The potential of aspen clonal forestry in Alberta: breeding regions and estimates of genetic gain from selection

• Author(s) / Creator(s)

  • Brouard, J.S.
  • Hamann, A.
  • Gylander, T.
  • Thomas, B.R.

• Background: Aspen naturally grows in large, single-species, even-aged stands that regenerate clonally after fire disturbance. This offers an opportunity for an intensive clonal forestry system that closely emulates the natural life history of the species. In this paper, we assess the potential of genetic tree improvement and clonal deployment to enhance the productivity of aspen forests in Alberta. We further investigate geographic patterns of genetic variation in aspen and infer forest management strategies under uncertain future climates. Methodology/Principal Findings: Genetic variation among 242 clones from Alberta was evaluated in 13 common garden trials after 5-8 growing seasons in the field. Broad-sense heritabilities for height and diameter at breast height (DBH) ranged from 0.36 to 0.64, allowing 5-15% genetic gains in height and 9-34% genetic gains in DBH. Geographic partitioning of genetic variance revealed predominant latitudinal genetic differentiation. We further observed that northward movement of clones almost always resulted in increased growth relative to local planting material, while southward movement had a strong opposite effect. Conclusion/Significance: Aspen forests are an important natural resource in western Canada that is used for pulp and oriented strandboard production, accounting for similar to 40% of the total forest harvest. Moderate to high broad-sense heritabilities in growth traits suggest good potential for a genetic tree improvement program with aspen. Significant productivity gains appear possible through clonal selection from existing trials. We propose two breeding regions for Alberta, and suggest that well-tested southern clones may be used in the northern breeding region, accounting for a general warming trend observed over the last several decades in Alberta.

• Date created

  2012

• Subjects / Keywords

  • Natural-populations
  • Trembling aspen
  • Phenotypic variation
  • Seed-transfer guidelines
  • Field performance
  • Variance-components
  • Western Canada
  • Multivariate regression trees
  • Populus-tremuloides
  • Growth chamber

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3222RC1F

• License

  © 2012 Gylander et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.