Guidance on Creating Treatments and Disturbances with Edit Rules

Introduction

IFTDSS Landscapes are supplied by LANDFIRE. Regardless of what tool you use - IFTDSS or a GIS - the basics of editing fuels for treatment planning are really about understanding the LANDFIRE fuel data and how changes to that fuel data impact fire behavior.

About Making Your Own Landscape Edits

It is important to note that landscape features are independent of each other. For example, editing one feature such as Fuel Model, will not change the other features such as canopy height cover, etc. Each of these features must be edited separately.

The most important part of editing fuel models and canopy characteristics is understanding that you are really making edits to show the resulting fire behavior, not necessarily what the vegetation ‘looks’ like. The resultant fire behavior has to make sense to you. If it does not, then the edits are not appropriate for your situation and need to be adjusted. Run the fire behavior before and after editing and evaluate whether the resulting fire behavior is what you would expect. This may take a number of iterations, some trial and error, and probably some discussion with your silviculturist or another colleague that is familiar with your fuel types and the effects of treatments.

Editing landscape data is a bit of an art and a lot of ‘gut feeling’. Currently, there are no courses or training materials that teach the details of landscape editing. The best resources are often colleagues that are familiar with your fuel types and the effects of treatments. However, the resources below may also be helpful.

Resources

Fuel Model Resources

• Scott and Burgan 40 Fuel Models Guide

• Original 13 Fuel Models Guide

• Downloadable spreadsheet to compare fuel models

Canopy Features

• Canopy Fuel Characteristics of Conifer Forests (8 pgs)

• Stereo Photo Guide for Estimating Canopy Fuel Characteristics in Conifer Stands

Evaluating Edits

• NWCG Fire Behavior Field Reference Guide , section on Landscape Acquisition, Critique, and Editing : Basic information on representing disturbance.

• LANDFIRE Fuels Data Acquisition, Critique, Modification, Maintenance, and Model Calibration : Editing resources with some examples.

• Modifying LANDFIRE Geospatial Data for Local Applications

• LANDFIRE Additional Documentation on Editing Rules

About Using Landscape Edit Rules

The same need for evaluating fire behavior when using your own rules applies to using Default Edit rules. The Default Edit rules can save time by allowing you to make the changes you think will occur with a particular treatment. Default Edit rules implement landscape edits to represent a specific treatment, from there, you can evaluate what the fire behavior looks like and decide if you agree or need re-evaluate.

It is a best practice to evaluate your landscape changes and fire behavior after applying a Default Edit rule, to ensure that the landscape features and fire behavior are what you would expect.

Currently, Default Rules are not available for LANDFIRE landscape versions 2016 and later. The team is working on adding updated rules for later landscapes.

Reproducing Old Default Edit Rules with User Created Rules

Why Replicating With User Created Rules Can Be a Challenge

It is difficult to apply the User Created Edit Rules to same effect as the Default Edit Rules because the Default rules are based on other settings and characteristics in the LANDFIRE data that are more complex than what the User Created Edit Rules offer. Below is some additional info and a couple ways to approaching that.

The IFTDSS Default Edit Rules are driven by LANDFIRE Look-up Rules, based on LANDFIRE veg type, cover, height, and the lcp features. While the description in IFTDSS generally summarizes what the rule does, there’s bound to be some variation or other details based on modeled tree growth after the disturbance.

Ways to Approximate Default Rules

To capture as many factors as possible it may be worth consulting your silviculturist and have them do paired FVS runs for a like stand. Then use change factors like increasing the Canopy Base Height by x%. Then those outputs could be referred to as you develop your User Created Edit Rules, making rule sets based on the changes due to treatment. For example, thinning trees up to 3” diameter at breast height (DBH) in FVS (Forest Vegetation Simulator) may reduce canopy cover by 5% but only in areas where it’s >60% to start. Translating that to a User Created Edit Rule, you could make a rule that multiplies Canopy Cover by 0.95 where it is >60%.

It may also be worth noting that removing small trees might not have a big change on any canopy characteristics, depending on the current conditions. Since the Canopy Cover, Canopy Base Height, Canopy Height and Canopy Bulk Density is heavily weighted to the larger trees, though that depends on the vegetation/stand.

If you don’t have FVS experience, or access to someone who does, an alternative would be one of trial and error within IFTDSS. In that case you could change specific stand characteristics with the User Created Edit rules, run behavior on the subsequent landscapes, calibrate your landscape edits based on that. Another option would be focusing on the Fire Behavior Fuel Models, making changing their, and analyzing the fire behavior that results. This last step is important in any case to ensure the fire behavior being modeled looks accurate given the weather and fuel moistures you’re working with.

Cross walking something like DBH to fuel models is tricky and you may end up needing to use a shrub model if you are trying to model fire behavior in thicker stands with a lot of understory.