Jean-François Boucher

Contribution of Traditional Knowledge to Ecological Restoration: Practices and Applications

Abstract: Traditional knowledge has become a topic of considerable interest within the research and development environment. The contribution of traditional knowledge to conservation and management is increasingly recognized, and implementation endeavours are underway in several countries. The current scale of ecosystem degradation underscores the need for restoration interventions. It is increasingly recognized that successful ecological restoration depends on effective coordination of science and traditional ecological knowledge. This paper synthesizes the literature to evaluate the present and potential contribution of traditional knowledge to ecological restoration. Despite a growing number of articles published on traditional knowledge, only a few have addressed its contributions to ecological restoration per se. The main contributions of traditional knowledge to ecological restoration are in construction of reference ecosystems, particularly when historical information is not available; species selection for restoration plantations; site selection for restoration; knowledge about historical land management practices; management of invasive species; and post-restoration monitoring. Traditional knowledge and science are complementary and should be used in conjunction in ecological restoration projects. Incorporation of traditional knowledge can contribute to build a strong partnership for the successful implementation of restoration projects and increase their social acceptability, economical feasibility, and ecological viability.

Characterization of the effects and potential mechanisms leading to increased megakaryocytic differentiation under mild hyperthermia.

The physical culture parameters have important influences on the proliferation and differentiation fate of hematopoietic stem cells. Recently, we have demonstrated that CD34+ cord blood (CB) cells undergo accelerated and increased megakaryocyte (Mk) differentiation when incubated under mild hyperthermic conditions (i.e., 39 degrees C). In this study, we investigated in detail the impacts of mild hyperthermia on Mk differentiation and maturation, and explored potential mechanisms responsible for these phenomena. Our results demonstrate that the qualitative and quantitative effects on Mk differentiation at 39 degrees C appear rapidly within 7 days, and that early transient culture at 39 degrees C led to even greater Mk yields (p<0.03). Surprisingly, cell viability was only found to be significantly reduced in the early stages of culture, suggesting that CB cells are able with time to acclimatize themselves to 39 degrees C. Although mild hyperthermia accelerated differentiation and maturation of CB-derived Mks, it failed to promote their polyploidization further but rather led to a small reduction in the proportion of polyploid Mks (p=0.01). Conversely, gene arrays analysis demonstrated that Mks derived at 39 degrees C have a normal gene expression program consistent with an advanced maturation state. Finally, two independent mechanisms that could account for the accelerated Mk differentiation were investigated. Our results suggest that the accelerated and increased Mk differentiation induced by mild hyperthermia is not mediated by cell-secreted factors but could perhaps be mediated by the increased expression of Mk transcription factors.

Leaf level response of planted eastern white pine (Pinus strobus L.) seven years after intensive silvicultural treatments

The present study examines the impact of intensive silvicultural treatments on environmental conditions, leaf level morphology and physiology, and growth of planted eastern white pine (Pinus strobus L.) saplings and evaluates how silvicultural treatments and the presence of competing vegetation influence the relationships between leaf nitrogen, leaf morphology, and leaf level photosynthetic capacity of saplings. The six silvicultural treatments evaluated consisted of combinations of scarification (removal of entire humus layer), vegetation control (herbicide), and fertilization (slow release fertilizer). Competing vegetation (mainly Populus tremuloides Michx.) had negative impacts on shoot water potential (Ψx), leaf nitrogen, leaf mass per unit leaf area (LMA), height, and basal area of 7-year-old saplings. Net CO2 assimilation rate at light saturation (A; both on a mass and area basis) and stomatal conductance for water vapor (gwv) were not significantly influenced by the presence of competing vegetation. The only significant impact of competition on gas exchange variables was to decrease water-use efficiency (both instantaneous and long-term WUE as expressed by carbon isotope discrimination or Δ). Scarification significantly increased predawn Ψx, height, and basal area of suppressed saplings, and Aarea, gwv, and LMA of saplings subject to herbicide application. These positive impacts of scarification were attributed to enhanced root growth due to higher soil temperatures. No positive impact of fertilization was observed in either suppressed or open conditions. Leaf nitrogen and LMA were both driving variables for photosynthetic capacity of saplings across all conditions created by silvicultural treatments, but also within both suppressed and open conditions. This suggests that the dependency of the photosynthetic apparatus on leaf nitrogen and LMA occurs whether there is competing vegetation (and/or shade) or not. However, the gradient of light availability under suppressed conditions was accompanied by a gradient of soil temperature due to scarification. It would be pertinent to investigate more fully the interactions between light availability and soil temperature, both influencing root growth and leaf level morphology and physiology of young eastern white pine.

Radiation and soil temperature interactions on the growth and physiology of eastern white pine ( Pinus strobus L.) seedlings

A greenhouse experiment was set up during one growing season to test the hypothesis that soil temperature controls a significant part of the light response of eastern white pine (Pinus strobus L.) seedlings that is observed in the field. The experimental design was a three by three factorial split-plot design, with three levels of light availability: 10%, 40% and 80% of full light; and three levels of soil temperature: 16 °C, 21 °C, and 26 °C in the soil at midday. The results show significant interactions between light and soil temperature factors on several variables (gas exchange, root growth, leaf-mass ratio and leaf–mass per unit area), but not on shoot dry mass. These interactions indicate that, in the field, a significant proportion of the light response of young eastern white pine could result from changes in soil temperature, especially under conditions of limiting water availability. Our results suggest that soil temperature must be taken explicitly into account as a driving variable when relating the growth of young eastern white pine to photosynthetic radiation.

