Project Title: Development and Delivery of the Fire and Fuels Extension to the Forest Vegetation Simulator for use by Stakeholders to the Joint Fire Science Program

Principal Investigators and Affiliations:

Nicholas L. Crookston, Rocky Mountain Research Station, Moscow, ID.

Elizabeth Reinhardt, Rocky Mountain Research Station, Missoula, MT.

Sarah Beukema, ESSA Technologies, Vancouver, BC.

Werner Kurz, ESSA Technologies, Vancouver, BC.

Co-investigators and Affiliations:

Colin Hardy, Rocky Mountain Research Station, Missoula, MT.

Marc Wiitala, Pacific Southwest Research Station, located in Portland, OR.

Robert J. McGaughey, Pacific Northwest Research Station, Seattle, WA.

Jane Kapler Smith, Rocky Mountain Research Station, Missoula, MT.

Address: Rocky Mountain Research Station, 1221 South Main, Moscow, ID 83843

Telephone/Facsimile Numbers: (208) 883-2317; FAX: (208) 883-2318

E-mail: ncrookston/rmrs_moscow@fs.fed.us

Duration of Project: 2 years

Annual Funding Requested from the Joint Fire Science Program: $194,130; $203,065

Total Funding Requested from the Joint Fire Science Program: $397,195

Authorized signature:

____________________________________

Director, Rocky Mountain Research Station

Abstract-The Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) can be used to evaluate wildland fuels treatments alternatives and schedules (tasks 1 and 3) and can aid in social understanding and acceptance of different fuel treatments (task 2), especially when used in conjunction with visualization software. This proposal seeks funds to continue the development and delivery of FFE-FVS to cover the most disparate woodland and timberlands in the western United States. Individual tasks include the calibration of regional variants; publication of documentation; redesign of FVS and some associated pest extensions to better represent the interactions between insects, diseases, fuel dynamics, and fire; enhancement of the Suppose graphical user interface to support FFE-FVS; enhancement of existing visualization software to represent fuels and fire; assessment of the visualization's effectiveness in education and public forums; user training; and continued interaction with JFSP stakeholders to ensure that FFE-FVS is meeting users needs and can be used cooperatively with other tools as necessary to meet the JFSP objectives. Extension of this work to the eastern U.S. is advocated for future funding. Cost estimates are provided by task thereby providing JFSP management an opportunity to select among tasks for funding.

Introduction

1) Project Justification.

Central goals of the Joint Fire Science Program (JFSP) are to provide tools necessary to analyze alternative fuel treatment strategies and schedules, including letting nature taking its course. These tools must provide consistent methods applicable to all stakeholders, and operate over the range of wildland ecosystems including grasslands, ranges, shrubs, woodlands and forests. Key variables include those that determine the effects of smoke production and distribution on air quality and those used to characterize the structure, function, and composition of the ecosystems. The tools must represent key ecosystem components central to trade-off analyses, including interactions with insects and diseases.

Science can contribute to attainment of these goals by providing the means to display consequences of proposed management actions, whether no action, fuels treatments, prescribed burning, thinning, or an innovative combination of management actions. This will require an interacting collection of models that individually accomplish some of the goals. Existing models will need to be modified and combined to address the central goals as a set. If some parts of the overall goals are not covered by currently available components, then these gaps need to be identified and filled.

Last year, we proposed that the Fire and Fuels Extension (FFE, Beukema and others 1997, Beukema and others 1999) to the Forest Vegetation Simulator (FVS, Stage 1973, Wykoff and others 1982, Wykoff 1986) be identified as one key tool useful in this overall set. We received JFSP funding to ensure that this tool will work with others needed to meet the overall system requirements and to demonstrate the usefulness of FFE-FVS to meet some key JFSP objectives.

One of the key accomplishments from the first year's work is the report from a workshop titled "Decision Support Needs of the JFSP Stakeholders and the Role of the Fire and Fuel Extension to FVS" (herein called the Seattle workshop, Kurz and Beukema 1999). The outcomes of this workshop largely motivate this proposal. Workshop participants represented most agencies of the JFSP and came from a broad geographic reach. Several disciplines, including fuels and fire management, silviculture, economics, ecology, wildlife management, pathology, and entomology were represented. The workshop report documents the capabilities required of the FFE-FVS to support fuel management decisions and how and in what situations it should interact with other tools. During the workshop, these JFSP stakeholders were asked to state their needs, the roles existing tools play in meeting those needs, and how the tools can interact. It was within the context of this broad information that the changes required of FFE-FVS were revealed. Meeting those needs is the objective of this proposal and the justification for funding the work.

