Growing High Quality Trees Crop tree selection Crop tree ......•Straight, branch-free bole Ideal...
Transcript of Growing High Quality Trees Crop tree selection Crop tree ......•Straight, branch-free bole Ideal...
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Growing High Quality Trees
Crop tree selection and
treemarking
Minga O’Brien, MSc, Forest Tech
October 2, 2010
Crop tree selection
• managing individual trees to grow high quality
sawlogs
Hemlock logsWhite pine logs
What are crop trees?• Better quality trees in a stand
• To be harvested later
• Straightness, vigour, lack of limbs & defects, $value
Red oakWhite
ash
Red
spruce
More crop trees species
White pine Yellow birch Eastern hemlock
Ideal crop tree:
• Dominant or co-dominant crown position
Ideal crop tree:
• Good-sized crown
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Ideal crop tree:• Well-balanced crown
• Straight, branch-free bole
Ideal crop tree:
• Crown has lots of fine branching
• Dead branches, thinning needles not good
Low High
White ash
Red oak
Ideal crop tree:
Bark:
• Smooth
• Light-coloured
• Shallow furrows
• Tight, not flaky
Vigorous yellow birch: shiny, light-coloured
Low High
Assessing risk
• Is tree going to die
before next cutting
cycle?
• Are the risks major
or minor?
Assessing riskLow risk = Acceptable Growing Stock
High risk = Unacceptable Growing Stock
UGS trees have decay, damage or structural defects
Target canker Spiny tooth fungus
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Interior decay - major defect
Large dark face scarBlack bark
Butt flare
Moderate to major defects
Spiral seam
Black knot
Lean
Structural defects
Weevil damage
on white pine
Sweep V-shaped fork
Can the tree respond to more light?
Tree species that increase in growth with more
light:
•Sugar maple, hemlock, white ash, red oak, red
spruce, white spruce
Tree species that respond well to more light when
young:
•Yellow birch, white pine
How to manage for crop trees?
• Thinning treatment to release crowns of chosen
crop trees by removing less desirable trees
• Promote growth & quality development of your
best, highest potential trees
Select Crop Trees Identify Competing Trees Remove Competing Trees
Spacing is important!
• Ensure adequate growing space for crown & root
development of crop trees
• A healthy crown grows outward each year - up to 1
foot per year
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Be patient!• Do not remove all UGS in one entry
• Gradual release of crop tree crowns
• Important to maintain canopy cover
Shade tolerance
• Shade reduces direct sunlight, maintains
moisture, protects against weather
• Some species grow under shaded
conditions, others do not
• Smaller openings encourage hemlock,
sugar maple, red spruce
Red spruce, hemlock, white pine
& red oak regeneration under
partial tree canopy
Treemarking
• Marking of trees for harvest, or for retention
• Key step towards growing high quality logs
• Careful selection of trees based on tree size,
vigour, quality, biodiversity
and wildlife values
Why mark trees?• Small investment with good return
• Sawlogs prices of some species have steadily increased
• Well managed woodlot can increase growth of crop
trees
How can it help?
• Increases familiarity with woodlot
• Facilitates planning for access,
felling and extraction
• Cutting and harvesting
operations more efficient
• Allows woodlot owner to
visualize the harvest and
influence choices
Is treemarking different from
crop tree selection?
Treemarkers have to take
into account many
factors:
tree vigour and defects,
shade tolerance,
site conditions,
wildlife habitat,
forest biodiversity.
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Costs
• Costs vary with terrain, size of area to be
marked, boundary lines, access,
treemarking paint, and travel distance
• The cost may be covered by funds made
available through the Forest Sustainability
Regulations
Treemarking 101
#1. Cut the worst first.
Remove trees with cankers and fungi
Remove severely damaged trees
Remove poorly formed trees
Remove trees with low vigour
Pre-harvest Post-harvest
#2. Maximise future growth.
Retain healthy well-formed trees
Space AGS trees
Know what species
respond to light
Maintain basal area
Treemarking 101
#3. Retain trees of all sizes.
How many trees are 4”-10” in diameter? 10”-
14”? 14-18”?
Take 1 out of every 3 or 4 trees in every size
class
Treemarking 101
#4. Maintain diversity.
Keep a range of tree species
Do not remove uncommon tree species
Keep conifers in hardwood stands, and
hardwoods in conifer stands
Be careful near wet areas and unusual stands
Treemarking 101#5. Wildlife need a home too.
Keep cavity trees
Keep mast trees
Protect active and inactive stick nests
Treemarking 101
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Be flexible!