What is Habitat Suitability Modeling?
Habitat
suitability modeling (HSM) is a statistical method for predicting the
suitability of habitat for a given species. The model identifies the
environmental factors that a species selects for, or avoids, based on the
availability of those factors across a landscape and outputs an index of
suitability based on these factors. Using a geographic information system
(GIS), these index values can be mapped and analyzed to portray areas of
potential habitat for the species. It is important to note that modeling
results do not show the actual occurrence of the species.
How is the Sagebrush Ecosystem Program using HSM?
The State of
Nevada has worked with the U.S. Geological Survey to develop a habitat
suitability model for greater sage-grouse in Nevada. The model uses sage-grouse
telemetry location data and extensive environmental data (vegetation
communities, topographic indices, elevation model, water resources, and human
activity factors) as inputs to predict suitability. The results of the habitat
suitability model were then used to build seasonal habitat suitability index
(HSI) maps, which are used in the Conservation Credit System (CCS), and a
composite HSI map.
The Greater
Sage grouse habitat management category map was developed from habitat
suitability modeling efforts and the resulting HSI maps to represent habitat
areas at the landscape scale and the importance. The Sagebrush Ecosystem
Council formally adopted the December 2015 revision to the Nevada Management
Categories at their December 11, 2015 meeting. This revision included
updated habitat selection modeling by the USGS, updated lek information in the
space use modeling component, the addition of a major road and urban area
mask, and a reduction to the extent of the management categories to the
Biologically Significant Units. In addition, the state has updated
terminology to Priority Habitat Management Areas (PHMA), General Habitat
Management Areas (GHMA), and Other Habitat Management Area (OHMA) to align with
Federal Land Use Plans. This map is used in the CCS, for management of
Greater Sage-grouse in Nevada at the state and federal level, and to support
conservation planning decisions.
Nevada Maps Spatial Data
GIS shapefiles for seasonal/composite habitat suitability and sage-grouse management categories in Nevada and northeastern California have been developed by the USGS and the Nevada Sagebrush Ecosystem Program (Coates et al. 2016). Included is a layer file to symbolize the data following the state's format. Please note there is an August 2014 version and February 2016 version available. The methods to produce both maps are similar; the 2016 maps had several improvements and used the 2014 lek database. Please review the metadata as it describes the methods for developing this layer and use the Coates et al. 2016 citation that is listed in the metadata when referencing the data.
USGS Open File Report
This
peer-reviewed report presents the process for developing spatially explicit
maps describing relative habitat suitability for sage-grouse in Nevada and
northeastern California. Maps depicting habitat suitability indices (HSI)
values were generated based on model-averaged resource selection functions
informed by more than 31,000 independent telemetry locations from more than
1,500 radio-marked sage-grouse across 12 project areas in Nevada and
northeastern California collected during a 15-year period (1998–2013).