Productivity? • Ecosystem? – eg, dry biomass Mg/ha/yr • Silviculture? – ? /ha/yr • ??? 1
Productivity?• Ecosystem?
– eg, dry biomass Mg/ha/yr
• Silviculture?– ? /ha/yr
• ???
1
• Parts of a slide presentation of Bruce Larson’s
• Professor, Univ of British Columbia
• Chair, Dept of Forestry
2
The term 'non-timber forest product‘ encompasses all biological materials other than timber which are extracted from forests for human use.
3
• To foresters production mostly relates to wood products only,
However Non-timber Forest Products (NTFP) are also a component of production harvests
NTFPs include:• Edible and non-edible plants and animals and their products• Medicinal products
• Wood formation (total volume) is:
(Photosynthesis-Respiration) - Allocation
Wood Products
4
“Production” implies something is produced
Harvest Index is: (harvestable volume) / (total volume)
Management can increase ‘harvest index’
- Utilization …plywood vs 2x4 vs 4x4
- Technology...less curf when cutting, lamination
- Allocation….fertilization decreases C to roots, thinning increases merchantable wood on remaining trees
Wood Products
5
Carbohydrate allocation in an even-aged stand of European beech
6
How to Measure Allocation?• Direct
– Aboveground & Belowground• Hard to measure• Manage via nutrients?
• Indirect – Stomatal Behaviour
• Measure photosyn/CO2
• Manage via water - affects stomates and absorption of CO2?
7
How to Determine or Classify Site Productivity?
• Site Index (Continuous Variable)– Height at a given age
• PNW = 50 years• SE = 25 year
– Shape• Anamorphic – ht keeps same proportion at diff ages• Polymorphic – ht proportion diff among curves
• Understory vegetation (salal, sword fern, ?)
• Soil parameter? 8
Site Class (Categorical variable)
• Site I (best) [site 40m or 132ft]
• Site III (medium) [site 30m or 100ft]
• Site V (poor) [site 20m or 66ft]
9
10
Species Matters
Height Growth
0
10
20
30
40
50
0 10 20 30 40 50 60 70 80 90 100
Age
hei
gh
t
red cedar
Douglas-fir
11
Basal Area
• Proportional to total LA accumulation over time
• Historic artifact of:
site quality X stand structure(eg, species,
even/uneven ages, tree sizes)
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(m2/m2)tree area at DBH/ground area
or (ft2/ft2)
Basal Area
050
100150
200250
300350
400450
500
0 10 20 30 40 50 60 70 80 90 100
Age
Sq
uar
e F
eet/
Acr
e
Site 20
Site 30
Site 40
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Amelioration• One of silvicultural tools
– Fertilize– Drain– Bed
• “Pseudoamelioration”– Genetic Improvement– Vegetation Management (eg,
shrubs)14
What About NTFP’s ?
• Pine mushrooms example
– Conifer dependent
– Very low production in riparian zones• (usually considered “high”sites for trees)
15
Productivity = Product Production Rate
• Know your product (be flexible, may not be “traditional”)
• Use direct measure or highly correlated surrogate
• Need element of time
• Manage your soil as well as your trees!!16