Group Selection Harvests, Patch cuts
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Group Selection Harvests, Patch cuts
description
Group Selection Harvests, Patch cuts. Objectives. To understand the concepts behind group selection To understand how to set-up group selection cuts in the field. Multi-cohort Management. Age structure Species composition Disturbance regime . Partial disturbances. dead. Tree height. - PowerPoint PPT Presentation
Transcript of Group Selection Harvests, Patch cuts
Group Selection Harvests,Patch cuts
Objectives• To understand the concepts behind group
selection
• To understand how to set-up group selection cuts in the field
Multi-cohort Management
• Age structure
• Species composition
• Disturbance regime
Partial disturbances
Tree
hei
ght
Stand AgeFull shade
Full Sun
Overs
tory
dens
ity
dead
Tree
hei
ght
Stand AgeFull shade
Full Sun
Overs
tory
dens
ity
UNCUT EDGE
GAP
OPEN
Role of impacted area
Role of impacted area
Estimate of impacted area
xx+y
y
Area lost = x2
Total area impacted = (x+y)2
Area with reduced growth (edge) = [ (x+y)2 - x2] or [2xy + y2]
xx+y
y
“Swiss cheese”
YieldY
ield
Time
Total yieldY
ield
Time
Regeneration
• Natural
• Planting
Slash disposal
• Pile and burn?–costly
Veg Management
• Difficult
• Usually manual
Precommercial thinning
• Inefficient
• Can only cover part of the area
Equipment
• Skidders
• Cable