Specific relationships to each task in the Request of Proposals are as follows:

Relationship to task 1: "Compare or model economic impacts in order to evaluate wildland fuels treatments or planning processes."

FFE-FVS combines fuels dynamics and fire behavior with the FVS system. FVS is widely used by silviculturists, forest planners, and pest managers to predict the effects of proposed treatments on forest composition, structure, and function. Linkages exist between FVS and planning models and economic analysis models (see Teck and others 1997 for examples). By enhancing the linkages of FVS to these models to accommodate inclusion of fuel management activities and costs, FFE-FVS can be used to support economic analyses. In addition, during FY99, work has been funded by the JFSP to provide direct links of FFE-FVS to a stand level economic evaluation package called CHEAPOII (Horn and others 1986) and the suppression resource allocation tool called IASELECT (Wiitala 1992).

Relationship to task 2: "Evaluate social understanding and acceptance of different fuel treatments, and approaches to include social considerations into planning processes."

FFE-FVS outputs, combined with graphics and other data visualization tools (fig. 1 (not include in html version)), can greatly enhance the understanding and acceptance of proposed management actions. The model can represent a wide array of fuel treatments and outcomes and provide outputs suitable to render useful visualizations. Our proposal calls for funding to improve the system's ability to produce outputs used by visualization tools, to evaluate of the tools to ensure they are appropriately tailored for use in public and educational forums, and to write guidelines for their use.

Relationship to task 3: "Develop, evaluate, or compare methods or approaches to incorporate wildland fuels management information into landscape scale land use and planning processes."

While FFE-FVS is a stand model, it can be run concurrently over several to a couple of thousand stands (again, see examples in Teck and others 1997). The Suppose (Crookston 1997) interface to FVS is designed to prepare simulations of this size and managing the outputs and setting of management actions. The outputs of this model form the inputs to planning models and landscape level assessments. The proposal calls for modest funding to improve the current support for FFE-FVS in Suppose and to continue work to ensure proper linkages to landscape-level analysis tools.

Relationship to task 4: "Projects that require rapid response to obtain critical fuel management-related information following multiple or large-scale fire incidents."

None.

2) Project Objectives.

This proposal seeks funds to:

• continue the development and delivery of FFE-FVS to cover the woodlands and forest lands in the western United States;
• to provide for the interaction between fire, fuels, insects, and diseases;
• to improve visualization software so that users can better understand model behavior, applications, and outputs;
• ensure that FFE-FVS is meeting users' needs and can be used cooperatively with other tools as necessary to meet broader JFSP objects, including economic analysis and planning processes.

Our understanding of stakeholder priorities indicates that the extension of this work to the eastern U.S. should be scheduled after we have made significant progress in the west. In the meantime, we will create and maintain relationships with stakeholders and scientists working the east. See the "Deliverables" section for a detailed list of project elements.

3) Background.

What we have-There is extensive experience with FVS among many agencies included in the JFSP (including the Forest Service, the Bureau of Indian Affairs, and the Bureau of Land Management), and FVS has proven useful to private companies, state, tribal, provincial (B.C.), and federal government agencies as an element in preparing forest plans and justifying treatment schedules of forested lands. Support, training, and maintenance activities are provided by the Forest Management Service Center (FMSC) to the federal government agencies and others. Extensions to FVS exist that represent several insect pests and diseases such as bark beetles, Douglas-fir tussock moth, western spruce budworm, mistletoe, and three western root diseases (Teck and others 1996). These extensions are supported by the Forest Health Technology Enterprise Team, State and Private Forestry, co-located with FMSC at Ft. Collins. In addition, FVS has been linked to a variety of economic analysis tools. A graphical user interface (Crookston 1997) is available, linkages to inventory data are established, and the use of FVS with GIS systems is common.

