LANDFIRE.AK_140VDEP

Metadata Updated: November 12, 2020

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 Program produces maps of simulated historical fire regimes and vegetation conditions using the LANDSUM landscape succession and disturbance dynamics model. The LANDFIRE Program also produces maps of current vegetation and measurements of current vegetation departure from simulated historical reference conditions.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 Vegetation Departure (VDEP) 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). Technical Methods: Summary units for the departure computation were defined as a BioPhysical Setting (BpS) with identical reference condition values regardless of map zone. This is a change from previous versions of LANDFIRE. For example, speculate that a particular BpS is present in map zone 1, 2, 4, 5, 6 and 8. The reference conditions for this BpS are identical in map zones 1, 2, 4, 5 and 8 so those map zones become a summary unit for the departure computation (VDEP) in LF2014. Since reference conditions are unique for this BpS in map zone 6, it is a separate summary unit for calculating departure (VDEP) in LF2014. Within each biophysical setting in each summary unit, 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 value. Departure value is between 0 100, with 100 representing maximum departure. The LANDFIRE VDEP approach differs from that outlined in the Interagency Fire Regime Condition Class Guidebook (Hann and others 2004) as follows: LANDFIRE VDEP is based on departure of current vegetation conditions from reference vegetation conditions only, whereas the Guidebook approach includes departure of current fire regimes from those of the reference period. The reference conditions are derived from quantitative vegetation and disturbance dynamics models developed in VDDT/ST-Sim. The current conditions are derived from the corresponding version of the LANDFIRE Succession Class data layer; please refer to the product description page at landfire.gov for more information. The proportion of the landscape occupied by each SClass in each BpS unit in each summary unit is used to represent the current condition of that SClass in the VDEP calculation. The areas currently mapped to agriculture, urban, water, barren, or sparsely vegetated BpS units are not included in the VDEP calculation; thus, VDEP is based entirely on the remaining area of each BpS unit that is occupied by valid SClasses. Additional data layer values were included to represent Water (111), Snow / Ice (112), Urban (120), Barren (131), Sparsely Vegetated BpS (132), and Agriculture (180).

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License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Date February 1, 2007
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) December 9, 2016 (publication)
Frequency Of Update continual

Metadata Source

Harvested from DOI Open Data

Additional Metadata

Resource Type Dataset
Metadata Date February 1, 2007
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) December 9, 2016 (publication)
Responsible Party Wildland Fire Science, Earth Resources Observation and Science Center, U.S. Geological Survey (Point of Contact)
Contact Email
Guid
Access Constraints Use Constraints: This product is reproduced from geospatial information prepared by the U.S. Department of Agriculture, Forest Service and USGS EROS. By removing the contents of this package or taking receipt of these files via electronic file transfer methods, you understand that the data stored on this media is in draft condition. Represented features may not be in an accurate geographic location. The Forest Service and USGS EROS make no expressed or implied warranty, including warranty of merchantability and fitness, with respect to the character, function, or capabilities of the data or their appropriateness for any user's purposes. The Forest Service and USGS EROS reserve the right to correct, update, modify, or replace this geospatial information without notification., Access Constraints: None
Bbox East Long -138.75803269007818
Bbox North Lat 71.14926911648406
Bbox South Lat 50.824773478534226
Bbox West Long -179.8299135763675
Coupled Resource
Frequency Of Update continual
Licence This product is reproduced from geospatial information prepared by the U.S. Department of Agriculture, Forest Service and USGS EROS. By removing the contents of this package or taking receipt of these files via electronic file transfer methods, you understand that the data stored on this media is in draft condition. Represented features may not be in an accurate geographic location. The Forest Service and USGS EROS make no expressed or implied warranty, including warranty of merchantability and fitness, with respect to the character, function, or capabilities of the data or their appropriateness for any user's purposes. The Forest Service and USGS EROS reserve the right to correct, update, modify, or replace this geospatial information without notification.
Metadata Language
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True

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