LANDFIRE (LF) calls historic (pre-European settlement) ecosystems "Biophysical Settings," or BpS. To better understand how BpS functioned across the United States, LF worked with hundreds of experts to develop descriptions and models. The results are combined into "sets" or bundles that are available to anyone for free online.
The What and the How of BpS Models
LF used an expert-based development process to create state-and-transition models that describe pre-settlement ecosystem structure and function for every Ecological System present in the current LF BpS. Each ecosystem, which LF calls a Biophysical Setting (BpS), has a description document and a quantitative state-and-transition model including succession/growth and disturbance that can be viewed and manipulated in either the Vegetation Dynamics Development Tool (VDDT) or ST-Sim. LF BpS quantitative models were first developed in an early version of VDDT, but now can be examined and modified in the latest incarnation of VDDT called ST-Sim. ST-Sim represents a significant advance in state-and-transition modeling and its use is strongly encouraged.
LF used the BpS models to estimate reference conditions (sometimes referred to as "Natural Range of Variability" or NRV) for each BpS, which are then used to help evaluate ecosystem health through a departure metric called Vegetation Departure. The document "Using the LF Biophysical Settings Model Descriptions" examines major elements of the BpS descriptions and their uses. In addition, expert-developed models and descriptions are the source of LF's historic fire regime information.
How others use BpS Models
A variety of applications of BpS models have been described in project reports, meeting presentations, posters and journal articles. Examples include: