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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
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Development of external Regeneration Models for FVS – another wrench in the toolkit Don RobinsonESSA TechnologiesVancouver, Canada
Development History A collaborative effort involving • Alan AgerUmatilla National Forest • Duncan Wilson, Doug Maguire OSU • Nick CrookstonRocky Mountain Research Station • Abdel-Azim ZumrawiBC Ministry of Forests and Range • Valerie LeMay, Peter Marshall UBC • ESSA Technologies Ltd. Vancouver, BC
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 1984INT 161 Ferguson & Crookston 1991INT 279 Ferguson & Carlson 1993INT 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 ES1 BM-FFE-PPE Regeneration BM-FFE-PPE Regeneration System BM-ESTAB Parse user preferences Input P(stocking) Harvesting & thinning Total regen stems Diameter, height growth Number species Growth cycles Mortality P(species x) Regeneration Regen stems species x Crown Summary results Constrain regeneration observations ES2 BM-FFE-PPE Regeneration
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 ES1 PrognosisBC Regeneration PrognosisBC Version 3 (SIBC3) Regeneration System IB-ESTAB Parse user preferences Input RegenerationDB Query database Harvesting & thinning Construct current stand summary Nregeneration stand summaries Diameter, height growth Construct MSN input files X-variables file Y-variables file Growth cycles Mortality Run MSN – user preferences MSN Regeneration RegenerationDB For-use file Fitting stats diagnostic output file Query database Crown Summary results 1- or k- plot regeneration observations Constrain regeneration observations ES2 PrognosisBC Regeneration
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