The Tree Mortality Task Force (TMTF) is comprised of state and federal agencies, local governments,
utilities, and various stakeholders that coordinate emergency protective actions, and monitor conditions
to address large areas of tree mortality resulting from six years of drought and associated bark beetle
activity in California.
Numbers summarized in the new report were generated by the TMTF Mapping and Monitoring Working Group to
provide current estimates of mortality and high hazard zones to support taskforce leadership and
address a variety of information requests from public and private entities. The mortality data is based on
the U.S. Forest Service Aerial Detection Survey (ADS) flown on all forested areas of the State each year.
This document is a revision of the March 2017 publication and uses ADS data from 2010-2017. This
document is current as of April 2018. Values from 2010 through 2017 depict broad mortality trends and
those from 2012 through 2017 are specific to the period described in the Governor’s Proclamation of a
State of Emergency on October 30, 2015 (CA 2015).
The primary focus of this document is the 10 high priority counties identified by the TMTF as suffering
severe mortality. Analogous to the high priority counties, the U.S. Forest Service has identified six
National Forests that are high priorities due to their elevated mortality (see Figure 1). Citations for data
sources used in this report are found in Appendix A. Summaries for other counties can be found in the
USDA Interim Report (USDA 2017b).
See the full report here: TMFacts_and_Figures_April_2018
This link will take you to new Aerial Detection Surveys for each tree mortality in each forest: https://www.fs.usda.gov/detail/r5/forest-grasslandhealth/?cid=fseprd550891