Introducing Forest Vegetation Simulator
(FVS)
The Forest Vegetation Simulator (FVS; also
known as Prognosis) is an individual-tree, distance-independent
forest stand projection model. The model simulates the growth
and mortality of a sample of a stand's trees, using characteristics
such as species, diameter, height, crown length and relative size.
Key outputs are produced at the individual tree and stand level;
including volume, density, species, diameter, height, annual increment,
and crown length. Because of its internal structure, one of its
great strengths is the ability to simulate complex stands composed
of many species and many ages.
FVS is a powerful tool for forest management.
In addition to its core growth and yield capability, it includes
a powerful language that lets users define rules to schedule and
simulate activities at the stand level. Users can define and implement
almost any type of management system, including planting and regeneration,
pruning, thinning from above or below, thinning by diameter range,
and thinning with or without species retention preferences. These
activities can occur at specific years, intervals, or when user-defined
stand conditions are met. Additionally, a number of forest pest
extensions have been developed and linked to the core growth model
(see links under FVS Extensions at left).
FVS is used widely in the USDA Forest Service
(USFS) and has recently been parameterised for the IDF (Interior
Douglas-fir)
and Interior Cedar Hemlock (ICH) zones
of British Columbia. The Ontario Ministry of
Natural Resources has also begun development of a variant for
southern Ontario. Over 20 regional variants exist in the US, each
parameterised for the growing conditions and important tree species
of the different geographic regions. Interfaces also exist, to
help users import inventory data (or start from bare ground),
perform model runs and display and support analysis of model projections.
ESSA has worked with FVS for over twenty years,
providing a variety of services:
1. Development and support of model extensions
ESSA developed several models through a process involving interdisciplinary
workshops, the creation of prototype models and model documentation,
examination of model behaviour, followed by further testing, refinement,
and preparation of training materials (see links under FVS Extensions
at left).
2. Calibration
of new variants
ESSA is working with the BC Ministry of Forests, the University
of British Columbia, and the Ontario Ministry of Natural Resources
to help calibrate FVS for forests in parts of BC and Ontario.
3. Interface
development and support
ESSA maintains and develops the Canadian
interface to FVS/Prognosis.
4. Custom
simulation runs
Members of ESSA's Forestry Team have performed many thousands
of FVS runs involving numerous variants, pest extensions, and
management objectives. Links to some of these analyses can be
found on the FVS Reports & Publications
page.
Additional Information at Related Sites:
BC
Ministry of Forests PrognosisBC web site
USDA
Forest Service FVS web site
UBC
PrognosisBC web site
FVSOntario web site