Carbon Footprint Assessment of a Paperback Book

This study presents the carbon footprint of a paperback book for which the cover and inside papers were produced in the United States and printed in Canada. The choice of paper mills for both cover and page papers was based on criteria such as percentage of recycled content in the pulp mix, transport distances (pulp mill to paper mill, paper mill to print), and technologies. The cradle‐to‐gate assessment of greenhouse gas (GHG) emissions follows recognized guidelines for carbon footprint assessment. The results show that the production of 400,000 books, mainly distributed in North America, would generate 1,084 tonnes carbon dioxide equivalent (CO‐eq), or 2.71 kilograms (kg) CO‐eq per book. The impact of using deinked market pulp (DMP) is shown here to be detrimental, accounting for 54% of total GHG emissions and being 32% higher than reference virgin Kraft pulp. This supports findings that DMP mill GHG emissions strongly correlate with the carbon intensity of the power grid supplying the pulp mill and that virgin Kraft mills that reuse wood residue and black liquor to produce heat and electricity can achieve lower GHG emissions per tonne of pulp produced. Although contrary to common thinking, this is consistent with the Paper Task Force 2002 conclusion for office paper (the closest paper grade to writing paper or fine paper) (EDF 2002a). To get a cradle‐to‐grave perspective, three different end‐of‐life (EOL) scenarios were analyzed, all of which included a harvested wood product (HWP) carbon storage benefit for 25 years. The GHG offset concept within the context of the book editors “carbon‐neutral” paper claims is also discussed.

Vegetation and topography interact with weather to drive the spatial distribution of wildfires in the eastern boreal forest of Canada

It is crucial to better understand and predict how burnt areas in the boreal forest will evolve under a changing climate and landscape. The objective of the present study was to predict burnt areas at several spatial and temporal scales in the Quebec continuous boreal forest and to compare the influence of weather, vegetation and topographic variables by including them and their interactions in logistic regressions. At the largest spatial scale (350 km2), the best model explained 66% of the data variability and was able to predict burnt areas with reasonable accuracy for 11 years (r = 0.48). Weather and vegetation or topographic variables had an equivalent importance, though no single vegetation or topographic variable was mandatory to the model performance. Interactions between weather and non-weather variables largely improved the model, particularly when several weather indices were used, as the sign of the interaction with a non-weather variable could differ between weather indices. Vegetation and topography are therefore important predictors of fire susceptibility, but risk factors may vary between wind- and drought-driven fire weather. Including at least some vegetation and topographic variables in statistical models linking burnt areas to weather data can greatly improve their predictive power.

Greenhouse Gas Emissions after Application of Landfilled Paper Mill Sludge for Land Reclamation of a Nonacidic Mine Tailings Site

Large areas of mine tailings are reclaimed by applying organic amendments such as paper mill sludge (PMS). Although mining industries can use PMS freshly generated by paper mills, operational constraints on paper industries make temporary landfilling of this material an unavoidable alternative for the paper industries, creating the most prominent PMS source for mining industries. This study aimed to quantify soil greenhouse gas (GHG) emissions (NO, CO, and CH) after application of landfilled PMS (LPMS; i.e., excavated from a landfill site at a paper mill) and LPMS combined with a seeding treatment of white clover ( L.) on nonacidic mine tailings site prior to reforestation. Soil NO, CO, and CH fluxes were measured after applications of 50 and 100 Mg dry LPMS ha during two consecutive snow-free seasons on two adjacent sites; LPMS was applied once in the first season. The LPMS application increased NO emissions (7.6 to 34.7 kg NO-N ha, comprising 1.04 to 2.43% of applied N) compared with the unamended control during the first season; these emissions were negligible during the second season. The LPMS application increased CO emissions (∼5800 to 11,400 kg CO-C ha, comprising 7 to 27% of applied C) compared with the unamended control on both sites and in both seasons. Fluxes of CH were negligible. White clover combined with LPMS treatments did not affect soil GHG emissions. These new GHG emission factors should be integrated into life-cycle analyses to evaluate the C footprint of potential symbioses between the mining and paper industries. Future research should focus on the effect of PMS applications on soil GHG emissions from a variety of mine tailings under various management practices and climatic conditions to plan responsible and sustainable land reclamation.

Uncovering the minor contribution of land-cover change in upland forests to the net carbon footprint of a boreal hydroelectric reservoir

Hydropower in boreal conditions is generally considered the energy source emitting the least greenhouse gas per kilowatt-hour during its life cycle. The purpose of this study was to assess the relative contribution of the land-use change on the modification of the carbon sinks and sources following the flooding of upland forested territories to create the Eastmain-1 hydroelectric reservoir in Quebecs boreal forest using Carbon Budget Model of the Canadian Forest Sector. Results suggest a carbon sink loss after 100 yr of 300,000 ± 100,000 Mg CO equivalents (COe). A wildfire sensitivity analysis revealed that the ecosystem would have acted as a carbon sink as long as <75% of the territory had burned over the 100-yr-long period. Our long-term net carbon flux estimate resulted in emissions of 4 ± 2 g COe kWh as a contribution to the carbon footprint calculation, one-eighth what was obtained in a recent study that used less precise and less sensitive estimates. Consequently, this study significantly reduces the reported net carbon footprint of this reservoir and reveals how negligible the relative contribution of the land-use change in upland forests to the total net carbon footprint of a hydroelectric reservoir in the boreal zone can be.