Download presentation
Presentation is loading. Please wait.
Published byBelen Peers Modified over 9 years ago
1
Silviculture and Its Relationship to Timber Supply TSR 101 Patrick Bryant (pbryant@forsite.ca) Coastal Silviculture Committee Nanaimo - February 27, 2014 1
2
TOPICS Assumptions Results Influencing Timber Supply Nanaimo - February 27, 2014 Coastal Silviculture Committee 2
3
ASSUMPTIONS Initial Conditions Rules of Change Objectives, Criteria and Indicators Nanaimo - February 27, 2014 Coastal Silviculture Committee 3
4
Assumptions – Initial Condition Land Base Netdown (ordered removals from THLB) Total Area Less areas that cannot produce timber Forest Management Land Base (FMLB) Less areas that meet non-timber objectives (e.g., parks) Less forested areas that not merchantable or operable Timber Harvesting Land Base (THLB) Harvest and grow timber Nanaimo - February 27, 2014 Coastal Silviculture Committee 4 Netdown table
5
Assumptions – Initial Condition Age Class Distribution (also species, volumes, products, land base type, etc.) Nanaimo - February 27, 2014 Coastal Silviculture Committee 5 Reported in other periods (e.g., 50yrs, 100yrs, 200yrs)
6
Assumptions – Rules of Change Stand development (growth and yield) Aggregate stand types with similar development patterns to reduce complexity Stands under various regimes or eras, typically: Existing natural; Existing regenerated; and Future regenerated. Link to silviculture options/investments Operational adjustment Factors (OAFs) Nanaimo - February 27, 2014 Coastal Silviculture Committee 6
7
Assumptions – Rules of Change Natural disturbance (non-harvest removals) THLB = Non-recoverable losses Simply added to Harvest Rate (‘harvested’ but not reported) NHLB = Periodic disturbance events (forest health) Several approaches (e.g., Age Reset by Natural Disturbance Type – Biodiversity Guidebook – every 200 years for CWH in NDT2) If ignored, this could significantly misrepresent desired conditions for non-timber resources Nanaimo - February 27, 2014 Coastal Silviculture Committee 7
8
Assumptions – Criteria & Indicators Management objectives and options Harvest treatments Utilization levels (net volume) Merchantable criteria (min harvest age - max too) Harvest flow pattern Silviculture treatments Basic silviculture typically “assumed” (informed by, but not actual data) Tree improvement Incremental silviculture (e.g., Type 4 strategies) Treatment Types Eligible Stands Response Windows available to optimize investments Nanaimo - February 27, 2014 Coastal Silviculture Committee 8
9
Assumptions – Criteria & Indicators Management objectives and options (continued) Forest cover requirements (non-timber) Habitat suitability; ECA recovery; VQO, Green-up Nanaimo - February 27, 2014 Coastal Silviculture Committee 9 Levels for targets & accounts / Ages for constraints & recovery
10
Assumptions – Criteria & Indicators Cont’d... Forest cover requirements (non-timber) Patch size and distribution Nanaimo - February 27, 2014 Coastal Silviculture Committee 10
11
Assumptions – Criteria & Indicators Nanaimo - February 27, 2014 Coastal Silviculture Committee 11 Product profile
12
Build and Run Model “…and then some magic happens…” REALITY CHECK Only interpreting a construct; not the real forest If an assumption was not explicit – it’s not in the model Nanaimo - February 27, 2014 Coastal Silviculture Committee 12
13
Forest Estate Models A discussion for another time… by someone more knowledgeable… Several models commonly used in BC (no single model is the “prescribed”) More important to work towards understanding the forest-level dynamics Nanaimo - February 27, 2014 Coastal Silviculture Committee 13
14
RESULTS Harvest Flows Sensitivities Metrics Nanaimo - February 27, 2014 Coastal Silviculture Committee 14
15
Harvest Flow – Elements Nanaimo - February 27, 2014 Coastal Silviculture Committee 15
16
Harvest Flow - Elements Nanaimo - February 27, 2014 Coastal Silviculture Committee 16 rise
17
Harvest Flow - Patterns Nanaimo - February 27, 2014 Coastal Silviculture Committee 17
18
Harvest Flow - Patterns Nanaimo - February 27, 2014 Coastal Silviculture Committee 18
19
Harvest Flow - Sensitivities Nanaimo - February 27, 2014 Coastal Silviculture Committee 19 Compare the impacts on harvest flow of changing one or more assumptions
20
Metrics - Indicators Nanaimo - February 27, 2014 Coastal Silviculture Committee 20 Harvest Profile by age class Harvest Profile by average age, area, & volume
21
Metrics - Indicators Nanaimo - February 27, 2014 Coastal Silviculture Committee 21 Sustainable = stable growing stock & harvest rate Pinch-point & cushion limits harvest flow Merchantable growing stock directly influences harvest rate; and vice-versa Growing stock is the PRIMARY INDICATOR
22
Metrics – Value Operability Assessments Costs for harvesting, road building and silviculture Develop and link blocks to roads Values for existing and regenerated stands (based on species/age/products/market prices) Adapt harvest flows to report NPV Nanaimo - February 27, 2014 Coastal Silviculture Committee 22 Forest-level NPV over time
23
