An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd...
-
date post
22-Dec-2015 -
Category
Documents
-
view
219 -
download
0
Transcript of An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd...
![Page 1: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/1.jpg)
An Introduction to Variable Retention Harvesting
BY: Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash.For more info: [email protected] or www.symmetree.ca
![Page 2: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/2.jpg)
The following people helped make this presentation possible :
Bryce Bancroft, Symmetree Consulting Group
Bill Beese, and MacMillan Bloedel (Weyerhaeuser) Ltd.
Mike Bragg and Tolko Industries, Hefley Creek, BC
Shannon Janzen – Coast Forest Conservation Initiative Group of Companies.
Jerry Franklin - University of Washington
Fred Bunnell and Laurie Kremsater, Univ of BC.
Jason Mogilefsky and Potlatch Corporation
![Page 3: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/3.jpg)
Outline
1. What is variable retention (VR)?
2. Who is doing VR?
3. Benefits and Costs?
4. What is the ecological rationale for VR?
5. How does VR fit with traditional silvicultural systems?
6. Making VR work on the ground – planning layout etc.
7. Risks – such as windthrow.
![Page 4: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/4.jpg)
So, What is variable retention?
How is it defined?
QUESTION:
![Page 5: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/5.jpg)
Variable Retention:
• A general approach to silvicultural systems and harvesting across a landscape or management unit.
• Primary objective is ECOLOGICAL • to maintain biodiversity using retention
![Page 6: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/6.jpg)
Variable Retention
Key points:• Retention is long term (rotation)• Retention is well distributed• Variable is a key – no set
patterns or amounts
![Page 7: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/7.jpg)
Who is actually doing variable retention??
QUESTION:
![Page 8: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/8.jpg)
The Pacific Northwest…
Early 1990’s Plum Creek Timber moves to reverse it’s “Darth Vader” image from the past.
![Page 9: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/9.jpg)
The BC Interior: For a range of objectives
NW BC - 1991
Southern BC - 1991
![Page 10: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/10.jpg)
The BC Interior: Current beetle epidemic
Chief Forester setGuidelines for stand level retention (10- > 25%)
![Page 11: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/11.jpg)
Mid 1990’sAlberta Pacific – Northern Alberta• Retention in the boreal forest• For habitat and biodiversity
Northern Alberta – boreal forest
![Page 12: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/12.jpg)
1998 – MacMillan Bloedel unveils “Forest Project”
BC Coast
Objective was all blocks with at least 10% retention over 5 years
![Page 13: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/13.jpg)
1999-2005• Other Companies on the Coast
using some VR.
• Retention is now a key feature in a planning area that stretches along most of the Coast.
BC Coast
![Page 14: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/14.jpg)
Other Parts of Canada:
2003 - Quebec
2003 - Ontario
![Page 15: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/15.jpg)
OK – what’s in it for me as the landowner?
QUESTION:
![Page 16: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/16.jpg)
Benefits for a small landowner
1. Helps address Social Concerns RE:– Ecological impacts of logging– Conservation of biodiversity– Other objectives – visuals?
2. Certification Requirements?• FSC?
![Page 17: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/17.jpg)
OK, What’s the COST?
QUESTION:
![Page 18: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/18.jpg)
VR Carries a Cost!
1. Less Volume and Growth– Wood left on-site
– Impacts on growth of regen
2. Increased Logging Costs
![Page 19: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/19.jpg)
Volume production losses over a rotation:
• 20-30% less yield with 43 – 65 ft2/acre uniform dispersed (15-20 % of original volume):
Zielke et al.(2002), Acker et al. (1998) Di Lucca et al. 2004
• Clumped or grouped retention – significantly less impact with significant gaps between.
• 2-5% growth reduction in addition to the volume left behind.
Palik et al. 1997, Coates 1998, Wright et al. 1990, Drever and Lertzman 2001,
Di Lucca et al. 2004
Estimates of impact on regen growth
![Page 20: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/20.jpg)
Weyco (BC Coastal) Study on for VR Harvesting Costs
• Added costs - $4.00 Cdn/m3 (range = 0 - $6.00) over and above clearcutting…or
• About $6.55 US / MBF
For:• 62% ground based• 28% cable• 10% helicopter
![Page 21: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/21.jpg)
What exactly is the ECOLOGICAL RATIONALE for variable retention?
