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Genetics influence aspen “form,” seen here as crooked and undesirable for commercial processing purposes.
Credit: MediaMatch West Communications
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Tree breeding specialists check progress of fast-growing poplars at northern Alberta research site.
Credit: MediaMatch West Communications
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Tending the soil around trees to reduce weedy competition, combined with selected genetic traits, combine to produce fast-growing, finely-formed trees that help Alberta wood products companies develop a competitive edge.
Credit: MediaMatch West Communications
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Aspen/poplar roots produce “suckers” that become new trees very readily. Breeders take pieces of root from “superior” trees, giving them an opportunity to reproduce top-performing trees in a fast and efficient manner.
Credit: MediaMatch West Communications
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Naturally-occurring suckers can be separated and rooted in the greenhouse to give tomorrow’s high-performing trees a head start.
Credit: MediaMatch West Communications
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Naturally-occurring suckers can be separated and rooted in the greenhouse to give tomorrow’s high-performing trees a head start.
Credit: MediaMatch West Communications
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Native aspen contributes glowing fall colors to landscapes throughout Alberta.
Credit: Dr. Barb Thomas
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Selected poplar progeny given a head start in nursery conditions.
Credit: Dr. Barb Thomas
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Aspen produce catkins and seed, though most reproduction is by suckering.
Credit: Dr. Barb Thomas
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Male reproductive buds form in early fall on both aspen and poplar.
Credit: Dr. Barb Thomas
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A poplar trial plantation near Athabasca.
Credit: Dr. Barb Thomas
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A poplar trial plantation near Athabasca.
Credit: Dr. Barb Thomas
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Selecting trees for resistance to disease such as this Septoria on balsam poplar is one possible aim of tree improvement through breeding.
Credit: Dr. Barb Thomas
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Selecting trees for resistance to disease such as this Melamspora rust on poplar is one possible aim of tree improvement through breeding.
Credit: Dr. Barb Thomas
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Trees that can be relied upon to grow straight and tall – quickly – are important to the competitiveness of Alberta’s forest economy.
Credit: Dr. Barb Thomas
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Populus davidiana, an exotic poplar that can be bred with native Populus tremuloides (aspen) to produce fast-growing hybrid aspen.
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Male sex buds form near the end of shoots on Populus tremuloides (aspen). These buds are larger than the vegetative buds that produce leaves.
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This photo shows the difference in size between sex and vegetative buds. The vegetative bud is right at the tip of the shoot, and the male sex buds are clustered behind.
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A stand of native Populus tremuloides (aspen), with color starting to change as the trees prepare for dormancy.
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Populus tremuloides (aspen) leaves turn color as the tree prepares for winter dormancy.
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Populus tremuloides (aspen) shows evidence of mildew on leaves at end of growing season. Also note the rolled-leaf insect damage in centre of photo.
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Heavy crop of male catkins on Populus tremuloides (aspen) in spring. Catkins release pollen for crossing with female catkins on other trees.
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Male catkins with red pollen sacs containing the pollen grains.
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Male catkins lose red colour as the pollen is released.
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After male buds release and produce catkins, the vegetative buds at the tip of the shoot will open and produce leaves.
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Mass of Populus tremuloides (aspen) in river valley look “fuzzy” with a heavy crop of catkins. Drought often results in heavy flower crops throughout a stand.
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Pollinated female catkins developing seed in spring on Populus tremuloides (aspen).
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As the seed approaches maturity (note small white tufts that will help the seed fly), the vegetative buds produce the first set of leaves in spring.
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As the seed approaches maturity (note small white tufts that will help the seed fly), the vegetative buds produce the first set of leaves in spring.
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Tree damage can be caused by browsing animals, from squirrels to porcupines and snowshoe hares.
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Female balsam poplar releases seed in spring.
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Female balsam poplar releases seed in spring.
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Female balsam poplar releases seed in spring.
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Female balsam poplar loaded with seed in spring.
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