Relative Abundance of Shrub Vegetation Type
The indicator measures the proportion of land cover dominated by shrub vegetation in the Tahoe Region. Shrub vegetation represents an early successional stage of forest vegetation. The relative proportion of shrub type is important as it provides habitat for a wide diversity of wildlife species and complements vegetation diversity in the Region. The primary factors responsible for shrub vegetation are light exposure, soil type and moisture content, and extent and frequency of wildfire and other natural disturbances. TRPA has adopted policies and ordinances designed to promote a diversity of native vegetation communities in the Region. Forest fuels reduction projects affiliated with the Environmental Improvement Program tend to target the removal of understory shrubs to meet fuels reduction objectives and to prevent an overabundance of shrub-dominated vegetation type.
Status
Estimated percent of land area dominated by “shrub” vegetation in the Lake Tahoe Region relative to TRPA adopted numeric target (25%). Recent changes in the percent cover of Shrub can be attributed to the 2007 Angora fire, as well as different interpretations of the baseline amount of “undisturbed” vegetation and changing mapping techniques/resolution, not necessarily actual changes in vegetation type. Sources: (USDA 2009)
Evaluation Map
Vegetation Distribution in the Tahoe Region - 2010 Ecobject.
2019 Evaluation
- Status
- Considerably Better Than Target
- Trend
- Little or No Change
- Confidence
- Low
Applicable Standard
VP6) Relative Abundance - Of the total amount of undisturbed vegetation in the Tahoe Basin: Maintain no more than 25% dominant shrub association vegetation.
Key Points
- Maintaining no more than 25 percent shrub vegetation type is valued as wildlife species habitat when interspersed with other vegetation types, such as forests and meadows.
- Shrub plant community acreage is 14 percent of total undisturbed acreage in the Region, considerably better than target.
- Changes in the percent cover of shrub vegetation type from 2007 to 2011 are a result of the 2007 Angora fire as well as different interpretations of the baseline amount of “undisturbed” vegetation and changing mapping techniques/resolution, not necessarily actual changes in vegetation type.
Delivering and Measuring Success
EIP Action Priorities
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Reduce Hazardous Fuels
The Tahoe Fire and Fuels Team is working to thin overstocked forests to reduce hazardous fuels and improve ecosystem resilience. As of 2020 partners have completed 87,000 acres of forest treatments.