Tree Mortality

Over 100 million trees have died and more continue to die due to many years of drought that have weakened the trees and left millions of acres of forestland highly susceptible to insect attacks. The drought stress is exacerbated in forests with too many trees competing for limited resources, especially water. Tree losses due to drought stress and bark beetle attacks are expected to increase until precipitation levels return to normal or above normal for one to multiple years.

On October 30, 2015 Governor Brown issued an emergency proclamation and established the California Tree Mortality Task Force (TMTF). And on September 1, 2017 Governor Brown issued Executive Order B-42-17 to bolster the state's response to the unprecedented tree die-off.

One goal of the task force was to identify and map areas of tree mortality that pose the greatest potential of harm to people and property. These areas, known as High Hazard Zones, are the areas prioritized for tree removal.

LAUNCH THE VIEWERLaunch the tree mortality viewer

Download HHZ Data

FRAP has created a web-based mapping application through which you can view theTier 1 and Tier 2 High Hazard Zones (HHZ) as well as associated information. Tier 1 HHZ are where mortality and asset to be protected (utilities, roads, recreation sites, etc) directly coincide with mortality identified by the USFS Aerial Detection Survey (ADS) for the years 2012 through 2017. Tier 2 HHZ is based on HUC 12 watersheds (average 24,000 acres) and are intended to focus on ecosystem health and identify watersheds where there is both the greatest amount of ecological asset to be proteced as well as the greatest threat.

In addition to prioritizing areas for tree removal, the Governor's taskCalifornia Tree Mortality Task Force
force established working groups to tackle challenges such as how to utilize the wood once it is removed, and how to restore the forests to a sustainble and healthy ecosytem. You can read more information about the workgroups, including the minutes from their monthly meetings, form the TMTF Working Groups web page.




This Google™ translation feature is provided for informational purposes only.

The California Department of Forestry and Fire Protecton is unable to guarantee the accuracy of this translation and is therefore not liable for any inaccurate information resulting from the translation application tool.

Please consult with a translator for accuracy if you are relying on the translation or are using this site for official business.

If you have any questions please contact us here.

Select a Language Below / Seleccione el Idioma Abajo

Close this box or use the [ X ]