Work on FFE-FVS began in December 1993 when James K. Brown (then project leader of the Fire Effects research unit at the Fire Science Laboratory in Missoula, MT) met with Elizabeth D. Reinhardt, Colin Hardy, Albert R. Stage (then Project Leader of the quantitative analysis unit at the Forestry Sciences Laboratory in Moscow, ID), and Nicholas L. Crookston. The group recognized that fire is an integral part of forest ecosystem function and management and that by linking FVS to models that represent fuels, fire, and fire effects, a model capable of representing fire in forest ecosystems could be produced. To accomplish this work, the original group of scientists contracted a team of modelers from ESSA Technologies to conduct a series of workshops and build the model.

The workshops ensured that the model would provide model outputs that are relevant to users and that the internal components were based on the best available science. Participants included experts in vegetation modeling, vegetation management, snag dynamics, decomposition, wildlife management, fuels modeling, fire behavior, and fire effects. Subsequent work has included adding a torching and crowning component to better model potential for extreme fire behavior. The workshop facilitation and model building methods used by ESSA Technologies were key to the project's successful completion.

Management actions represented in FFE-FVS include prescribed fire, mechanical fuel treatments, a full range of silvicultural treatments, and an array of harvest methods. Wildfires can also be simulated. Outputs show, over time, predicted fuel loadings, stand structure and composition including snags, and potential fire behavior, including indices of crown fire risk.

FFE-FVS was initially calibrated for the Northern Idaho and Western Montana variant of FVS (fig. 2, not included in html version). Calibration of FFE-FVS to represent the drier forest lands in Southern Oregon and Northern California (SO in fig. 2) is scheduled for Spring of 1999.

What is needed-Several areas are work for the next two years are identified. See the deliverables section for an explicit list of what we intend to produce.

The most important need is to calibrate FFE-FVS to more of the areas represented by FVS. We propose to link and calibrate the FFE-FVS to at least six more variants over the next two years.

The need to create appropriate linkages between insects, diseases, fuels and fire within the FVS system was voiced at the Seattle workshop. The current FVS program models these ecosystem components separately and without provision to represent processes that interact or an annual, or more frequent time steps. Furthermore, the current interaction occurs on 5- or 10-year time steps and does not reflect the nature of the interactions. For example, in the model, trees killed by a bark beetle are lumped with those killed by root disease, yet the decomposition rates for trees killed by these two agents may be different.

Enhancement of the Stand Visualization System (SVS, McGaughey 1997) so that it presents an honest and complete representation of the FFE-FVS's state variables and behavior over time is listed as a deliverable. Currently, this software can be used to display a drawing of the trees in a stand. It can also be used to draw a sequence of pictures that show a fire front moving through the stand and the fire's effects. This tool has been used effectively in public forums and in educational settings. However, the software does not render shrub composition, long-standing snags, nor fuel bed characteristics. This limitation is partly due to SVS and partly due to FFE-FVS.

Using proper techniques that combine the use of models and visualizations in public and educational forums can increase the social understanding and acceptance of the models and the treatments they portray. Guidelines as to how to use these tools need to be developed to improve their application. Testing of and usefulness of the software is also desirable.

The Seattle workshop proved to be a useful forum for the FFE-FVS modeling team, users, and other scientists and modelers. Not all tools available for stakeholder use were considered at the workshop. In some cases, one or two models were picked to represent classes of models. This approach provided enough information to address FFE-FVS-related issues. Interest holding a similar workshop at a later date and with a group that represents a wider array of tools used by JFSP stakeholders was voiced at the workshop. The additional workshop would benefit the FFE-FVS development team by revealing any new, additional requirements and it would document the relationships between a wider set of tools that together are used to meet JFSP objectives. This information would serve the JFSP board by pointing out gaps and overlaps in the technologies. Therefore, we propose to host another workshop during FY2001.

During the Seattle workshop we were told that stumps are a major contributor to smoke production (Roger Ottmar, personal communication). We propose to modify FFE-FVS so that it can track the creation of stumps through harvesting and tree mortality, and stump decomposition. This addition to FFE-FVS will enhance the model's predictions of smoke production.

In the long run, routine maintenance will be provided by the FMSC. However, during the development of FFE-FVS and its regional variants, the cost of maintenance and making routine changes to ensure its usefulness is much higher than normal. For this reason, we are asking for modest maintenance funds.

User training is a typical part of technology transfer. Therefore, our deliverables section lists presentation of two training workshops done in conjunction with basic FVS training.

