First seen in Marin County in the mid-1990s, Sudden Oak Death (SOD) has resulted in the death of millions of oak and tanoak trees in California and Oregon. The cause of SOD is the extremely aggressive fungus-like pathogen Phytophthora ramorum, which can kill an otherwise healthy tree in two years or less.
Oaks and tanoaks play vital roles in Mt. Tam’s forests, providing food and shelter for numerous species, reducing erosion, recharging wetlands and streams, and protecting drinking water. They also store carbon, mitigating the effects of climate change. Their decline is of serious concern.
As large stands of native trees die off, entire ecosystems are changing in undesirable ways. Water, carbon, and nitrogen balances are changing, weeds are proliferating, and the buildup of dry, dead trees and leaves is increasing the risk of catastrophic wildfires.
This project will examine how different forestry practices affect carbon sequestration, water yield, and reforestation potential in SOD-infested areas. For the results to be truly meaningful, the treatment plots must be large, repeated, and spread across a varied landscape. The initial study design proposes the installation of six, five-acre study plots, all within redwood/ tanoak forests. Additional funding would increase the relevance of the study results by expanding the pilot to include mixed hardwood forests and involving more TLC partner agencies.
In the past, we took for granted that our forests would take care of themselves, but in the face of the devastation being caused by SOD, active management is now necessary. Land managers on Mt. Tam—and across the region—need research that will produce actionable knowledge. Support for this project will allow agencies and academics to work together to learn more about the effects of SOD, and how to ensure that the mountain’s oak forests survive into the future.