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)

12

(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