1. Mixedwood Management: Considerations
Coastal Silviculture Committee
Summer 2017Workshop
15th June

2. What have the Trials told us?
Alder density has an impact on conifer growth
For both Fd and Alder, pure stands develop more volume than mixed stands (at all densities)
BUT alder in Fd have larger DBH
By age Fd Ht and DBH growth is surpassing alder

4. Harvested Natural Mixedwood Stands
By age 50-60yrs volume/ha generally much higher in Mixedwood stands with more conifer
m3/ha for pure deciduous
or even 500m3/ha with a good conifer component
BUT
TASS runs for fully stocked Dr or Fd considerably higher at this age

5. Implications for TSR
Lower volumes on longer rotations will keep cut down BUT
FLNRO and not MoF………..
Visuals, Wildlife, Forest Health and Climate Change, Recreation

6. Examples of where Mixedwood Management has occurred
Haslam - elk damage to planted conifers and good alder regen
Raza - dense alder regen on perfect site
Mahood / Lake Errock - SNC impacts

7. So, Lets Assume You Want to Manage MW
You need a strategy and some standards
A clear picture of the intended outcome
What kind of mixedwood
Stocking Standard
FG criteria
Survey system / process

8. Strategy and Intended Outcome
Identify why, where and how much
Which management objectives
Which BEC areas will work
What proportion of the timber inventory and an idea of products and yields
Assuming sawlog development, what silviculture inputs required to achieve them: Stocking standard, surveys, brushing, FG criteria

9. Types of Mixedwood Conifer Leading (C) >80% basal area conifer
Conifer Leading Mixedwood (CD)
>50% but <80% basal area conifer
Deciduous leading Mixedwood (DC)
>50% but <80% basal area deciduous
Deciduous Leading (D) >80% basal area deciduous

10. Mixes Differentiated by Structural Attributes
Stratified Mixes ie Overstory / Understory which is often seen with Dr over Cw, Fd over Mb or in the ICH Ep over Cw (successional stages)
Intimate Mixtures – both share dominance with trees in the upper canopy
Ss and Act in riparian
3. Mosaic Mixtures or patches of variable size
Fd with Dr or Hw with Dr on undulating topography

11. Mosaic or Patch Mixedwood Strategies
Macro - large and discrete eg half a block
Meso – discrete patches within an SU
Micro – small patches (>1/2ha ? ) intermixed throughout a stratum.
Intimate Mixedwood – think Additive and Replacement trials OR should it be small clumps

12. Stocking Standards
Clear picture of the product objective at the stand level and at the landscape level
A definition of a FG tree in each of these structural classes is required to ensure that the desired future conditions are met
Standards can be :
Combined within the unit ie broadleaf & conifer or
Separate standard for each class within the SU.

13. Pref Species
Acc Species
Target
Minimum
Post spacing minimum
PS maximum
Bg(3.5) Fd(4) Cw(2) Dr(4)
Hw(4) Ss(3)
1200
700
1000
Unit
Pref Species
Acc Species
Target
Minimum
Post spacing minimum
PS maximum D
Dr (4)
Mb(4)
1500
1000
700 C
Fd (4) Cw (2) Bg (3.5)
Hw (4)
900
500
600
800

14. A note on Alder Stocking Standards
What is the right Standard to grow sawlogs in a reasonable time frame?
Targets……… Minimums
Dr only, probably the right one is 1500 / 1000
Dr Mb Ep, something like 1500/1000 with Dr minimum

15. Surveys and Free Grow Criteria
Develop and follow your Strategy !
Likely Mixedwood blocks can be identified during layout and SP process eg ecology and adjacent areas
Plan surveys early to avoid deleterious brushing treatments
Do your best to pre-stratify the blocks

16. For dual Standards with C/D D/C
Establish grid and plot per hectare
Determine leading designation ie C or D and then use that stocking standard
Tally plots which fall into C or D and hence overall mixedwood class eg 60%C 40%D then its CD
Determine stocking status within each timber type seperately