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Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Genomics-assisted tree breeding (GATB) is an emerging biotechnology method that has the potential to produce improved planting stock in selected traits, such as greater volume or higher wood quality, more quickly and effectively compared with traditional field-based breeding (TB) methods. In this study, we conducted an ex-ante stand-level financial benefit-cost analysis that is linked to a provincial tree growth and yield projection model to investigate the potential financial benefits of using improved white spruce (Picea glauca (Moench) Voss) and lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) planting stock identified via alternative tree improvement strategies (i.e. GATB vs. TB methods) for forest companies in the province of Alberta, Canada. With consideration of major tree breeding and establishment costs, expected sawlog price premiums at harvest, a shorter breeding cycle time, and additional genetic gain in volume achieved from using the GATB method relative to the TB method in the financial analysis; this study found that the use of GATB-selected third-generation planting stock was difficult to justify economically alone compared with TB-selected seedlings under the current sawlog market value and the current planting rate with improved stock in the province. However, results of our sensitivity analysis also revealed that the GATB method is: (1) more financially supported at lower discount rates; (2) strongly supported through decreased seedling costs with increased areas planted with improved stock; and (3) strongly supported through an increase in log price premiums at harvest resulting from potentially better wood quality and higher volume production relative to TB-selected stock. The findings of this study highlight several important market and biophysical factors that forest managers should take into account when adopting biotechnology in forestry. [ABSTRACT FROM AUTHOR]

Ecological processes driving tree success in the early stages of succession are complex and often poorly understood, involving direct and indirect relationships among multiple agents modulated by legacies. Reclamation areas of open-pit mines provide a unique opportunity to study these relationships, as these sites are often homogeneous and have few ecological legacies. Our study evaluated the early performance of three boreal tree species planted at different densities over a large reclaimed landscape (57 ha) in northern Alberta, Canada, that varied in landscape topography, surface soils, and coarse woody material. A range of soil, topographical, and seedling characteristics were measured over five growing seasons. The two surface soils had stark differences in their physical and chemical properties. Overall, seedling survival was high (> 80%) for jack pine (Pinus banksiana) and white spruce (Picea glauca) and somewhat lower (60%) for trembling aspen (Populus tremuloides). All three species grew taller in the fine-textured than in the coarse-textured soils. Linear models identified simple relationships among some of the monitored variables. To further explore more complex relationships, we built a structural equation model for jack pine growth, 2 and 5 years after planting. On coarse-textured soil, the factors controlling pine growth shifted from intrinsic factors of seedling quality in the second growing season to more complex interactions in the fifth growing season, driven by soil nutrients, water availability and colonizing vegetation. We believe these models have the potential to be useful in forest reclamation, by identifying driving factors that could be monitored to indicate reclamation success. [ABSTRACT FROM AUTHOR]

Abstract: A white spruce ring-width chronology was used to reconstruct June–July mean temperatures in the northern Canadian Rocky Mountains back to 1772 A.D. Samples were collected in an old growth subalpine forest in the remote Kwadacha Wilderness Provincial Park. Two chronologies were created, one using standard dendroclimatological methods and one through the use of principal components analysis. The ring-width chronologies both showed a strong positive relationship with minimum, maximum, and mean temperatures during the current growing season. The principal component based chronology was deemed superior for use as a proxy record due to its greater ability to explain the variance in the instrumental temperature record and stronger performance during reconstruction verification. Comparison of this reconstruction with other dendroclimatological reconstructions from western Canada revealed a coherent pattern of low-frequency variability, whereas comparisons at annual times-scales showed considerable temporal and spatial variability in the level of agreement between reconstructions. The northern Canadian Rocky Mountains reconstruction showed no evidence of the reduction in sensitivity to climatic variability that has been found in many other northern spruce chronologies during the late 20th century. [Copyright &y& Elsevier]

In mixedwood boreal forests of western Canada, stands classified as “pure deciduous” by forest inventories sometimes contain a few large white spruce (Picea glauca (Moench) Voss) trees among or emerging from the canopy. These trees are important as regeneration seed sources and for habitat structure. Neither their abundance nor the characteristics of stands in which they occur have previously been quantified. Of 275 “pure aspen” stands in northeastern Alberta, 19.6% contained at least one such spruce detectable in an aerial photograph. These trees were found in stands across the range of sampled canopy heights, densities, age classes, and stand sizes and were often present in the interior of stands, not just on the perimeter. The frequency of 3 ha cells containing at least one spruce was related to (i) stand shape and size, (ii) amount of mature white spruce in adjacent forest, (iii) canopy height, (iv) stand age, and (v) stand density. We conclude that such trees are relatively abundant and widely distributed within the boreal mixedwood forests of Alberta. There is presently no provision to maintain this landscape element within managed forests. More information is needed to determine if or how they should be considered in forest management planning. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Discusses the results of a study, which explored the influence of partial harvesting and forest floor disturbance on nutrient availability and understory vegetation in boreal mixedwoods in Alberta. Factors that influence the establishment and growth of planted white spruce; Description of the forest floor disturbance treatments used in the study; Effects of harvest type on soil temperature, magnesium availability and plant density and cover.