INFLUENCING TIMBER SUPPLY Methods of Influence Examples Nanaimo - February 27, 2014 Coastal Silviculture Committee 23 Growing stock Harvest rate Stand Yields
24
Methods of Influence Fit the solution to the problem – consider growing stock Aim to treat stands eligible for harvest in the right period by: ∆ development pattern of individual stands ∆ age structure of a group of stands ∆ treatment assumption Explore in the field then develop assumptions… or vice versa Plug: typically knowledge gaps – need to support with real data ACE – risky, so “use caution” Nanaimo - February 27, 2014 Coastal Silviculture Committee 24
25
Methods of Influence – by Era Existing Natural Stands Scheduled for harvest over the next ~20 years ∆ age structure of a group of stands (harvest pattern) Few ‘silviculture’ opportunities Existing Regenerated Stands Scheduled for harvest after ~20+ years ∆ age structure of a group of stands Typically incremental silviculture treatments Future Regenerated Stands Scheduled for harvest in ~60+ years ∆ the development pattern of individual stands Typically basic silviculture Nanaimo - February 27, 2014 Coastal Silviculture Committee 25
26
Examples - Site Index and Species Regenerated SI – SIBEC/SIASI is the biggest lever (∆ development pattern) “Use species wisely” (ecologically suited; species adaptation strategies; product values) Simply prorate yields for mixed or multi-layered stands Nanaimo - February 27, 2014 Coastal Silviculture Committee 26
27
Examples - Site Index But beware the “Evils of Averaging”… …for Tactical Planning Nanaimo - February 27, 2014 Coastal Silviculture Committee 27 (Interior example)
28
Examples - Minimum Harvest Age Minimum age at which harvesting is commercially viable Determines merchantable growing stock Criteria: Volume, % CMAI and/or diameter Nanaimo - February 27, 2014 Coastal Silviculture Committee 28 38% 25yrs
29
Examples - Minimum Harvest Age A big lever (∆ treatment assumption) Reducing MHAs also lowers long-term harvest level Easy to model; resolves some issues quickly – but risky… Nanaimo - February 27, 2014 Coastal Silviculture Committee 29
30
Examples – Initial Density Beyond a certain level, initial density has little effect on yield (so it’s not just about TPH) Nanaimo - February 27, 2014 Coastal Silviculture Committee 30
31
Examples – Method (Spatial Patterns) TIPSY uses hybrid of initial density and one of 3 spatial distribution patterns (species dependent) So be careful with regen method Nanaimo - February 27, 2014 Coastal Silviculture Committee 31 Natural Clumped Planted
32
Examples – Stocking Initial density in TIPSY ≠ total or well-spaced stems Ultimately, analysts tweak initial density and regen method/patterns to mimic stocking (considering reports generated at different ages) Are we aiming for maximum site occupancy? (wood quality/value) silviculture surveys results do not provide easy inputs for stand-/forest-level modeling Nanaimo - February 27, 2014 Coastal Silviculture Committee 32
33
EPILOGUE Nanaimo - February 27, 2014 Coastal Silviculture Committee 33
34
TSR vs. Scenario Analysis Timber Supply Review What was/is… Past and current practices Balance uncertainties Periodic AAC implemented immediately Some scenario analysis to support AAC determination Timber Supply Scenario Analysis What if… Forward-looking assumptions Explore possible scenarios Anytime Used to support programs; implemented ONLY after responses are verified (years) Aimed to modify AAC Nanaimo - February 27, 2014 Coastal Silviculture Committee 34
35
What do we know? Access to very good inventories (compared to other locales) Robust stand development models; knowledgeable people; methods for sharing information Array of suitable forest estate models But… How well do our assumptions reflect our existing regenerated stands? Depends where you’re at; forest health impacts Incorporating RESULTS information into forest-level analyses is NOT EASY (including depletion) Nanaimo - February 27, 2014 Coastal Silviculture Committee 35
36
What do we need? Adapt to address climate change, forest health and products – ongoing progress Better GY – mixed species stands Better inventories – young stands But… How good are our predictions of stand development to rotation? Okay on average but treatments are typically required with stands “on the fringes” Nanaimo - February 27, 2014 Coastal Silviculture Committee 36
37
What do we need to know? Information needed to support silviculture assumptions: Treatment criteria, windows, response and cost So… How do we build defensible assumptions for developing timber supply scenarios? Trials? Track the right information? Accounts? Nanaimo - February 27, 2014 Coastal Silviculture Committee 37
38
Many thanks to those whose ideas I’ve borrowed… FAIB (too many to name) Bryce Bancroft Gordon Baskerville Cam Brown Reg Davis Jeremy Hachey Peter Kofoed Bill Kuzmuk Antti Makitalo Colin Mahony Eleanor McWilliams Jeff McWilliams Simon Moreira-Munoz Ed Mulock Stephen Smyrl Jordan Tanz Guillaume Therien Jim Thrower Gordon Weetman Doug Williams Nanaimo - February 27, 2014 Coastal Silviculture Committee 38
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.