R and the Forest Vegetation Simulator Interfacing an old school model with R MASON EARLES D-RUG 02.13.13

What’s the forest vegetation simulator (FVS)? What did I want to do with it? Where does R fit in?

What’s FVS? Models forest growth, mortality and fire

What’s FVS?

- Developed and commonly used by US Forest Service - FORTRAN language - Empirically based growth/mortality

- Individual trees modeled

- Tree interactions affect growth and mortality

My goal: Use FVS ‘Monte Carlo style’ with stochastic fire and drought events

Problem: I don’t know the FORTRAN language; FVS is a mess of code maintained by a couple of people

But I know R!

Open-FVS = publicly available source code…API linking FVS to R

FVS can now be run from R!

A few things I’ve done with linked R + FVS

Batch modify keyword code files w/ R

Keyword file

Stochastic fire events

Burn probability = 40 years

%dopar% for parallel simulations

Stochastic drought events

Similar approach for drought events

Simulation Examples: #runs = 100