SAN DIEGO -- In a unanimous vote on Wednesday, the San Diego County Board of Supervisors established a program to remove dead, dying and diseased trees in an effort to reduce the risk of wildfires.

The Fire Safety and Fuels Reduction Program will be funded with $39.9 million in federal grants accepted by supervisors last month to remove dead trees in the county's unincorporated areas over the next four years. To augment the U.S. Department of Agriculture grants, the county will pay $5 million.

"Two-thirds of the county did not burn in the October fires, and many communities still face extreme fire danger," Supervisor Dianne Jacob said. "Today's action will help to significantly ramp up the removal of dead and diseased trees."

The program will include assessment and prioritization of which communities are most at risk. Dead trees and vegetation will be removed and an environmental review will be conducted. The program will also provide for community outreach and education. Workers will begin removing trees immediately.

According to a county report, as many as 80 percent of trees have been killed off by prolonged drought and beetle infestations in some unincorporated county areas.

Last month, Chuck Bell, a state conservationist, declared an "extreme emergency situation" because of the dead trees and an early fire season. That declaration allows the Natural Resources Conservation Service to use federal funds to cover eligible costs associated with the removal of dead trees in San Diego, San Bernardino and Riverside counties, without local governments having to match the grants.

"Considering the critical nature of the impending fire season, it is necessary to immediately reduce the risk of wildfires through hazard mitigation, prevention and fuel reduction activities and open evacuation corridors," a county report states.

The county is home to 72 communities that are considered at risk, according to the report, which says residents living where wild land and urban areas meet are most vulnerable.

The U.S. Forest Service estimates that 62,000 acres of insect-killed trees are scattered throughout Palomar Mountain, Harrison Park, Cuyamaca, Laguna Mountain, Descanso, Pine Valley and areas near Warner Springs.