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National Fire Plan Success Story

Research Improves Understanding of Critical Forest Health Problem
Point Reyes National Seashore, California
National Fire Plan - Accountability
2011

Fire ecologist Alison Forrestel.
Fire ecologist Alison Forrestel researching Sudden Oak Death in redwood forest (NPS).

An area of collapsed trees.
Collapsing trees increase down woody fuels in forests infected by Sudden Oak Death (NPS).

Two persons planting acorns in a green house.
Acorns being planted for tanoak resistance study (USFS).

Research partnerships are proving essential for Point Reyes National Seashore to understand better the effects of Sudden Oak Death in different ecosystems. This includes monitoring changes in fuels and forest structure as well as studying tanoak resistance with partners from the University of California Berkeley and the USDA Pacific Southwest Research Station. In 2007, Sudden Oak Death was estimated to be affecting approximately 64% of redwood forests, 45% of coast live oak forests and 24% of Douglas-fir forests in the park. Tanoak, the tree most heavily impacted by this disease is found in all of these forest types. Increasing tanoak mortality is almost certain to cause changes in species composition and fuel loads. Tanoak acorns are an important part of the food chain which if removed from the ecosystem could have many impacts on wildlife including species already threatened such as the Northern Spotted Owl. Managers cannot effectively respond to this epidemic without more research and monitoring.

Long Term Monitoring

The first phase of a long term monitoring study has shown that Sudden Oak Death at Point Reyes National Seashore progressed more quickly in Douglas-fir forests than in redwood forests between 2007 and 2009. However, the Douglas-fir forests had more diversity of hardwoods suggesting the ecological effects may not be as severe. Tree regeneration in forest openings created by Sudden Oak Death is dominated by resprouting tanoak, bay and redwood. So far, there is no evidence of invasive plants moving into these areas. Fuel loads were higher in diseased areas in both forest types. The long term monitoring plots will be read again in 2011 by the fire effects crew for the San Francisco Bay Area National Parks.

Redwood Forest Fuels

The potential for greater impacts in the redwood forest led to a fuels study on Marin Municipal Water District lands adjacent to Point Reyes National Seashore. This work indicated clear patterns of increased fine and large fuel loads associated with increased Sudden Oak Death (SOD) as well as potential for greater fire intensity and more passive crown fire than in healthy forests. Increased fire intensity in SOD infected redwood forest was observed by firefighters during the 2008 Basin Fire near Big Sur. Muir Woods National Monument and Redwood National Park also have significant redwood forest resources which are threatened by Sudden Oak Death.

Tanoak Resistance

In September 2008, San Francisco Bay Area National Parks staff collected tanoak acorns from Point Reyes for a tanoak resistance project. Approximately 70 acorns were collected from each of 20 tanoaks that were still thriving in areas where other tanoaks have died from the disease. This is part of a large study which seeks to learn whether some tanoaks are resistant to the disease. If so, they could be used to propagate disease resistant trees for restoration. Acorns from sites ranging from central California to southern Oregon are being germinated and grown into young trees which are then intentionally infected with the disease hoping to find survivors.

Contact: Jennifer Chapman, Fire Communication and Education Specialist, (415) 464-5133