other+growth+models

Forest Growth Modeling Options
NED

TWIGS

STEMS

HARVEST

SILVAH


 * LANDIS II**

LANDIS-II is a forest landscape simulation model. Forest landscape simulation models estimate forest change over large spatial scale (typically > 10 ha) and longer time scale (> 10 years). Forest landscape models simulate succession (changing species composition) and disturbances. Many landscape forest simulators simulate succession using successional states and transitions. In such models, the forest states are defined a priori and there are a fixed number of states (ranging from 3 - 50). Transitions between successional states are determined by a probability, age, disturbance, or some combination. In contrast, LANDIS-II is an individual species model. The model user defines a number of species and key life history characteristics (or attributes). These attributes determine where and when a species establishes, how long it grows, how it responds to disturbances, etc. Therefore, these attributes determine the successional strategy for each species.


 * PROS:** The benefit of LANDIS II would be that it can include additional information which could potentially be useful, such as forest succession and natural disturbance dynamics (ie. wind, fire, insect outbreaks). Additionally, the utility of LANDIS II is extensible through the use of user-developed extensions, which may be able to incorporate additional detail regarding climate change, carbon cycling, and biomass accumulation (perhaps in the form of course woody debris?).


 * CONS:** LANDIS II may do //too// much - processing and write times may be too expensive, and interfacing with the game language may be more difficult than necessary.


 * FVS**

The Forest Vegetation Simulator (FVS) is a family of forest growth simulation models. It is a system of highly integrated analytical tools that is based upon a body of scientific knowledge developed from decades of natural resources research and experience. Since the development of the first model for northern Idaho in 1973, FVS has evolved into a collection of “variants” which represent different geographic areas across the country. FVS answers questions about how forest vegetation will change in response to natural succession, disturbances, and proposed management actions. Extensions to the base model are available to assess the effects of insects, disease, and fire. The Fire & Fuels Extension (FFE) includes live tree, dead tree, down dead wood and forest floor biomass information, which can be used to estimate changes in carbon stocks over time. A climate-sensitive version known as Climate-FVS is currently available for western states, and an eastern version is in development. Climate-FVS changes core growth, mortality, and regeneration estimates to respond to climate change, according a user-selected general circulation model (GCM), thereby allowing users to model the effects of management under changing climate conditions.


 * PROS:** Powerful, well developed, extensible platform that can provide a high resolution projection of forest dynamics.


 * CONS:** Just as with LANDIS II, FVS may do //too// much - processing and write times may be too expensive, and interfacing with the game language may be more difficult than necessary.