QUESTION:
![Page 22: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/22.jpg)
Largely influenced by two ecologists / conservation biologists:
The idea to leave long term retention in BC Forests...
Jerry Franklin (University of Washington and USFS) Fred Bunnell
(University of BC)
![Page 23: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/23.jpg)
Theme – Forest species adapted to natural patterns shaped through natural disturbances
• Even severe natural disturbances don’t remove all stand structures.
• These structures fulfill a key ecological role through time – biological legacies.
![Page 24: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/24.jpg)
In the Coastal Temperate Rainforest:
• Small gaps dominate natural disturbance.
• Old forest biological legacies are pervasive on the landscape.
![Page 25: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/25.jpg)
Amount and Distribution of Biological Legacies
• varies naturally by ecosystem and associated natural disturbance regime
![Page 26: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/26.jpg)
Biological Legacies –post-disturbance function:
“Lifeboat” Species through development of next stand by providing:
• individual habitat structures, and
• intact habitat environments aggregates or groups
![Page 27: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/27.jpg)
Biological Legacies –post-disturbance function:Enrichment of Established Stands:
• A greater diversity of retained structural elements may provide a greater diversity of habitats over time.
• So KEEP IT VARIABLE
![Page 28: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/28.jpg)
Biological Legacies –post-disturbance function:Improved connectivity
• Good distribution “softens” the harvested (managed) forest matrix.
But – Can I just put all this retention on the edge of the cutblock?
![Page 29: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/29.jpg)
Biological Legacies – Improved Connectivity
• Species that disperse widely often most at risk from large scale harvesting.
• Well-distributed retention makes the harvested matrix around protected areas less hostile – more easy to move through.
![Page 30: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/30.jpg)
Connectivity – How’s the view?
You are are species that nests in old growth stands.
You don’t like being in the open too long as your enemies will get you.
AND
Mating season is near and it sure has been a long time since you had a … date
What if:
You travel widely to find food.
![Page 31: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/31.jpg)
Connectivity – Landscape vs. Stand Level retention (in the harvested matrix).
• Well-distributed retention throughout harvested units REDUCES the need for large reserves at the landscape level.
• Because the harvested matrix has more habitat value.
![Page 32: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/32.jpg)
Here is how it works…
1. Different species – different spatial and other needs.
2. Individual species – respond to influences differently at different spatial scales.
3. Processes at different scales – can be interdependent.
SO - Planning retention at multiple scales:
• helps promote the variability needed to best address the full range of species
• Provides managers with more flexibility to address a range of goals.
![Page 33: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/33.jpg)
But I don’t see how VR fits with the traditional silvicultural systems
QUESTION:
![Page 34: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/34.jpg)
• A planned program of silvicultural treatments during the whole life of the stand designed to achieve specific stand structural objectives.
Silvicultural Systems Definition
What Does this mean?
![Page 35: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/35.jpg)
Silvicultural System Definition
An long-term approach to stand management that fits with:– Stand type– Ecological conditions
Translates into:
Expected outcomes
• Product volumes
• Product values
Designed to meet
![Page 36: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/36.jpg)
Traditional Silvicultural Systems
Defined by:
1. Regeneration Methods– Planting– Natural
2. General Stand Structure– Even-aged– Uneven-aged
3. Approach to Harvest– Pattern– Timing– # of entries
FOCUS = TIMBER PRODUCTION
![Page 37: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/37.jpg)
Traditional Silvicultural Systems
Even-aged Systems– Clearcut– Seed tree– Shelterwood
Resulting stand structure is EVEN-
AGED
Initial Harvesting in Several Entries
![Page 38: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/38.jpg)
Traditional Silvicultural Systems
Selection Systems– Single-tree Selection
– Group Selection– Strip Selection
MULTI-ENTRIES - Resulting stand
structure is UNEVEN-AGED
![Page 39: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/39.jpg)
Remember…
• A general approach to silvicultural systems and harvesting across a landscape or management unit.
Variable Retention:
• Primary objective is to maintain biodiversity.
