Growth and Yield in Central and Northeastern BC
A meeting held at the University of Northern British Columbia,
Prince George, on 29 June 2005. The objective was to gather a
relatively small number of researchers closely associated with
forest growth modelling, to exchange ideas and information, and
to dicuss research strategies and funding. The meeting was
organized by Valerie LeMay (UBC), with
collaboration from Mike Jull (Aleza Lake Research Forest) and Oscar
Nicole Balliet took care of local arrangements.
|0830 – 0900
||Introductions, Housekeeping, and Outcomes – Oscar
|0900 – 0920
||PrognosisBC work, summary – Abdel-Azim Zumrawi,
Valerie LeMay, Peter Marshall
|0920 – 0940
||MGM – Mike Bokalo
|0940 – 1000
||TASS – George Harper and Catherine Bealle
|1000 – 1020
|1020 – 1040
||SORTIE-ND – David Coates
|1040 – 1100
||Work by CFS – Phil Burton
|1100 – 1120
||SDMDs – Craig Farnden
|1120 – 1140
||NIVMA – Andrea Eastham
|1140 – 1300
|1300 – 1330
||Research Forests, Data, Installations,
Projects – Mike Jull, Melanie Karjala, Sue Grainger,
and Ken Day
|1330 – 1500
||Discussion – recorded/summarized by Val LeMay (and
|1500 – 1520
|1520 – 1600
||Discussion – tasks and who should do them
|1600 – 1630
||Summary by Oscar
- We find out what each other is doing.
- We use this information to help direct our research.
- This might also result in a proposal(s) to NCE (SFM network
out of U of A) for example.
- A summary of the discussion could be posted as meeting
minutes on a web site at UNBC and/or FOREX (see www.forestry.ubc.ca/Prognosis/treelist
as an example of the outcome).
Rasmus Astrup, University of British Columbia – graduate student
Nicole Balliet, University of Northern British Columbia
Adrian Batho, University of Northern British Columbia – graduate student
Catherine Bealle-Statland, Ministry of Forests
Bryan Bogdanski, Canadian Forest Service
Mike Bokalo, University of Alberta
Phil Burton, Canadian Forest Service
David Coates, Ministry of Forests
Ken Day, Research Forest
Andrea Eastham, Industrial Forestry Service
Craig Farnden, Consultant
Oscar Garcia, University of Northern British Columbia
Anthony Giannotti, Industrial Forestry Service
Sue Grainger, Research Forest
George Harper, Ministry of Forests
Zhengjun Hu, University of Northern British Columbia – graduate student
Mike Jull, Research Forest
Melanie Karjala, Research Forest
Val LeMay, University of British Columbia
Peter Marshall, University of British Columbia
John Pousette, University of Northern British Columbia – graduate student
Steve Stearns-Smith, SIGY Co-op
Alan Wiensczyk, FORREX
Abdel-Azim Zumrawi, Ministry of Forests
- Abdel-Azim Zumrawi, Valery LeMay, and Peter Marshall.
PrognosisBC Model and Current Research
(pdf, 761 kB)
- Mike Bokalo, Ken Stadt, Steve Titus, and Phil Comeau.
Mixedwood Growth Model (pdf, 69 Kb)
- Stand Development Modelling Group, BC Ministry of
Forests. Tree and Stand Simulator (TASS) (pdf, 2243
- Dave Coates, Erin Hall, and Rasmus Astrup. Forest
Dynamics Studies in Sub-Boreal Spruce Forests (pdf, 265
- Andrea Eastham. Growth and Yield in Central and
Northeastern BC: NIVMA Update (pdf, 160 Kb)
- Phil Burton. Canadian Forest Service Activities in
Support of Growth & Yield Research in North-Central
B.C. (PowerPoint, 378 Kb)
(Recorded by Nicole Balliet, Valerie LeMay and Alan Wiensczyk)
- Growth and Yield models for the Central Interior,
especially for complex stands (e.g. Cedar/Hemlock; Spruce
- Some stands covered by existing models (e.g., IDF
– covered by Prognosis to some degree; SORTIE –
calibrated in Cedar/Hemlock but not for this region)
- Work is ongoing to extend the PrognosisBC model to the
Sub Boreal Spruce (SBS) zone; most likely for the dw1 and
dw2 subzones as these are the zones with available
- Not much data (PSPs)
- North is data poor and model poor. However, many PSPs
were installed in the early 1990’s with FRBC funding.
