Recent electrophysiological research has sought to elucidate the neural mechanisms necessary for the conscious awareness of action errors. Much of this work has focused on the error positivity (Pe), a neural signal that is specifically elicited by errors that have been consciously perceived. While awareness appears to be an essential prerequisite for eliciting the Pe, the precise functional role of this component has not been identified. Twenty-nine participants performed a novel variant of the Go/No-go Error Awareness Task (EAT) in which awareness of commission errors was indicated via a separate speeded manual response. Independent component analysis (ICA) was used to isolate the Pe from other stimulus- and response-evoked signals. Single-trial analysis revealed that Pe peak latency was highly correlated with the latency at which awareness was indicated. Furthermore, the Pe was more closely related to the timing of awareness than it was to the initial erroneous response. This finding was confirmed in a separate study which derived IC weights from a control condition in which no indication of awareness was required, thus ruling out motor confounds. A receiver-operating-characteristic (ROC) curve analysis showed that the Pe could reliably predict whether an error would be consciously perceived up to 400 ms before the average awareness response. Finally, Pe latency and amplitude were found to be significantly correlated with overall error awareness levels between subjects. Our data show for the first time that the temporal dynamics of the Pe trace the emergence of error awareness. These findings have important implications for interpreting the results of clinical EEG studies of error processing.

An algorithm (Weather Reader) was developed and used to analyze daily weather records from all existing Canadian and American weather stations of eastern North America (in excess of 2100 stations), from 1930 through 2000. Specifically, the Weather Reader was used to compile daily minimum, mean, and maximum air temperatures for weather stations with at least 30 years of data, and was used to calculate accumulated degree days for winter thaw–freeze events relevant to yellow birch (Betula alleghaniensis Britt.) from beginning to end. A thaw–freeze event relevant to yellow birch was considered to take place when (i) the station daily maximum temperature reached or exceeded +4°C after being below freezing for at least 2 months of the winter, (ii) sufficient growing degree days accumulated (>50 growing degree days) to cause the affected yellow birch trees to prematurely deharden, and (iii) the daily minimum temperature dropped below −4°C causing roots and/or shoots of dehardened trees to experience freeze‐induced injury and possibly dieback. The threshold temperature of +4°C represents the daily temperature above which biological activity occurs in yellow birch. The station growing degree day summaries were subsequently spatially interpolated with the Kriging function in GS+™ and mapped in ArcView™ GIS in order to display the geographic extent of the most severe thaw–freeze events. The ArcView™ maps were then compared with the extent of historically observed yellow birch decline. It was found that the years 1936, 1944, and 1945 were particularly uncharacteristic in terms of region‐wide winter thaw–freeze extremes, and also in terms of observed birch decline events during 1930–1960. An overlay of suspected accumulated birch decline based on thaw–freeze mapping and observed decline maps prepared by Braathe (1995), Auclair (1987), and Auclair et al. (1997) for 1930–1960 demonstrated similar geographic patterns. The thaw–freeze projection for 1930–1960 was shown to coincide with 83% of the birch decline map appearing in Braathe (1995) and 55% of the geographic range of yellow birch in eastern North America. Thaw–freeze mapping was also applied to two significant events in 1981. Greatest impact was recorded to occur mostly in southern Quebec and Ontario, and several American Great Lake States, specifically in northern Michigan and New York, where the greatest growing degree day accumulation prior to refreeze in late February (February 28th) was projected to have occurred; and in southern Quebec, most of Atlantic Canada, and Maine, prior to a late spring frost in mid‐April (April 17).

Harvest residues are an attractive woody biomass feedstock for bioenergy production. A portion of the total harvest residues are generally left in the cutblock due to technical and profitability constraints. A better understanding of the factors influencing the variability of residue operational recovery rate is important to inform accurately policy development on sustainable forest biomass procurement practices. We compiled the results of field trials from boreal and temperate forests to quantify the range of variation of residue recovery rates and to identify the main factors explaining this variability. The average recovery rate was 52.2%, with minimum and maximum values of 4.0 and 89.1%, and a near-normal distribution around the average. The main factor contributing to this variation was country of operations, which encompasses aspects of bioenergy policy and markets, technological learning, and forestry context. A shift in bioenergy policy, a growth in (and a change in access to) bioenergy markets, and upward movements along the technological learning curve could increase residue recovery rates approaching the highest values observed in this study, such as those in Nordic countries (72% residue recovery), or even higher if economic and technological conditions keep improving. However, local stand conditions, especially in North America where natural variability is high among forest stands, may continue to constrain operational recovery of harvest residues. Our results suggest the need for the development of policies that define practices and thresholds based on the ecological suitability of ecosystems, with clear definitions and explicit standards for harvest residue inventory, quantification, and retention.

