development of external regeneration models for fvs – another wrench in the toolkit
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Development of external Regeneration Models for FVS – another wrench in the toolkit. Don Robinson ESSA Technologies Vancouver, Canada. Development History. A collaborative effort involving. Alan Ager Umatilla National Forest Duncan Wilson, Doug Maguire OSU - PowerPoint PPT PresentationTRANSCRIPT
Development of external Regeneration Models for FVS –
another wrench in the toolkit
Don RobinsonESSA TechnologiesVancouver, Canada
Development History
• Alan Ager Umatilla National Forest
• Duncan Wilson, Doug Maguire OSU
• Nick Crookston Rocky Mountain Research Station
• Abdel-Azim Zumrawi BC Ministry of Forests and Range
• Valerie LeMay, Peter Marshall UBC
• ESSA Technologies Ltd. Vancouver, BC
A collaborative effort involving
Have you noticed…
Despite over 30 years of development, new extensions and variants, there are very few full-featured regeneration models in FVS
Ferguson, Stage & Boyd 1986 For. Sci. Ferguson & Crookston 1984 INT 161 Ferguson & Crookston 1991 INT 279 Ferguson & Carlson 1993 INT 467
Why is that?
Regeneration is a Hard Problem
• Inventory measured on-the-ground, not remotely• Can require numerous samples (12,000 :: 500)
• Disturbances may be slow, history may be fuzzy• Regen cues may be subtle, fine-scale, site specific• Regen may be delayed or stutter unevenly
Conceptual model development takes time
Who Cares Anyway?
Past- emphasis on predicting timber values over single
rotation
Present – the times, they are a changing
- multiple ecosystem values- natural disturbances: insects, fire, disease- longer time periods
Future – the times, they are a changing; again
- complex, largely unknown relationships between climate, trees, disturbance, invasive species …
What Are The Options?
1. Simple Manual
You are the all knowing expert: thin and plant
What Are The Options?
2. Logical Conditions
You understand rules governing what will happen
What Are The Options?
3. Complex rules
You use the Event Monitor to create a complex model
Duncan Wilson & Doug Maguire, OSU (2002)
• mimics Ferguson model: habitat types, site effects, level of disturbance; P(stocking), P(species x); predicts seedlings/ac
• implemented through Event Monitor keywords• >950 keyword lines for each stand in PPE• very hard to debug
A New Approach
4. Create a “non-FVS” external model and use FVS to run it
• To drive the external model, create a new keyword in the Establishment family – AddTrees
• Text files pass information each way – ES1, ES2• Simplifies and localizes changes to FVS code• External model can be in any language; could be a
batch file, web-service, R-script …• 2 examples …
A New Approach – Ex 1
Logistic-probabilistic model (Wilson & Maguire)
Patterned after the Ferguson model … predicts seedlings/ac• habitat types• site effects• intensity of harvest disturbance
A New Approach – Ex 1
Input
Harvesting & thinning
Diameter, height growth
Mortality
Regeneration
Crown
Summary results
Parse user preferences
P(stocking)
Total regen stems
Number species
P(species x)
Regen stems species x
Constrain regeneration observations
Growthcycles
BM-FFE-PPE
BM-FFE-PPE Regeneration
Regeneration SystemBM-ESTAB
BM-FFE-PPE Regeneration ES1
ES2
A New Approach – Ex 1
0 – years delay after Condition becomes true5 – years delay to schedule the activities (planting)1 – flag to indicate which set of information to pass
–
A New Approach – Ex 1
*.ES1 – from FVS out to the external model
–
A New Approach – Ex 1
*.ES2 – from the external model back to FVS
–
• uses pre-existing FVS code to process activity schedules
• 431 = NATURAL planting keyword … other values are the usual fields: date, species, stems/ac, etc.
A New Approach – Ex 2
MSN – Regeneration database model(LeMay, Marshall, Zumrawi, Hassani, Froese, Lee, Lencar, Froese, Boisvenue)
• compare simulated stand after disturbance against a database of regeneration observed in actual disturbed stands
• canonical selection of closest match• assign matching stand’s regeneration• currently >1,000 sites, >36,000 regen measurements (2006)
A New Approach – Ex 2
Input
Harvesting & thinning
Diameter, height growth
Mortality
Regeneration
Crown
Summary results
Parse user preferences
Query database
Construct current stand summary
Construct MSN input files
Run MSN – user preferences
Query database
Constrain regeneration observations
X-variables file
Y-variables file
MSN
For-use file
Fitting stats diagnostic output file
RegenerationDB
Growthcycles
PrognosisBC Version 3(SIBC3)
N regeneration
stand summaries
1- or k- plot regenerationobservations
PrognosisBC Regeneration
RegenerationDB
Regeneration SystemIB-ESTAB
PrognosisBC Regeneration ES1
ES2
A New Approach – Ex 2
• slope position and site preparation• 0 – years delay to schedule the activities (planting)• 2 – flag to indicate which set of information to pass• program to call and arguments: location of db, location of
MSN, distance algorithm to use
–
A New Approach – Ex 2
MSN input files are automatically generated and run; output files parsed; database is re-queried and results returned to FVS
A New Approach – Ex 2
Challenges …
• Reconciliation of stand structure of selected stand with ‘known’ structure of modeled stand
• Change in stand structure between disturbance and later overstory inventory (snags, falldown, growth)
• Research team now looking for better prediction approaches … perhaps through linkage to a detailed process model that is sensitive to fine structure in the stand
Challenges :: Opportunities
• Simpler models may gloss over details
• Development of conceptual models will always be iterative and messy
• Conceptual and empirical models are mutually dependent … what to measure, how to measure, when to measure
• Empirical models will still require substantial field work and validation
Challenges :: Opportunities
• Interface between FVS and regeneration models is simple to create and requires only minor code changes in one file
• External regen model specs also modest – any program in any language that reads an input file of FVS state information and returns a file of planting (or other) activities in the expected format
• Prototyping is simple … FVS not required