide means to characterize and estimate scale-specific components of variation, no methods are available that allow a proper representation of their spatial structure and an assessment of their spatial uncertainty. In this paper, the formulation of cokriging of regionalized components and regionalized factors is first reviewed, after which a method for the conditional Gaussian co-simulation of regionalized components and regionalized factors is presented. We highlight the need for performing conditional simulations for all structures jointly to reduce the correlation between components for different structures and avoid any bias on the sum of simulated components. Simulations obtained with this method adequately represent both the specific features of, and the uncertainty associated with, each scale of variation, as modeled in a coregionalization analysis. The method is applied to an agronomic dataset to characterize the spatial uncertainty of regionalized components of plant available phosphorous and potassium in the soil and illustrate advantages of this new simulation approach. [Copyright &y& Elsevier]

In contrast to the well-documented seasonal variation in growth of below- and above-ground components of trees, the annual variation in below- and aboveground production is not well understood. In this study, we report on the monitoring of an unmanaged hardwood forest ecosystem in a small watershed of southern Quebec between 1993 and 1999. Below- and above-ground biomass production, leaf and soil solution chemistry, and air temperature were measured at different regular intervals and are reported on an annual basis. The objective of the study was to describe the annual dynamics of carbon partitioning between below- and above-ground tree components and to gain a better understanding of the soil and climatic factors that govern it. Fine root production peaked one year earlier than woody biomass production and years with high production of fine roots had low woody biomass production. All models that included May temperature in the calculation of the predicting/independent variables were significant predictors of total tree biomass production (r > 0.87). Fine root production was associated negatively with the previous year average growing season temperature (r < -0.84). Soil solution NO3-, NH4+ and NO3- + NH4+ concentrations were positively correlated with fine root production (r > 0.72) and negatively correlated with woody biomass production (r < -0.84). Leaf N and P concentrations were negatively correlated (r = -0.99 and r = -0.98, respectively) with fine root production for the period of 1994–1998. Our results suggest that a cool growing season, and in particular a cool month of October, is likely to result in low fine root production and nutrient uptake the following year and, therefore, to increase soil N availability and decrease leaf N. This initial response is thought to be the first step of a feedback loop involving plant N nutrition, soil N availability, fine root growth and aboveground biomass production that led to a cyclical (3–4 years) but asynchronous production of fine roots and aboveground biomass production. [ABSTRACT FROM AUTHOR]

The dynamic soil model SAFE was calibrated and validated in a small hardwood forest of southern Quebec as a function of its ability to reproduce current soil chemistry and similar pre-industrial soil conditions despite the difference in forest history. SAFE was relatively accurate for reproducing soil chemistry, but comparison of pre-industrial soil conditions between unburned and burned stands casts doubt as to its applicability at sites where specific processes may be involved in nutrient cycling, e.g. the immobilization of N by microbes. Simulated soil chemistry in the unburned zone reinforced the conclusions of a few historical studies which support the hypothesis that acid-sensitive forest sites of northeastern USA underwent significant acidification when major inputs of acidity from the atmosphere occurred, i.e. during the 1930-1980 time span. Model projections in the mineral soil suggest that a new steady-state should be reached in the 21st century assuming no harvest, but that this equilibrium is broken if timber harvesting is done. Model output also suggests that cation nutrient deficiencies could occur in the long-term, but future Al phytotoxic responses are unlikely to occur due to a relatively high projected pH. Finally, it was demonstrated that the time-series files of nutrient cycling should be prepared with care as they can be the source of some abnormalities in model calibration. [ABSTRACT FROM AUTHOR]