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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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

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.)

Intensive forestry systems and breeding programs often include either native aspen or hybrid poplar clones, and performance and trait evaluations are mostly made within these two groups. Here, we assessed how traits with potential adaptive value varied within and across these two plant groups. Variation in nine hydraulic and wood anatomical traits as well as growth were measured in selected aspen and hybrid poplar genotypes grown at a boreal planting site in Alberta, Canada. Variability in these traits was statistically evaluated based on a blocked experimental design. We found that genotypes of trembling aspen were more resistant to cavitation, exhibited more negative water potentials, and were more water-use-efficient than hybrid poplars. Under the boreal field test conditions, which included major regional droughts, height growth was negatively correlated with branch vessel diameter (Dv) in both aspen and hybrid poplars and differences in Dv were highly conserved in aspen trees from different provenances. Differences between the hybrid poplars and aspen provenances suggest that these two groups employ different water-use strategies. The data also suggest that vessel diameter may be a key trait in evaluating growth performance in a boreal environment. [ABSTRACT FROM AUTHOR]

Balsam poplar (Populus balsamifera L.) can easily be grown when planted as dormant, unrooted cuttings. The first part of this research project consisted of a greenhouse study to identify the best combination of pre-planting treatments to maximize rooting of hardwood cuttings for large-scale greenhouse propagation. Eighty-four treatment combinations were tested on 10 cm-long cuttings, including seven soaking lengths of time (0, 1, 2, 3, 4, 5 and 14 days), three dips (none, powder and liquid rooting hormone), two collection dates (fall and spring), and two cutting selections (average trees and a superior clone).Secondly, we tested the performance of unrooted cuttings on typical forestry sites lacking natural regeneration, using 30 cm-long cuttings and full-length whips (>60 cm). Three pre-planting treatment combinations were used (soaking for 1 or 3 days, or 3 days with a dip in rooting hormone). Other factors tested were two collection dates (fall and spring), two cutting selections (average trees and a superior clone), two storage methods (stored as full whips or cut to size), and two cutting locations (basal or top 30 cm of stools). [Copyright &y& Elsevier]

Rooting and early growth of four hybrid poplar clones (Populus spp.) planted in a greenhouse were examined after applying 40 pre-rooting treatment combinations to dormant cuttings. Treatments included 2 cutting lengths (5 and 10 cm), 5 soaking times (0, 2, 4, 8, and 12 days), and 4 dips (chitosan, rooting hormone powder, liquid rooting hormone added to the soaking water, and none). Significant differences in both rooting percentages and growth were shown between clones after 7 weeks of growth. Ten cm cuttings had 29% greater rooting success, 28% more above-ground growth, and 12% lower root /shoot ratios than 5 cm cuttings. Cuttings planted without soaking had the lowest rooting success, at less than 45% on average. Commercial rooting hormones decreased the number of rooted cuttings but increased root / shoot ratios. For optimal rooting, we recommend using 10 cm cuttings, soaked for 2 days in water (4 days for the Jackii10 clone) without any additional dipping /hormone substance. [ABSTRACT FROM AUTHOR]

For the oil sands mine sites in northern Alberta, the presence of salty process affected water, a byproduct of the hot-water bitumen extraction process, is anticipated to pose a challenge on some reconstructed landforms. The fundamental challenge when re-vegetating these sites is to ensure not only survival, but vigorous growth where plants are subjected to conditions of high electrical conductivity owing to salts in process affected water that may be contained in the substrate. Finding plants suitable for high salt conditions has offered the opportunity for Alberta-Pacific Forest Industries Inc. (Al-Pac) to investigate the potential role of using native balsam poplar (Populus balsamifera L.) as a key reclamation species for the oil sands region. Two years of greenhouse screening (2012 and 2013) of 222 balsam poplar clones from Al-Pac's balsam poplar tree improvement program, using process affected discharge water from an oil sands processing facility in Ft. McMurray, has suggested an opportunity to select genetically suitable native clones of balsam poplar for use in reclamation of challenging sites affected by process water. In consideration of the results from both greenhouse and field testing, there is an opportunity to select genetically suitable native clones of balsam poplar that are tolerant to challenging growing conditions, making them more suitable for planting on saline sites. [ABSTRACT FROM AUTHOR]

Deployment of well-adapted, water use efficient, and productive genotypes may be essential for the sustainability of both forests and wood supply for the forest industry, as climate change is increasing water stress around the world. This study aimed to characterize key traits among new genotypes of hybrid poplars (Populus spp.) in water use efficiency (WUE) and evaluate adaptive capacity to guide the selection of appropriate clones/hybrid types for commercial deployment in habitats with an increasing water deficit in northern, continental climates. Forty-five new hybrid poplar genotypes were compared at the age of 10, including two control clones, Walker and Okanese, growing in a common garden genetics trial in northern Alberta. We studied the relationships between their productivity and WUE, photosynthetic assimilation, transpiration, stomatal conductance, stomatal density and length, and leaf size and weight. In addition, the genetic variance and heritabilities of physiological and morphological characteristics related to WUE were calculated. Results of this study revealed that most of the clones showed an adaptive capacity to acclimatize (small and dense stomata) to the region of deployment. Morphological traits were characterized by higher heritabilities than physiological traits. Hybrids between Populusbalsamifera and Populus maximowiczii species showed a slightly greater adaptive potential to the area of our study than the other tested cross types. Walker, a clone widely planted across the Canadian prairies, showed inferior WUE and productivity in comparison to the new genotypes tested. Selection and tree breeding for adaptation to climate change in the region of our investigation identified highly productive genotypes with dense, small stomata and a larger leaf area to dry mass ratio. As these traits are heritable, selection of clones with these traits will ensure a faster reaction of stomata when faced with a water deficit. The low genetic effect, heritability estimates, and high residual effect for physiological traits, impose a severe limitation on the use of gas exchange measurements under field conditions in tree improvement programs selecting for drought resistance. [ABSTRACT FROM AUTHOR]

This paper describes the differences between expert and public perceptions of plantation forestry and calls for greater public participation in the development and establishment of plantations. The debate over the social acceptability of varying land-uses is essentially a debate over how land is valued and the effects of land-use change on local peoples. This study reports the findings from 31 interviews with key informants, indicating central themes such as farming identity, trust and economic competition as important to an overall assessment of community perceptions of hybrid poplar plantations. Specifically, we suggest that all of these themes are linked to complex attachments to traditional rural land-use and fear of externally motivated change. Findings from this study contribute to a greater understanding of the public values at stake around tree plantations, where experts have emphasised ecological impacts and economic trade-offs and generally disregarded the social concerns raised above. [ABSTRACT FROM AUTHOR]