• an umbrella term under which many silvicultural systems can be used
![Page 40: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/40.jpg)
Remember Key attributes of a VR strategy…
• Retention is long term• Retention is well distributed• Variable is a key – no set patterns or amounts
![Page 41: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/41.jpg)
Can be used with multi-entry systems?
Uniform Shelterwood with retention
After last entryAfter 1st entry
Douglas-fir
W. Larch
![Page 42: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/42.jpg)
Group Selection with retention
Can be used with multi-entry systems?
![Page 43: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/43.jpg)
On the BC Coast…
• A “new” silvicultural system• Designed to:
1. Ensure good distribution of retention
2. Credibly differentiate the approach from clearcutting
The Retention System was developed for Variable Retention
![Page 44: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/44.jpg)
What is the Retention System?
Year 0
Year 25
• Retains a target amount of structure, such as live and dead trees and woody debris, for at least one rotation
• Provides structural diversity and forest or residual tree influence over the majority of a cutblock– “Influence” generally extends at least one tree length
from an edge
2001 - Mitchell and Beese, Forestry Chronicle
![Page 45: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/45.jpg)
What is meant by forest influence?
Key Points:
• Ecological zone of influence around trees and edge
• 1 tree length
For retention systems:
• influence over the majority of the cutblock.
50%+ of harvested area
![Page 46: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/46.jpg)
Ideal Retention Quality:
Ecological Value
A significant component of:
• Larger doms or vets (> 12 inches dbh)
• “Old features” – decay, large limbs, thick bark etc.
Long-lasting
• Windfirm
• Sufficiently healthy to function beyond the short term.
Safe
• Will remain safe for harvesting and planned follow-up operations.
![Page 47: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/47.jpg)
SUMMARY: Remember…
Traditional Silvicultural Systems Defined by:1. Regeneration Methods
– Planting– Natural
2. General Stand Structure
– Even-aged– Uneven-aged
3. Approach to Harvest
– Pattern– Timing– # of entries
FOCUS = TIMBER PRODUCTION
![Page 48: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/48.jpg)
SUMMARY: the retention system…
RETENTION Silvicultural Systems Defined by:
1. Retained timber for non-timber resources values– Habitat– Visuals or…
2. Ecological Influence– Leave trees– Edges
FOCUS is NOT TIMBER PRODUCTION
![Page 49: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/49.jpg)
SUMMARY: variable retention…
Variable Retention IS AN APPROACH :• to long term retention of structural attributes across a landscape
and/or management unit
Silvi systems used include:
Mostly:– Retention systems, and– Traditional systems with reserved timber
But may also include:– A component of clearcutting
A VR approach must be tailored to fit with the local ecological conditions.
![Page 50: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/50.jpg)
QUESTION:This is great on paper But how do we make it work on the ground?
![Page 51: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/51.jpg)
Planning Retention at multiple scales
Example – Northern Alberta Boreal Forest
Large intense disturbances having relatively short return intervals
![Page 52: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/52.jpg)
Landscape Remnants• 20-30 % - larger patches missed by burn and connected to unburned matrix.
Island Remnants within the burn• 3-15 % per disturbance patch (many unmappable)
From: Dave Andison’s Northern Alberta Work (2004)
Example – Northern Alberta Boreal Forest.
Planning Retention at multiple scales
![Page 53: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/53.jpg)
The flexibility of retention at multi-scales
Actual Landscape retention - 42%
Inblock retention in adjacent blocks - 16 - 22%Landscape Remnants• 20-30 % - larger patches missed by burn and connected to unburned matrix.
Island Remnants within the burn• 3-15 % per disturbance patch (many unmappable)
From: Dave Andison’s Northern Alberta Work (2004)
Example – Western Boreal Forest.
Retention at multiple scales Example – Western Boreal Forest.
![Page 54: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/54.jpg)
So, first learn about your natural disturbance regimes in the Inland Empire.
• Fire intensity, size and return intervals were naturally highly variable
• Ecological and topographical influences
• BUT still lots of overlap in time and space
Also
• Other gap disturbances (insects, disease, wind) on top of that.