- Juvenile Growth:
- All species and BEC zones
- More species in complex stands
- MGM model:
- Improvements made for Aspen – need data to
- White spruce – improvements need to be
- Spatial models better for competitive status measures
(for light, etc) than aspatial models
- For mixed species, need competitive status but also
some knowledge of neighbouring species
- "Random" (not due to competitive status—could be
past competition, other agents, etc.) and senescent
mortality (more susceptible to pathogens, wind, insects)
harder to get at
- Even for TASS, a managed stands, spatial model, there
still a great deal of uncertainty with mortality; recent
work on photosynthetic capability to possibly increase
- Stand level mortality greater certainty than tree level
- SORTIE-ND – new FSP project lead by Rasmus Astrup
working on a mechanistic approach to mortality.
- SORTIE-ND – does a good job on competitive
mortality but hard to get information on random death
– more work needed on senescence mortality and
- Disease and insect caused mortality also difficult to
- PrognosisBC – use individual tree probability of
mortality – use PSP data for that – need to do
more work on this. Clumpiness adds more complication.
- Projects by Dave Coates, Phil Burton, Prognosis team
- Light for regeneration growth:
- use overstory as a surrogate for light for some
models (e.g., Prognosis)
- use average light for some models (e.g., MGM)
- use overstory to estimate light for each tree
- Regeneration establishment:
- MGM not enabled (user-supplied)
- Prognosis (user-supplied or look up table)
- SORTIE predicted by parent tree availability,
substrate, etc, depending on detail available
- MPB Stands:
- need data
- projects happening, co-ordination needed (advance
regen – Phil Burton), chronosequence (Patience
Rakochy and Chris Hawkins, UNBC), Craig Delong (PSPs),
Dave Coates (pine regen post-recruitment), Brad Hawkes
(2 measurements, and other datasets), re-measurement of
old PSPs in SBS proposed.
- Links to landscape, forest level inventories:
- Tree-lists from forest cover
- SELES and other landscape level models – can
connect to GY model
- TIPSY – can run stands that exist
- New equations (e.g., GIS project at UNBC—Phil
- OAFS: Master’s project at U of A to look at what
causes differences between G+Y volumes (yields) and actual
stand volumes; Mike Cruickshank (CFS): looking at OAFS for
Armillaria root disease.
- Must keep in mind that NE and Central BC is not just
MPB-affected pine stands
- Habitat characteristics/stand structure:
- Models have snag recruitment sub-models; not
necessarily calibrated to local areas
- Some features (e.g., loose bark, internal decay) are
hard to model
- Could add model outputs that give information for
habitat (e.g., tree class codes, etc.)
- Model architecture should be such that submodels can be
added for a particular purpose – most models have
- SORTIE-ND – working fall rates for snags and on
sorting out how snags affect light transmission in
- A lot of snags and trees with good wildlife attributes
are not from competition induced mortality but from
senescence mortality which is very difficult to model.
- Modeling and reporting uncertainty:
- From the model perspective — not possible with
the complexity of these models — too many
- Compare model outcomes to actual values
- Stochastic model components: report either averages
(e.g., PrognosisBC) or ranges
- Sensitivity analysis of input variables
- Model certainty will depend upon data used to derive
- Many model users have different expectations around
models and what they can and cannot do. It is important to
remember that there isn’t necessarily any one
‘right’ answer but rather there is a
‘right’ range with probabilities. Maybe
modelers need to put confidence limits on yield
- Methods, data, approaches differ depending on modeling
group, even though the group is working on the same problem:
- Need to collaborate on data sharing where possible
- Forms are available for people doing field work to
collect small tree data to help with calibration and
testing of PrognosisBC model.
- Would be useful for people to have data forms
beforehand so that those collecting field data can see what
needs to be done when planning field work.
- Data collected and used are often specific to the
modeling approach and problem addressed
- Different models more suitable for different problems;
one model will not solve all problems
- Documentation of models is needed: need a set of
Working Papers? Or another outlet source?
- Data gaps:
- Funding drives data availability – use what is
available, or sample only particular stands (e.g., mesic
sites, sites of interest (NIVMA))
- Objectives of individual projects differ and therefore,
data protocol differs.
