BLM REA COP 2010 LANDFIRE - Fire Regime Condition Class (version 1.0)

Broad-scale alterations of historical fire regimes and vegetation dynamics have occurred in many landscapes in the U.S. through the combined influence of land management practices, fire exclusion, ungulate herbivory, insect and disease outbreaks, climate change, and invasion of non-native plant species. The LANDFIRE Project produces maps of simulated historical fire regimes and vegetation conditions using the LANDSUM landscape succession and disturbance dynamics model. The LANDFIRE Project also produces maps of current vegetation and measurements of current vegetation departure from simulated historical reference conditions. These maps support fire and landscape management planning outlined in the goals of the National Fire Plan, Federal Wildland Fire Management Policy, and the Healthy Forests Restoration Act.Data Summary:The Fire Regime Condition Class (FRCC) data layer categorizes departure between current vegetation conditions and reference vegetation conditions according to the methods outlined in the Interagency Fire Regime Condition Class Guidebook (Hann and others 2004). For the full product description, please refer to Rollins and others 2007, "Developing the LANDFIRE Fire Regime Data Products" available at www.landfire.gov.Scope and Applications:The LANDFIRE Project charter states: "LANDFIRE is a landscape-scale fire, ecosystem, and fuel assessment mapping project designed to generate comprehensive maps of vegetation, fire and fuel characteristics nationally and identify and develop a set of tools to create and distribute data to users." This statement must always frame any discussion about the data products developed by LANDFIRE. Within this context, the summary and reporting of LANDFIRE fire regime data products nationally should include reporting by state and entire bureau/agency ownership. Any characterization or use of the data below that level is the responsibility of the user. Several analysis tools for working with LANDFIRE data products at finer spatial scales have been developed by the National Interagency Fuel Technology Team and are provided as part of the LANDFIRE deliverables (see http://frames.nbii.gov/niftt/).Inherent limitations of LANDFIRE fire regime data products include but are not limited to:1) Establishing break points to simplify and clarify data display. In other words, FRCC is mapped in three distinct categories rather than continuously.2) Data verification is based on field-referenced data that are not nationally consistent in quality or quantity.3) The Landsat imagery used in the data characterization process is several years old (much is from calendar year 2000 and earlier). As a result, recent disturbance and management activities are not represented nor are changes in ecosystems with relatively rapid vegetation succession cycles.4) Edge effects are present due to independent map unit development, relative scale of ecological classification, and limited time available to resolve edge effect issues given the timeframe of the project.Summarization at the national and state levels does not change the relevance of LANDFIRE data that are available to support management decisions at the unit level. The advantages of a nationally consistent data set and repeatable methodology preclude any short comings of the LANDFIRE data products when used at the local level. The information included in this section is derived from an Interagency Fuel Coordination Group memorandum dated April 12, 2007, available at www.landfire.gov.Technical Methods:Ecological Subsections (Cleland and others 2005) are used within LANDFIRE mapping zones to stratify the calculation of vegetation departure. Within each biophysical setting (BpS) in each subsection, we compare the reference percentage of each succession class (SClass) to the current percentage, and the smaller of the two is summed to determine the similarity index for the BpS. This value is then subtracted from 100 to determine the departure index. This departure index is represented using a 0 to 100 percent scale, with 100 representing maximum departure. The departure index is then classified into three condition classes. It is important to note that the LANDFIRE FRCC approach differs from that outlined in the Interagency Fire Regime Condition Class Guidebook (Hann and others 2004) as follows: LANDFIRE FRCC is based on departure of current vegetation conditions from reference vegetation conditions only, whereas the Guidebook approach also includes departure of current fire regimes from those of the reference period.The reference conditions are derived from simulations using the vegetation and disturbance dynamics model LANDSUM (Keane and others 2002; Keane and others 2003; Keane and others 2005; Pratt and others 2006). LANDSUM simulates fire dynamics as a function of vegetation dynamics, topography, and spatial context in addition to variability introduced by dynamic wind direction and speed, frequency of extremely dry years, and landscape-level fire size characteristics. The reference conditions are intended to describe one component of simulated historical fire regimes and vegetation dynamics in the context of the broader historical time period represented by the LANDFIRE Biophysical Settings layer and LANDFIRE Vegetation Dynamics Models. The proportion of the landscape in each SClass in each BpS unit is reported every 20 years during a 10,000-year simulation period. It is important to note that this simulation period represents 10,000 years of stochastic modeling by LANDSUM rather than a depiction of the last 10,000 years of history. These data are prepared for use in the FRCC calculation by first deriving a median value for each SClass across its respective time series and then normalizing the median values to ensure that they sum to 100 percent of the area in the BpS.The current conditions are derived from the LANDFIRE Succession Class data layer; please refer to the product description page at www.landfire.gov for more information. The proportion of the landscape occupied by each SClass in each BpS unit in each subsection is used to represent the current condition of that SClass in the FRCC calculation. The areas currently mapped to agriculture, urban, water, barren, or sparsely vegetated BpS units are not included in the FRCC calculation; thus, FRCC is based entirely on the remaining area of each BpS unit that is occupied by valid SClasses.The fire regime condition classes are defined as follows:Condition Class I: vegetation departure index of 0 to 33Condition Class II: vegetation departure index of 34 to 66Condition Class III: vegetation departure index of 67 to 100Additional data layer values were included to represent Water (111), Snow / Ice (112), Urban (120), Barren (131), Sparsely Vegetated BpS (132), and Agriculture (180).References:Cleland, D.T.; Freeouf, J. A.; Keys, J.E.; Nowacki, G.J.; Carpenter, C.A.; McNab, W.H. 2005. Ecological Subregions: Sections and Subsections for the conterminous United States. (A.M. Sloan, technical editor). Washington, D.C.: USDA Forest Service.Hann, W.; Shlisky, A.; Havlina, D.; Schon, K.; Barrett, S.; DeMeo, T.; Pohl, K.; Menakis, J.; Hamilton, D.; Jones, J.; Levesque, M. 2004. Interagency Fire Regime Condition Class Guidebook. Interagency and The Nature Conservancy Fire Regime Condition Class website. USDA Forest Service, U.S. Department of the Interior, The Nature Conservancy, and Systems for Environmental Management. Available online: www.frcc.gov.Keane, R.E.; Parsons, R.; Hessburg, P. 2002. Estimating historical range and variation of landscape patch dynamics: limitations of the simulation approach. Ecological Modeling 151: 29-49.Keane, R.E.; Cary, G.J.; Parsons, R. 2003. Using simulation to map fire regimes: an evaluation of approaches, strategies, and limitations. International Journal of Wildland Fire 12: 309-322.Keane, R.E.; Holsinger, L.; Pratt, S. 2006. Simulating historical landscape dynamics using the landscape fire succession model LANDSUM version 4.0. Gen. Tech. Rep. RMRS-GTR-171CD. Fort Collins, CO: USDA Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory.Pratt, S.D.; Holsinger, L.; Keane, R.E. 2006. Using simulation modeling to assess historical reference conditions for vegetation and fire regimes for the LANDFIRE Prototype Project. Chapter 10 in: The LANDFIRE Prototype Project: nationally consistent and locally relevant geospatial data for wildland fire management. Rollins, M.G. and Frame, C.K., tech. eds. Gen. Tech Rep. RMRS-GTR-175. Fort Collins, CO: USDA Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory. 277-314.