Fallen logs of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) at various stages of decomposition were sampled from undisturbed and 1-, 14-, and 28-year-old post-fire and post-harvest sites in northern Alberta and studied for differences in the associated microfungus communities. Wood samples were plated directly onto each of six different media and, from these, fungal species were identified and enumerated over a 24-month period. Approximately 10 000 isolates were obtained, representing 292 species of filamentous microfungi, including 41 ascomycetes, 29 zygomycetes, and 222 mitosporic fungi. The most commonly isolated species were Trichoderma viride (Gray) Pers., Rhinocladiella atrovirens Nannf., Penicillium pinophilum Hedgcock, and Mortierella ramanniana (Moller) Linnem. Cluster analysis and ordination of microfungus communities in logs showed that the tree species of the log had the greatest influence on the species composition of communities. Fungus community composition was also correlated with the stage of decomposition. Species richness was highest in logs from undisturbed sites and lowest in logs from the most recently disturbed sites. Species diversity (Shannon-Weaver) was only slightly higher at undisturbed sites than at disturbed sites. The most significant environmental factor was log moisture, which increased proportionately with stage of decomposition and was significantly correlated with climatic factors.Key words: ecology, fungi, ordination, succession, species richness, diversity.Les auteurs ont échantillonné des troncs morts et gisants de peuplier faux-tremble (Populus tremuloides Michx.) et d'épinette blanche (Picea glauca (Moench) Voss) à divers stades de décomposition, sur des sites non-perturbés, et après 1, 14 et 28 ans depuis un feu ou une récolte, dans le nord de l'Alberta, puis ils en ont étudié les différences au niveau des communautés de microfungi. Des échantillons de bois ont été directement mis en plaque sur six milieux différents et, à partir de ceux-ci les espèces fongiques ont été énumérées, sur une période de 24 mois. On a ainsi obtenu près de 10 000 isolats, représentant 292 espèces de champignons filamenteux, incluant 41 ascomycètes, 29 zygomycètes, et 222 champignons mitosporiques. Les espèces les plus communément isolées sont les Trichoderma viride (Gray) Pers., Rhinocladiella atravirens Nannf., Penicillium pinophilum Hedgcock, et le Mortierella ramanniana (Moller) Linnem. L'analyse par regroupement et ordination des communautés microfongiques dans ces troncs morts montrent que l'espèce d'arbre impliquée influence le plus fortement la composition en espèces des communautés. La composition de la communauté fongique est également corrélée avec les stades de la décomposition. La richesse en espèces est la plus élevée dans les troncs morts de sites non-perturbés, et la plus faible dans les troncs morts des sites les plus récemment perturbés. La diversité en espèces (Shannon-Weaver) n'est que légèrement supérieure sur les sites non-perturbés comparativement aux sites perturbés. Le facteur environnemental le plus significatif est l'humidité de la bille, laquelle augmente proportionnellement avec le stade de décomposition et est significativement corrélée aux facteurs climatiques.Mots clés : écologie, champignons, ordination, succession, richesse en espèces, diversité.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Reports that forest policymakers in Canada are considering the allowable cut effect (ACE) as a potential mechanism to provide tenure holders with incentives to practice enhanced forest management. To investigate the incentives created by the ACE, this paper estimates returns to ACE investments for a trembling aspen (Populus tremuloides Michx.) - white spruce (Picea glauca (Moench) Voss) mixedwood forest in Alberta. A timber supply model is used to optimize harvesting schedules to maximize net present values over a 200-year planning horizon. A number of scenarios are investigated with variations in intensity of silvicultural investments, beginning age-class distributions, levels of flexibility around the allowable annual cut (AAC), calculations of AACs based on coniferous and mixedwood volumes, and green-up constraints. In our simulations, it was difficult to find positive returns to the ACE. Positive returns only occurred when operating under harvesting constraints with a mature starting forest and AAC calculations that ignored deciduous volumes. In those limited cases where there were positive returns to the ACE, returns were higher for extensive, rather than intensive investments. Combining these results with other potential impediments to the ACE, previously identified in the literature, the probability of tenure holders having incentives to undertake ACE investments is low.

Examines height growth pattern of white spruce in natural subregions in Alberta. Use of the ratio of height at 70 and 30 years of breast height age as a quantitative measure of height growth pattern; Height growth pattern in natural subregions; Prediction of white spruce site index or height.

Ecoregion-based variable-exponent taper equations for white spruce (Picea glauca (Moench) Voss) were validated on independent tree sectioning data sets. Criteria used for model validation were briefly reviewed, along with applicable interpretations. Examination of the validation plots and statistics indicated that the mean prediction biases were small and very close to zero (-0.0058 7le; ē ≤ 0.0247; -0.03% ≤ e% ≤ 0.20%), and the mean squared error of prediction was low. The agreement between observed and predicted values from the taper equations was strong and obvious, and was consistent across the size classes of the predicted values. Approximately 99% of the total variation in both the diameter inside bark predictions and volume predictions were explained by the application of the fitted taper equations. [ABSTRACT FROM AUTHOR]

Investigates the development of an individual tree-height increment models for white spruce and aspen growing in the boreal mixed-species in Alberta. Selection of a base height-increment function; Incorporation of tree and stand level variables using the parameter prediction approach.

Examines the impacts of different methods of mechanical site preparation (MSP) on performance and foliar nutrition of planted white spruce seedlings at two mixed-wood boreal forest sites in Alberta. Three types of MSP; Relative foliar nutrient content; Foliar biomass; Ion toxicity.

Reports on the use of satellite remote sensing to uncover white spruce in Alberta's aspen-dominated forests. Benefits of the technology for forest companies; Forecasting of future timber supplies; Image classification system developed by Ron Hall, a research scientist.