![Page 55: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/55.jpg)
Next consider the landscape level context.
Think about
• Recent disturbance
• Larger landscape level reserves
• Consider other management objectives and keep it variable
• don’t do the same thing everywhere
N. Idaho
![Page 56: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/56.jpg)
Next consider the landscape level context.
N. Idaho
![Page 57: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/57.jpg)
AT THE STAND LEVEL - Be clear on your objectives…
Special Habitat?Reduced Visual
Impact?
General Maintenance of Biodiversity?
Limited Hydrologic Impact?
Regeneration?
Other?
What you are trying to achieve?
![Page 58: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/58.jpg)
Steps in Designing Stand Level Retention:
1. Management Objectives: Why are we leaving trees?
2. Stand Structural Design: What attributes are we looking for?
3. Stand Recce: Translating the Design to the Ground
5. Implementation Strategy: What do we need to do to make it work?
4. Developing silvicultural systems and retained structural options: Putting it all together:
• Leave tree opportunities• Patterns of harvest / leave trees• Available Harvesting Systems• Risk Assessment
![Page 59: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/59.jpg)
What are your desired stand level conditions?
–Does this depend on the surrounding landscape?
–Can it be altered over time?
Based on your stand knowledge and objectives, are any of the following criteria relevant?
1. Degree to which the stand can be opened up in one entry?
2. Characteristics of potential leave trees?
3. Distribution of potential leave trees?
![Page 60: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/60.jpg)
1. Management Objectives: Why are we leaving trees?
2. Stand Structural Design: What attributes are we looking for?
3. Stand Recce: Translating the Design to the Ground
5. Implementation Strategy: What do we need to do to make it work?
4. Developing silvicultural systems and retained structural options: Putting it all together:
• Leave tree opportunities• Patterns of harvest / leave trees• Available Harvesting Systems• Risk Assessment
Steps in Designing Stand Level Retention:
![Page 61: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/61.jpg)
• CONTROL POINTS – to identify structural attributes, or areas to avoid when logging:
– Engineering– Economic– Biological
STAND RECCE: ID your Control Points
Control Points help determine the mix of leave tree options by:
• Locating opportunities for leaving structure
• Helping to integrate suitable engineering considerations.
![Page 62: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/62.jpg)
1. Rock outcrops / talus
2. Snag concentrations
3. Large old veteran trees
What are biological control points (anchors)?
![Page 63: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/63.jpg)
4. Terrestrial Riparian ecosystems
5. Identified special habitats
6. Less common trees
What are biological control points?
![Page 64: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/64.jpg)
7. Less common ecosystems
8. Areas of high diversity
What are biological control points?
![Page 65: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/65.jpg)
4. Designing the Silvicultural System and Harvest Plan
Objectives and Desired Stand Conditions
Stand Recce: •Control Points
•Existing General Stand Conditions
RISKS?
Operability and Available Harvesting Systems:
Silvicultural S
ystems??
![Page 66: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/66.jpg)
CONSIDER: Operability and Available Harvesting Systems
Operability Issues
– % Slope
– Nature of Terrain
– Soil Issues
– Roadbuilding Issues
– Other?
Available Harvesting Systems
– Ground
– Cable
– Aerial
– Combinations
Opportunities for New Systems?
Consider…
![Page 67: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/67.jpg)
VR TIP at the landscape level
• Think carefully about leaving any in blocks less than 10 acres in size.
Consider this larger block on the Coast
If possible - Avoid excessive retention in small blocks
![Page 68: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/68.jpg)
VR TIP - Focus most retention in groups and clumps
Group (0.5 acre +)
Clump (less than 0.5 acre)
• With lots of space between them
![Page 69: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/69.jpg)
• Provides more support to resist wind• Contributes value for biodiversity• Combine with smaller trees if possible
VR TIP - Use larger Douglas-fir, Larch, Pine, Aspen (or other broadleaf trees) as anchors for clumps
![Page 70: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/70.jpg)
• They developed in the stand naturally as a structural unit
VR TIP - Key on natural clumps to build retention
![Page 71: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/71.jpg)
• But want to avoid going overboard
VR TIP - Use larger groups for broadleaf trees (where it fits with objectives).