The work proposed for FY99 included an element to build a prototypical way to represent wildland types outside the range of FVS as it is limited to woodlands and forests. By the date of this research proposal, we have not completed this prototype model. However, we have identified an approach that will likely work and serve the stakeholders needs. That approach is to adapt a low resolution succession model like the one used in the Interior Columbia River Basin Assessment (CRBSUM, Keane and others 1996) for use within FFE-FVS. CRBSUM represents successional pathways between plant communities growing at a specific site. The potential vegetation type and geographical location are used to select a set of pathways, disturbances, and probabilities of disturbance occurrence.

While this approach will likely work, and thereby extend FVS to represent non-forested ecosystems, we believe that it is unnecessary to build this capability into FVS at this time. FFE-FVS does represent the non-tree vegetation in the predictions of fire behavior. This is particularly important in woodland and forest types where fire behavior is largely driven by shrub vegetation. While the techniques used in FFE-FVS to represent non-tree vegetation are simple, have tentatively concluded that they are adequate for the purposes. This conclusion may prove incorrect. A more detailed approach may be needed in some parts of the country and not in other parts.

One of the initial reasons for trying to represent grass and shrub types was that by adding that capability to FFE-FVS, the system could be extended to model fire spread among stands within a landscape. This could be done by linking FFE-FVS to the Parallel Processing Extension of FVS (Crookston and Stage 1991). If FFE-FVS were to model such spread, then it would need to be able to represent non-forest sites. However, for the time being, it is not necessary to model fire spread over the landscape using FFE-FVS because FARSITE (Finney 1998) is designed for this purpose and can be initialized with fuel information for forested sites by running FFE-FVS. By using the two models together, and others that represent non-forest sites, FARSITE can be used to simulate the effects fuel treatments applied at arbitrary points in time and space have on landscape-level fires.

Materials and Methods

To build a new regional variant, we start by holding a small workshop with representatives from the region. Workshop notes are written and the regional variant is programmed. A follow up workshop is held to demonstrate the variant's behavior, to identify poor behavior, and to make appropriate adjustments. The model is then released in test mode for further user evaluation and testing. The programming and scientific team also test and evaluate the model's behavior. The model is found ready for general use when the core users and scientists find it useful and programmatically stable. A summary of the variant content and behavior is prepared and added to the available documentation.

Some of the regional variants will require more effort than others. For example, we anticipate that the Western Sierra (WS, fig. 2 not included in html version) and Central Rockies (CR) variants may require more work, particularly in the fuels dynamics submodels, than will be required to create the Eastern Montana (EM) variant. Variants like the EM, and the Central Idaho (CI) variants are largely based on the North Idaho variant and therefore they will require less work than the WS and CR. In general, the base FVS system variants can be grouped. Creating FFE variants within a group will be less work than creating those between groups. We specifically included WS and CR in this proposal as they, with NI, represent 3 very different cases. Getting those done will likely make the others easier.

Linkages between FFE-FVS and other tools, like regional landscape analysis tools, other fire tools, and so on, are created as the need is shown. This work usually is requires modest changes to the computer program and documentation and is accomplished along with other maintenance work.

To ensure that FFE-FVS contains needed linkages to other tools, we will host a workshop that has a larger scope than Seattle workshop. In that session, we will review the stakeholder needs, available tools, and the interaction between tools. A report similar to the Kurz and Beukema (1999) workshop report will be prepared. Modest changes needed in FFE-FVS that are discovered through this workshop will be made as part of regular model maintenance activities while more substantial changes may require addition funding.

To improve the visualization software, we will modify FVS to directly track the location of trees over time. The location of snags will be tracked and a link made to the FFE-FVS's ability to model their decomposition and fall down. Significant down snags will also be tracked and output to the SVS software. To properly portray the fuel bed, a set of translucent bitmaps will be created by scanning photographs in the fuel photo series. FFE-FVS will output information to SVS useful in selecting the mix of translucent bitmaps to use in drawing a realistic fuel bed. The large down snags and standing trees (alive and dead) will then be added to the picture.

To prepare guidelines for using FFE-FVS visualizations (year 1), we will review literature on the use of mathematical models and visualizations in public involvement and education; interview communicators who have used technology similar to that of FFE-FVS and SVS; and prepare a short report that summarizes our findings and recommendations. To test the effectiveness of FFE-FVS as conveyed through SVS (year 2), we will collaborate with Forest staff who are using the model. We will assess perceptions of students or members of the public before and after exposure to model results and visualizations. We will analyze these findings and information in the literature, then recommend effective ways to present the modeling process and model results in educational and public involvement programs.