The contribution of forest biomass to Canada’s energy production is small but growing. As the forest bioenergy industry in Canada expands, there is growing interest in more sustainably managing the wood ash that is generated as a by-product. Despite being rich in nutrients, wood ash is usually landfilled in Canada. Soil applications of ash in Canadian forests could be used to mimic some of the effects of wildfire, to replace nutrients removed during harvesting, to counteract the negative effects of acid deposition, and to improve tree growth. At present, the provincial and territorial processes for obtaining regulatory approval to use wood ash as a forest soil amendment can be challenging to navigate. Furthermore, the costs for obtaining approval and transporting and applying wood ash to the soil can render landfilling a more cost-effective method of ash management. To ensure that wood ash applications in Canadian forests are conducted safely, effectively, and efficiently, experience from European countries could provide a useful starting point for developing best practices. The results of Canadian research trials will assist policy makers and forest managers in refining management guidelines that encourage soil applications of wood ash as a forest management tool while protecting the ecology, water quality, biodiversity, and productivity of Canadian forests.

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With an apparent abundance of idled and under-utilized agricultural land in Northern Ontario, there is interest in the ability of short-rotation forests to supply bioenergy and other possible bioproducts. Once established, Short Rotation Coppice (SRC) plantations can be harvested on (roughly) three-year cutting cycles until about age 22. Purpose-grown plantations such as these could be used as stand-alone sources of fibre or used in conjunction with sources such as natural forests or woody residues. Using a recently developed land cover model we found that approximately 405 500 ha of agricultural-type land exists across Northern Ontario. Numerous scenarios were developed to calculate SRC profitability on these areas. The analyses are intended to reflect a broad range of expectations on physical yields and prices, including management costs. Although SRC involves a considerable up-front investment, our simulations suggest a significant amount of land could have a break-even biomass price of $85/oven-dried tonnes (ODT) (+/-$5/ODT) at farm gate. This farm gate biomass price represents roughly current traditional biomass prices paid. Thus SRC would need to produce biomass at a comparable cost to be a competitive option. A number of technological and price changes could increase the attractiveness of SRC systems in Northern Ontario, including decreases in establishment and management costs (while maintaining yield expectations) and improved cultivars offering increased yields.

Canada is seeking cost-effective means to mitigate anthropogenic greenhouse gas emissions, particularly CO 2 , that have been linked to global climate change. In 2003 the Government of Canada launched the Forest 2020 Plantation Development and Assessment Initiative to assess the potential for fast-growing woody crops to sequester carbon from the atmosphere. Across the country 6000 ha of plantations were established and monitored on nonforested lands (afforestation) using a variety of methods. Economic analyses assessed the investment attractiveness of this mitigation measure for a range of species and suitable lands, taking into account such factors as growth rates, agricultural opportunity costs and a range of possible carbon values. Analyses illustrated that at current trading prices for carbon and for much of the available lands and expanding markets for forest bioproducts, expected rates of return on investment for afforestation were relatively low. However, higher future carbon prices, combined with monetary values for environmental benefits, could dramatically change the economics of afforestation in the future.Key words: afforestation, carbon sequestration, forest carbon offset project, climate change mitigation, policy analysis, risk analysis, forest investment analysis, hybrids, hybrid poplar, fast-growing trees RÉSUMÉLe Canada est à la recherche de moyens pour réduire les émissions de gaz à effets de serre issues de l'activité humaine, notamment le CO 2 , qui ont été reliées aux changements climatiques de l' ensemble de la planète. En 2003, le Gouvernement du Canada a lancé le Programme d' évaluation et de démonstration de plantation de Forêt 2020 dans le but d' évaluer le potentiel d'utilisation des plantations d'arbres à croissance rapide pour piéger le carbone contenu dans l'atmosphère. Dans l' ensemble du pays, 6 000 ha de plantations sur des terrains non boisés (boisement) ont été créés et ont fait l' objet de suivis selon différentes méthodes. Des études économiques ont permis d' évaluer les incitatifs financiers rattachés à cette mesure de réduction des gaz dans le cas de différentes espèces et de divers terrains propices au boisement, en prenant en considération des facteurs comme le taux de croissance, les coûts d' opportunité agricole et un ensemble de valeurs possibles du carbone. Les études ont indiqué que selon les valeurs actuelles de transaction du carbone, de la plupart des terres disponibles et des marchés en progression des bioproduits forestiers, les taux attendus de retour sur l'investissement dans le cas de boisement étaient relativement faibles. Cependant, des valeurs plus importantes du carbone dans l'avenir associées à la valeur monétaire des bénéfices environnementaux, pourraient modifier de façon importante l'aspect écono-mique du boisement.Mots clés : boisement, piégeage du carbone, projet forestier de piégeage du carbone, mesure d'atténuation des changements climatiques, étude des politiques, analyse du risque, analyse des investissements forestiers, hybrides, peupli...