This document provides an introduction to modeling forest dynamics. It discusses different types of forest models including tree stand models that operate over 10-50 years and landscape models that operate over 50-100 years. It also summarizes various approaches to modeling including process-based models, empirical growth models, stand models with and without diameter distributions, individual tree models, gap models, and landscape models. The document concludes by discussing tools for visualization of forest modeling results and the aims of a training course on the Forest Vegetation Simulator (FVS) model.

1. INTRODUCTION TO MODELING FOREST DYNAMICS
Giorgio Vacchiano – Dip.AgroSelviTer, Università di Torino
giorgio.vacchiano@unito.it

2. Forest dynamics models
Tree Stand Landscape
5-10 yrs 10-50 yrs 50-100 years

3. 1896
now
????future

4. Process
-based
models
Empirical
growth
models
Incorporation of knowledge about the
physiological processes
Flexibility and extrapolation ability
Demandofinput
Complexity/Scale-1
Stand models
without DBH
distribution
Stand models with
DBH distribution
Individual tree models
distance independent
Individual tree models
distance dependent
Physiological
models
Gap models

5. Process
-based
models
Empirical
growth
models
Incorporation of knowledge about the
physiological processes
Flexibility and extrapolation ability
Demandofinput
Complexity/Scale-1
Stand models
without DBH
distribution
Stand models with
DBH distribution
Individual tree models
distance independent
Individual tree models
distance dependent
Physiological
models
Gap models

6. Yield tables

7. Growth equations
Altezza dominante Incremento

8. Density Management Diagrams
Density
Meansize(diameter,volume)
Even-aged
Monospecific

9. Individual tree models

10. How to grow a tree (with a computer)
1. Estimate potential tree growth with no
competition
2. Modify potential growth with some
competition index
3. Estimate probability of tree death
4. Update the tree’s diameter and number
of live trees per hectare from equations
25

11. Individual tree models
 DBH increment = f (size, competition, site)
 Mortality (%) = F (size, competition, site)
 Ingrowth (trees/ha) = F (competition, site)
 Height (m) = F (size, site) or
 Height increment (size, competition, site)
26
Uneven-aged
Multispecies

12. 27

13. 28

14. Distance independent
 Tree list
 Stand list
 Site parameters
 Simulation tasks

15. 30

16. SILVA

17. Landscape models (grid)

18. 36
LANDIS Operational Design
climate zone
soil map
DEM
Multiple fire regimes: Ignition, size,
cycle, spread, intensity and severity
multiple species and
age input maps
output single
species map
year 0
year n
reclassified
vegetation type
output
disturbances
species age
Classes
model input
model simulation processes
Environmental boundaries
and constrains
Site and species interactions
succession, seeding, disturbance
history, and disturbance interaction
Harvest prescriptions: stands,
management units, rotation
size, species, and methods
fire
wind
harvest
Land type
Insect/disease
fuel
Fine, coarse and life fuel
Accumulation/decomposition
Wind regimes: size, cycle,
spread, intensity and severity
Epicenter, frequency, size,
Hosts, susceptibility,
intensity, and severity

19. LANDIS model
 Generic framework for simulating landscape change in
response to disturbance
 Scaleable pixel size (10m to 1,000m)
 Tracks presence/absence and bipmass of tree species
on each pixel by age and location
 Must be calibrated for local forest conditions
 Simulates stochastic fire and wind events
 Harvest simulator
37

20. Visualization
 Geometric modeling
CAD and dedicated software
 Video imaging
Photoshop
 Image draping
GIS - Geographic Information Systems

21. Geometric modeling

23. Image draping

24. Image draping: EnVision

26. Visual Nature Studio

27. Stand dynamics models
 Inventory update
 Timber production (growth an yield)
 Effect of silvicultural practices
 Natural disturbances and hazards
 Effect of limate change
Communicate (eg, visual)
Simplify Forecast Scenario

28. FVS training course: aims
Foresters:
 Familiarize with available tools
 Verify usability
 Enlarge professional network
Researchers:
 Verify users’ needs
 Obtain directions for model
development

29. FVS training course: teachers
Dott. Giustino Tonon – UniBZ
Dott. Giorgio Vacchiano – UniTO
Prof. James N. Long – Utah State University
Dott. Enno Uhl – Tecnische Universitaet Muenchen
Talks
Guided activities
Group activities
Individual activities

30. FVS training course: program (1)
9.00 Registration, welcome address, members’ self-introduction
9.45 Introduction to modeling forest dynamics
10.30 Key concepts
11.00 Stand average models
---
11.45 Introduction to FVS and species
12.00 Silvicultural prescriptions and management objectives
12.30 Setting up a simulation in FVS
---
14.30 Running FVS simulations
15.00 Interpret and customize simulation results
15.45 A further look at the output
---
16.45 The Stand Visualization System (SVS)
17.45 Options of SVS
18.15 Introducing the fire and fuel extension (FFE) of FVS

31. FVS training course: program (2)
Day 2
9.00 Review of day 1
9.10 Running FFE simulations, customize fire management
10.20 An introduction to SILVA
---
11.40 Scenario modeling with SILVA (part 1)
---
14.30 Scenario modeling with SILVA (part 2)
15.15 Presentation of scenario results, in groups
15.45 Final discussion and wrap-up
C:FVSBIN
C:WORKSHOP

32. Handouts
 List of participants
 Activities
 Evaluation forms
 Unit conversions
 Species and stand descriptions
 Silvicultural glossary
 Topics for final discussion
 List of readings and links
 Presentation overheads
 …