Forests at Risk: Swiss Needle Cast Epidemic in Douglas-Fir Trees Unprecedented, Still Getting Worse- ScienceDaily – (Apr. 12, 2010)

Link: http://www.sciencedaily.com/releases/2010/04/100405152557.htm

Source: Science Daily / University of Toronto

Coastal Pacific Northwest Forest Grove - photo credit Jim Mau c 2010

Researchers at the College of Forestry at Oregon State University (OSU), in a paper published in the professional journal Forest Ecology and Management, state that Swiss needle cast is epidemic in Douglas-fir forests of the coastal Pacific Northwest, is continuing to intensify and appears to be unprecedented over at least the past 100 years.

Swiss needle cast is a native fungal disease specific to Douglas-fir first described in Europe. Rarely does Swiss needle cast kill trees but it does cause discoloration, loss of needles and growth reduction. Swiss needle cast is common in the Pacific Northwest wherever Douglas-fir grows. Since it began to develop in1984, a perfect storm of conditions that favor this fungus has caused a major epidemic that continues to grow today.

The OSU study concluded that warmer conditions are associated with significantly reduced growth in diseased trees, which may reflect earlier fruiting of the fungus

The researchers say this is the result of the planting a monocultures of Douglas-fir for decades in replacement of coastal forests, which previously had trees of varying ages and different species.

Weather is known to be a driver in the epidemiology and spread of this disease and while it can not be said yet whether climate change is part of what’s causing these problems, certainly warmer conditions, milder winters and earlier springs would be consistent with the spread of this fungus.

Swiss needle cast has been shown to be associated with climate, especially long-term warming trends during the late winter and early spring.

MLA – Oregon State University. “Forests at Risk: Swiss Needle Cast Epidemic in Douglas-Fir Trees Unprecedented, Still Getting Worse.” ScienceDaily 12 April 2010. 12 April 2010 <http://www.sciencedaily.com/releases/2010/04/100405152557.htm>.

Journal Reference:

1. Black et al. Impacts of Swiss needle cast on overstory Douglas-fir forests of the western Oregon Coast Range. Forest Ecology and Management, 2010; 259 (8): 1673 DOI: 10.1016/j.foreco.2010.01.047

Forest Ecology and Management : http://dx.doi.org/10.1016/j.foreco.2010.01.047