• Aspen especially is highly desirable for biodiversity.
![Page 72: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/72.jpg)
• Can become excessive where there are lots of opportunities to leave trees
VR TIP - AVOID generic approaches – “leave all trees under or over a certain size”
![Page 73: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/73.jpg)
VR TIP - Mix in occasional individual trees
• Larger trees that originated above the general stand canopy
• Remember intent
![Page 74: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/74.jpg)
VR TIP - Dispersed trees (and clumps) – should be widely spaced (unless multi-entry silvicultural system)
• Intent ?• Impact on developing regen?• Site prep?
![Page 75: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/75.jpg)
• Usually 1 - 2 tree heights• Avoid in small openings
VR TIP - Dispersed trees (and clumps) – should be widely spaced
BetterOK
![Page 76: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/76.jpg)
• Indicate on logging plan
VR TIP - Plan the distribution of groups, clumps and individual trees.
Locate 2-3 Fir clumps or vets here
![Page 77: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/77.jpg)
• Within and between blocks
VR TIP - Strive for variation in amounts and patterns
![Page 78: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/78.jpg)
2nd pass area
2nd pass area
2nd pass area
Riparian area
Riparian area
Windfirm clumps
Putting it together – A layout example
![Page 79: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/79.jpg)
Eastside BC example – Williams Lake
Diverse Broadleaf / Root Rot
Large Doug-fir vets
1st entry prep cut – remove pine
UBC Alex Fraser Research Forest
Diverse Riparian Veg
![Page 80: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/80.jpg)
Blah blah blah WhateverIt’s all just going to blow down!
QUESTION/ SKEPTICISM
![Page 81: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/81.jpg)
CONSIDERATIONS:• Risk to Achieving Objectives (Timber and Non-timber)• Financial Risk – is harvesting profitable?• Windthrow Risk?• Insect and Disease Losses – now and over time?• Fire Risks – short and long term?
When Options Fully Developed - Assess Risk
RISK ASSESSMENT
![Page 82: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/82.jpg)
VR TIP - Assess windthrow risk (likelihood) and associated consequences
Choices?:• Change layout• Plan for salvage• Leave it• Windproofing treatment
• at exposed edges, and in uniform areas with dispersed retention
![Page 83: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/83.jpg)
Windthrow Hazard and Risk Assessment - BC
Symmetree Consulting Group• With Dr. S. Mitchell, Univ of BC
Soils
Windthrow Triangle
Expo
sure
Stand
Site Hazard
Low Moderate High
Exposure
Low
Mod
erat
e H
igh
Soi
ls
Overall Hazard
Low Moderate High
Site HazardLo
w M
oder
ate
Hig
h
Sta
nd
-Low -Moderate -High
VH
Windthrow Workshop –Assessments and your plan
1 Field Recce
• ID areas of HIGH (moderate) hazard
• ID areas where impact is HIGH
2 Prelim. Paper plan
3 SP Fieldwork and Layout
• Confirm wind hazard and risk
• Edges & Dispersed retention
4 Determine Amount of Expected Windthrow
Is it acceptable? Management Risk based on Consequences?
OPTIONS:
• Salvage
• Alter Layout
• Treat
IF NOT:
Windthrow Workshop
Effects of Cutblock Design on Treatment RiskAmount of “Fetch” between edges
(Rollerson and Beese, 2002) Wind
wind
![Page 84: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/84.jpg)
1. based on estimates in a sample of 2994 plots looking at windthrow 25 m into edge• 98 harvested blocks - after 2 winters of storms
Does VR just blowdown?
Average windthrow along external blk edges1:
Average = 11%
Average windthrow in large group/patch edges1:
Average = 15% 1 ha+
Average windthrow in groups/clumps: Average = 29%
(Rollerson, Beese,Smith and Peters 2005)
Windthrow Monitoring Results Weyerhaeuser 2001- 2004
![Page 85: An Introduction to Variable Retention Harvesting BY:Ken Zielke, Symmetree Consulting Group Ltd January 20, Spokane Wash. For more info: kzielke@telus.net.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d7f5503460f94a62f49/html5/thumbnails/85.jpg)
Final WordsGo Hawks