10/5/2010
Biol 2346 – Lecture Topic 5
Silvicultural Tree Marking I Single Tree Selection
Vigour and Stand Structure
Outline
• The importance of silvicultural tree marking
• Tree marking and emulation of natural disturbance
• Site factors: species and ecosite
• Marking for Single Tree Selection
– Tree Level
• Vigour, Risk, Quality
– Stand Level
• Species Composition, Crown Closure, Structure, Density, Stocking
S i C
iti
C
Cl
St t
D it St ki
• Example
– Tolerant hardwood marking in central Ontario.
• Biol 2346 Tree Marking Protocol
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The Importance of Tree Marking
Tree Markers Must be:
• Knowledgeable
• Decisive
• Adaptive
• Consistent
OMNR (2004)
Partial Cutting Systems in Ontario
1. Single Tree Selection
2. Group Selection
3. Uniform Shelterwood
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The Central Role of Tree Markers
FMP
Stand Analysis
Forest Operations Prescription
Silvicultural
Tree Marking
FRI
Harvest
Regeneration and Growth (Natural, Planted) (Tending)
Tree Marking and other Disturbances
Habitat Selection
Product Recovery
1. Medium Intensity Ground Fire
2. Exploitive Logging
Pw Dominated Mixedwood Forest
3. Logging after Certified Tree Marking
Assembled From OMNR (2004)
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Site Factors: Species Composition
OMNR (2004)
Site Factors: Quality and Productivity
OMNR (2004)
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Single Tree Selection
g
Tree‐level Considerations for Marking
Tree Vigour
Tree Risk
Tree Quality
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Crown Position
OMNR (2004)
LCR = (22/30)*100
= 73.3 %
30 m
Crown Attributes
Live crown ratio(LCR)
Crown Quality
8 m
0 m
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Bark Characteristics
• Bark growth accommodates expansion of the stem diameter
Indicators of high quality
OMNR (2004)
Competition and Release Response
• Trees are competing within a dominance hierarchy.
• Removal of competing trees will initiate a growth response in residuals, which varies according to individual trees (vigour) and species (physiology).
• Good Response:
• Moderate Response:
2004
• Poor Response:
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Risk Factors
Other Factors
OMNR (2004)
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Major Defects (Biotic)
OMNR (2004)
Major Defects (Biotic)
OMNR (2004)
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Major Defects (Abiotic)
OMNR (2004)
Moderate Defects OMNR (2004)
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Minor Defects
OMNR (2004)
Residual Tree Classification
OMNR (2004)
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Defect Classes
OMNR (2004)
Stand‐level Considerations for Marking
Species composition
Crown closure
Structure
Densityy
Stocking
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Stand Structure – The Reverse J Curve
Reverse J Curve
Q factor
OMNR (2004)
Stocking Levels
OMNR (2004)
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Conceptual Model of Sustained Productivity
OMNR (2004)
Stand Structure and Productivity
OMNR (2004)
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Decision Key for Tolerant Harwoods
•
Basal area, size class distribution, species composition, quality (proportion of stand in AGS trees), and regeneration influence decisions.
•
The selection system requires that a minimum BA and quality threshold be met for implementation.
•
There are many options available for the prescription, including a delay of operations in the stand.
OMNR (2004)
Improving Stand Quality
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An Example Marking Exercise
•
Sugar Maple dominated stand in central Ontario.
•
Overstocked in all size classes except poles, little recruitment of understorey trees.
•
AGS at the stand level is 13.9 m2
ha‐1; however, the large size class is mostly UGS.
•
Marking focused on removal of Marking
focused on removal of
small and large saw logs, and retention of AGS trees.
•
Trees from other size classes were removed to release high quality trees.
OMNR (2004)
Marking Conventions
OMNR (2004)
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Biol 2346 Protocol for Single Tree Selection Marking
1.
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2.
3.
4.
5
5.
6.
7.
Determine basal area, composition and structure by conducting a wedge prism stand analysis.
C id th t
Consider the target marking prescription to be the standard of 20m
t
ki
i ti t b th t d d f 20 ‐22 BA in a BA i
structure of 6:6:5:3 (poles: small saw logs: medium saw logs: large saw logs). Determine the approriate level of retention based on your stand anlaysis
(e.g. if you are in a stand at 32 m2/ha you need to remove approximately 12 m2)
Assess each tree in the 20 x 20 m plot (400 m2 or 1/25 of a Ha) and mark the trees for RETENTION with flagging tape. Consider vigour, risk and quality when making marking decisions.
Identify defects and classify trees as AGS or UGS
Identify defects and classify trees as AGS or UGS. Retain AGS trees wherever possible, and endeavor to increase the proportion of AGS trees in the stand through your marking.
Adhere to the guidelines for retention of wildlife habitat and biodiversity (Next Lecture).
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