- Documentation of available data (e.g., MPB-data –
- Canadian Forest Service has long term silviculture
trials – especially for Pli in Alberta, although some
in BC as well. Also have mixed-wood management sites
– EMEND, Hotchkiss Creek and Alcott Creek –
some potential data sources.
- Various Research Forests – Alex Fraser, John
Prince, Aleza Lake – have established PSPs.
- Validation of models
- Need PSPs
- DBH minimum limit changes over time
- Hard to get the data you need, unless you know that
database (e.g., need regeneration and tree data, but can
only get the tree data)
- Non-PSP data – cannot connect time sequence
- Forest health data for monitoring post-disturbance, may
be a source of info for regeneration modeling
- Need more portability (of data and models) and transparency
of inputs into models:
- Need more documentation for this to occur
- Also need a central registry
- Some of this is happening, e.g. EP Data via Forest
Science, and Inventory PSPs
- have to overcome competition (between models). No
single model will address everyone’s needs –
that’s why we need a suite of models.
- Source of data can be influenced by source of funding
which can influence the model
- Most models use mesic sites - How do you quantify and
transfer info from mesic sites to other site types?
- Need to collaborate (talk) on some projects now going
forward e.g., regeneration following MPB – much of this
is taking place in Central and NE BC, between CFS, UNBC,
- Intellectual property – when to make models public
and in what form?
- Do we need to keep maintaining and measuring the PSPs plots
on the Research Forests? Aleza Lake has over 200 plots, some
going back 80 years. There are questions as to which ones are
still useful and should be re-measured and which ones should be
abandoned. How do you determine the value of the data sets?
Maintaining funding for PSPs difficult – need to keep the
political will up.
- Long-term data:
- Profile is low – why?
- PSPs owned by agency that doesn’t use the
datasets much? Need to market the database? Cataloguing?
- EP’s – no permanent funding for these
- Funding agencies only fund if linked to a research
projects with outcomes that will appear soon.
Re-measurement of PSPs isn’t seen as research even
though the data can be used for research.
- Inclusion of PSP re-measurement in a research project
can make the budget for the project too large and result in
funding being denied.
- Can’t agree on core matrix of plots that need to
- At meeting, noted that papers and reports must come
regularly for continued funding of PSPs
- At research forests, DO get funding by linking
re-measurement of PSPs to a specific research project
(e.g., Master’s project)
- Problem with this – end up with sporadic,
installation specific measures – large gaps in
- From a modeling perspective, hard to use existing PSP
data because of different measurement protocols over time
(e.g., minimum dbh); often very little juvenile data
- Must adapt methods to measurements that exist
- Valuing of plots – difficult as this changes over
time, and costs are very high
- NE and Central BC – low amount of data?
- In the US they have one person responsible for
producing specific outputs/publications each year that uses
the data from PSPs. This helps to maintain funding and
interest in these plots.
- Who is funding research?
- Letter to FSP Volume and Value regarding priorities for
Central and NE BC?
- FSP funding model trying to get something similar Tree
What should we do?
- Mortality modeling meeting – (e.g., electronic
discussion? One-day workshop at UNBC?)
- Extension/user meetings relating to Mountain pine beetle
and growth and yield – Steve Stearns-Smith (SIGY) and Al
- Documentation of models is needed on websites and/or within
help sections of models
- Documentation of data will promote sharing
- MPB – Will collaborate more on this for better
models/use of funds and data
- MPB – Plan to re-measure PSP’s in MPB affected
areas. Would like researchers to look at re-measurement
protocols for regeneration and let PSP coordinator (Bob
Macdonald) know if sufficient for use in development of models.
Existing protocols are available on the web.
- Letter to FSP Volume and Value regarding priorities for
Central and NE BC?
- This year (2005-06), SIGY is championing creation of a provincial
organization to provide G&Y guidance and funding coordination similar to the
Forest Genetics Council and FIA Tree Improvement Program. Strategic
linkages with FIA's Forest Science Program and the provincial inventory
program are also being explored.
- Article on GY needs for Central and NE BC for Link Funding
Proposal Topics and Possible Leaders
- JEM (BC Journal of Ecosystems and Management): Article to
increase profile of long-term PSP data
- NCE proposals? Email around to see who is interested
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