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The feasibility of wood based energy plants in the off-grid Brochet community in Manitoba were analyzed by survey, interviews and document review in this research. Four areas were explored to assess the suitability of biomass energy generation, namely: the community’s perspective, resource assessment, technology availability, and cost attractiveness. Harvesting sufficient woody biomass from local wild fire burnt areas, in particular, as well as local green forests could be an appropriate and feasible option. A heat only plant is considered to be the best choice for biomass plant establishment in Brochet, followed by combined heat and power plants. A cost analysis showed that a biomass plant at Brochet is more economical than the current planned investment in the diesel power facility. The lack of resolve about who wants to run and pay for the operation and the uncertainty of the reliability of biomass technologies are two large barriers to biomass energy generation in the community. Overall, biomass energy generation options are promising to eliminate or reduce the use of fossil fuel in Brochet.

Variation in snow albedo feedback (SAF) among CMIP5 climate models has been shown to explain much of the variation in projected 21st Century warming over Northern Hemisphere land. Prior studies using observations and models have demonstrated both considerable spread in the albedo, and a weak bias in the simulated strength of SAF, over snow-covered boreal forests. Boreal evergreen needleleaf forests are capable of intercepting snowfall throughout the snow season, which has a significant impact on seasonal albedo. Two satellite data products and tower-based observations of albedo are compared with simulations from multiple configurations of the Community Climate System Model (CCSM4) to investigate the causes of weak simulated SAF over the boreal forest. The largest bias occurs in April-May when simulated SAF is one-half the strength of SAF in observations. This is traced to two canopy snow parameterizations in the land model. First, there is no mechanism for the dynamic removal of snow from the canopy when temperatures are below freezing, which results in albedo values in midwinter that are biased high. Second, when temperatures do rise above freezing, all snow on the canopy is melted instantaneously, which results in an unrealistically early transition from a snow-covered to a snow-free canopy. These processes combine to produce large differences between simulated and observed monthly albedo, and are the sources of the weak bias in SAF. This analysis highlights the importance of canopy snow parameterizations for simulating the hemispheric scale climate response to surface albedo perturbations. A number of new experiments are described as recommendations for future work.

The last century, forest fires have decreased in frequency due to efficient fire-suppression along with the growth of the industrial forestry. Since 1990, fire has been reintroduced under controlled forms to recreate burnt habitats. Many species that are dependent on, or benefits from, forest fires have increased since fire was reintroduced. The importance of connectivity is often addressed in ecological research. This is particularly important for species dependent on short-lived habitats such as burnt forests. The aim of this study was to investigate if a higher connectivity between burnt forests leads to an increased occurrence of fire-related insects. The study also attempts to determine in what way connectivity and other variables in a burnt forest, such as amount of living and dead wood, distance to the coast and altitude, affects fire-related species. To investigate this, six burnt forests in Västerbotten County were sampled for fire-related insects. The sites were chosen along a gradient from high to low connectivity and close to far from the coast. The results showed that there are too few burnt forests in Västerbotten County to conduct a study of this magnitude. Still, the results provide an insight in how different environmental variables affect the number of fire-related species. The results showed a trend that increasing amount of living and dead wood and longer distance from the coast increase the local richness of fire-related species. Concerning the main aim in the study about connectivity, the analysis gives no support to either accept or reject the hypothesis.

Although boreal forest management typically results in an increased frequency of even-aged forest stands in managed landscapes, fire history research suggests that much of the natural forest mosaic is composed of stands characterised by multiple cohorts of trees. To aid in the development of multicohort management, I investigated stand structural characteristics and small mammal communities as a function of their tree cohort structures. I also tested key alternatives: stand age, productivity, and tree species composition, as correlates of structural variation and small mammal communities. Results reveal that in mixedwood and black spruce forests, three-dimensional structure of boreal forests is strongly correlated with small mammal community structure, and indicate that tree diameter distribution is a succinct descriptor of such structural variation, performing better than alternative stand characteristics. This represents a new approach to characterising habitat supply as a function of within-stand heterogeneity, contrasting with existing approaches that focus on among-stand characteristics.

Natural fire return intervals are relatively long in eastern Canadian boreal forests and often allow for the development of stands with multiple, successive cohorts of trees. Multi-cohort forest management (MCM) provides a strategy to maintain such multi-cohort stands that focuses on three broad phases of increasingly complex, post-fire stand development, termed “cohorts”, and recommends different silvicultural approaches be applied to emulate different cohort types. Previous research on structural cohort typing has relied upon primarily subjective classification methods; in this thesis, I develop more comprehensive and objective methods for three common boreal mixedwood and black spruce forest types in northeastern Ontario. Additionally, I examine relationships between cohort types and stand age, productivity, and disturbance history and the utility of airborne LiDAR to retrieve ground based classifications and to extend structural cohort typing from plot to stand-levels. In both mixedwood and black spruce forest types, stand age and age related deadwood features varied systematically with cohort classes in support of an age-based interpretation of increasing cohort complexity. However, correlations of stand age with cohort classes were surprisingly weak. Differences in site productivity had a significant effect on the accrual of increasingly complex multi-cohort stand structure in both forest types, especially in black spruce stands. The effects of past harvesting in predictive models of class membership were only significant when considered in isolation of age. As an age emulation strategy, the three cohort model appeared to be poorly suited to black spruce forests where the accrual of structural complexity appeared to be more a function of site productivity than age. Airborne LiDAR data appear to be particularly useful in recovering plot-based cohort types and extending them to the stand-level. The main gradients of structural variability detected using LiDAR were similar between boreal mixedwood and black spruce forest types; the best LiDAR-based models of cohort type relied upon combinations of tree size, size heterogeneity, and tree density related variables. The methods described here to measure, classify, and predict cohort-related structural complexity assist in translating the conceptual three cohort model to a more precise, measurement based management system. In addition, the approaches presented here to measure and classify stand structural complexity promise to significantly enhance the detail of structural information in operational forest inventories in support of a wide array of forest management and conservation applications.

Although boreal forest management typically results in an increased frequency of even-aged forest stands in managed landscapes, fire history research suggests that much of the natural forest mosaic is composed of stands characterised by multiple cohorts of trees. To aid in the development of multicohort management, I investigated stand structural characteristics and small mammal communities as a function of their tree cohort structures. I also tested key alternatives: stand age, productivity, and tree species composition, as correlates of structural variation and small mammal communities. Results reveal that in mixedwood and black spruce forests, three-dimensional structure of boreal forests is strongly correlated with small mammal community structure, and indicate that tree diameter distribution is a succinct descriptor of such structural variation, performing better than alternative stand characteristics. This represents a new approach to characterising habitat supply as a function of within-stand heterogeneity, contrasting with existing approaches that focus on among-stand characteristics.

This research investigated the natural recovery of upland boreal forest vegetation on a peat-mineral mix substrate in the Athabasca Oil Sands Region, Alberta. Three sites, aged 26 to 34 years, were assessed to determine effects of substrate (pH, electrical conductivity, texture), topography, slope, aspect, hummock size, litter depth, tall shrub and tree stem densities, canopy cover, and tree ages on community composition and cover of upland boreal vegetation. Environmental variables that had the most influence on the plant communities were substrate texture (clay), tree canopy cover, and tall shrub stem density. The plant communities, which likely developed from early successional lowland communities, most closely approximate an upland boreal mixedwood forest in transition from an early to mid successional stage. Community development was concluded to be a product of measured environmental variables, with unmeasured factors such as propagule dispersal, germination conditions, and initial species composition also playing important roles. / Land Reclamation and Remediation

主催：JST/CREST，Vrije University, ALTERRA, IBPC