Project Duration

2 years. A follow-on proposal to work with the Eastern United States is planned but not included in this proposal.

Budget

This budget assumes that all of the items listed under Deliverables are desired by the JFSP. If some items are not desired, and the proposal is therefore only partly funded, the PI's will make appropriate changes in the distribution of funds among budget line items.

Deliverables

Approximate costs are listed with each deliverable. These costs include overhead charges. Delivery of all items is contingent upon securing necessary procurement and technical approvals which will be diligently pursued.

At least six new FFE-FVS variants including these 2: Western Sierra Nevada Mountains of California (area marked WS in fig. 2, not included in html version), and the area covered by the Central Rocky Mountains variant (forests of New Mexico, Arizona, Colorado, and the Black Hills of Wyoming, and small parts of western South Dakota, and Nebraska, the area marked CR in fig. 2, not included in html version). The others will be determined during the life of the project. Variant development includes preparation and delivery of documentation, including documentation of model behavior, and delivery of the software via the Internet. Approximate cost per variant: $30,000, total $180,000; delivery of 3 per FY.

Support for FFE-FVS in the Suppose interface that is similar to the support provided other extensions to FVS. This will include support of all FFE-FVS model commands and the ability to build custom reports, averages, and graphics for all data contained in the All Fuels Report and the Potential Fire report. Other reports may be included. Customized support for regional variants of FFE-FVS will be developed as needed. Suppose is currently available via the Internet and support and training are available. Approximate cost: $12,000 over 2 years; delivery as changes are made to coincide with the delivery of variants of FFE-FVS.

Publication of model documentation and user's guide. The model description has been drafted and funding is in place to draft the user's guide (from sources outside the JFSP). This proposal requests money to cover publication costs and consultants time to finish revisions prompted by peer review. Approximate cost: $14,700; delivery in FY2000.

Redesign of the FFE-FVS, the base FVS, and three pest extensions to better represent the interactions between insects, diseases, fuel dynamics, and fire. The pest extensions we plan to address are the Western Spruce Budworm (Sheehan and others 1989, Crookston and others 1990), the Western Root Disease Model (Frankel 1998), and extensions that represent Douglas-fir beetle and mountain pine beetle. Approximate cost: $56,000; delivery by the end of FY2001.

Enhancement of visualization software to display FFE-FVS model behavior. Approximate cost: $22,000; delivery by the end of FY2000.

Preparation of guidelines for using FFE-FVS-generated visualizations and supporting software in public and educational forums. Approximate cost: $6,000; delivery by the end of FY2000.

Full testing of the effectiveness of using visualization techniques in public forums, including recommendations for changes in approaches: Approximate cost: $34,000; delivery by the end of FY2001.

Modification of FFE-FVS to track the creation of stumps through harvesting and tree mortality, and stump decomposition. Needed to enhance the model's predictions of smoke production. Approximate cost: $12,000; delivery by the end of FY2000.

Provide at least two user training workshops. As FFE-FVS is made available, we need to provide training. During FY99, funding provided from outside the JFSP led to the development of training materials useful for this purpose. The Forest Management Service Center provides routine training for the base FVS. We will augment those sessions with information on the FFE. Approximate cost per 2-day session: $6,000, total $12,000; delivery of 1 during each FY (does not include the cost of participant travel).

Provide routine model maintenance during the development period. Approximate cost: $12,000.

Host a workshop similar to the Seattle Workshop that has a border participation and scope. Approximate cost not counting travel for participants: $23,000; delivery of workshop report by the end of FY2001.

Participation of investigators of this proposal as JFSP-sponsored symposia and workshops requires travel and registration money. Approximate cost: $5,750 per year; $11,500 total.

Technology Transfer

We will provide training and training materials for people who want to use the FFE-FVS. This training will be accomplished in conjunction with the USDA-Forest Services Forest Management Service Center (FMSC), Fort Collins, CO. That group provides training on the base FVS system that is available to all the stakeholders of the JFSP. It is also available to private individuals and state governments. Specific training workshops are deliverables to this proposal.

The Forest Management Service Center has already agreed to provide long-term training, maintenance, and support for FFE-FVS. This support will include a long-term relationship with the original developers of the extension who have agreed to provide technical council and advice to the FMSC as needed to support the model. These arrangements are like those between the FMSC and the developers of the original Prognosis Model for Stand Development and other systems on which FVS is based. For example, principal members of the FMSC have maintained a working relationship with the original Prognosis Model development group for over 20 years. This pattern of long term cooperation will continue with the Fuels and Fire Extension.

Publication of manuals, both via the Internet and traditional printed documents, are part of technology transfer. Provision of these activities are included.

Inclusions of users and other stakeholders throughout the development process is the most important single act in achieving the application of technology. This proposal makes evident our commitment to this idea.

References Cited

Beukema, Sarah J.; 8 others. 1997. An introduction to the fire effects model extension to FVS. In: Teck, Richard; Moeur, Melinda; Adams, Judy, comps. 1997. Proceedings: Forest Vegetation Simulator conference; 1997 February 3-7; Fort Collins, CO. Gen Tech. Rep. INT-GTR-373. Ogden, UT: U.S. Department of Agriculture, forest Service, Intermountain Research Station: 191-195.

Beukema, Sarah; Reinhardt, Elizabeth; Greenough, Julee; Kurz, Werner A.; Crookston, Nicholas; Robinson, Don. 1999. Fire and fuels extension to the forest vegetation simulator: model description. Working draft. Vancouver, BC: ESSA Technologies Ltd. 58 p.

Crookston, Nicholas L. and Albert R. Stage. 1991. User's Guide to the Parallel Processing Extension of the Prognosis Model. Gen. Tech. Rep. INT-281. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 88 p.

Crookston, Nicholas L. 1997. Suppose: An Interface to the Forest Vegetation Simulator. In: Teck, Richard; Moeur, Melinda; Adams, Judy. 1997. Proceeding: Forest Vegetation Simulator conference. 1997 February 3-7, Fort Collins, CO. Gen. Tech. Rep. INT-GTR-373. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station.

Finney, Mark A. 1998. FARSITE: Fire Area Simulator - model development and evaluation. Research Paper RMRS-RP-4. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.

Frankel, Susan J., technical coordinator. 1998. User's guide to the Wester Root Disease Model, version 3.0. Gen. Tech. Rep. PSW-GTR-165. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 164 p.

Keane, Robert E.; Long, Donald G.; Menakis, James P.; Hann, Wendel J.; and Bevins, Collin D. 1996. Simulating Coarse-Scale Vegetation Dynamics Using the Columbia River Basin Succession Model -- CRBSUM. INT-GTR-340 50 p.

Kurz, Werner A.; Beukema, Sarah J. 1999. Decision support needs of JFSP stakeholders and the role of the fire and fuel extension to FVS. Draft report. Vancouver, BC: ESSA Technologies Ltd. 57 p.

Horn, J.E.; Medema, E.L.; Schuster, E.G. 1986. User's guide to CHEAPO II - Economic Analysis of Stand Prognosis Model outputs. General Technical Report INT-211. Ogden, UT: USDA Forest Service, Intermountain Research Station.

McGaughey, Robert J. 1997. Visualizing forest and stand dynamics using the stand visualization system. Proc. 1997 ACSM/ASPRS Annual Convention and Exposition. Bethesda, MD: American Society for Photogrammetry and Remote Sensing. 4:248-257.

Stage, A.R. 1973. Prognosis Model for stand development. Res. Pap. INT-137. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 32 pp.

Teck, Richard; Moeur, Melinda; Adams, Judy, comps. 1997. Proceedings: Forest Vegetation Simulator conference; 1997 February 3-7; Fort Collins, CO. Gen Tech. Rep. INT-GTR-373. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 222 p.

Teck, R.M.; Moeur, M.; Eav, B. 1996. Forecasting ecosystems with the Forest Vegetation Simulator. Journal of Forestry 94(12):7-10.

Wiitala, Marc. 1992. IASELECT: Initial Attack Resource Selector. User's Manual. Aviation & Fire Management, Pacific Northwest Region, USDA Forest Service.

Wykoff, W.R. 1986. Supplement to the User's Guide for the Stand Prognosis Model--Version 5.0. Gen. Tech. Rep. INT-208. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 36 pp.

Wykoff, William. R.; Crookston, Nicholas L.; Stage, Albert R. 1982. User's guide to the Stand Prognosis Model. Gen. Tech. Rep. INT-133. Ogden UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 112 p.