It’s a widely known fact these days that oak barrels are rare and being sold at a premium. It’s an issue affecting winemakers, brewers and distillers alike. In a previous post, we cited Sudden Oak Death as a partial cause for the nation’s continued shortage of oak barrels. But what exactly is Sudden Oak Death and how long has it been plaguing our forests?
Sudden Oak Death is a tree disease caused by the plant pathogen Phytophthora ramorum. The pathogen has been killing millions of tanoak trees as well as several oak tree species since the mid-1990s, but the pathogen’s origin is still unknown. Oak species affected include coast live oak, California black oak, Shreve oak and canyon live oak.
In 2004 a few large West Coast nurseries inadvertently shipped over a million infected plants throughout the United States and suddenly P. ramorum was detected in 176 nurseries in 21 states. This is when the U.S. nursery industry truly felt the impact of the disease.
P. ramorum thrives in cool, wet climates. In California, nurseries within the fog belt provide a satisfactory habitat for the pathogen to grow and spread.
The name Sudden Oak Death might seem extreme, but it is mostly accurate. Trees are infected through the trunk or sometimes the leaves for tanoaks. Symptoms include large ‘bleeding’ cankers in the trees trunks and wilting new shoots or foliage discoloration. Some trees die immediately, but appear to be alive for a while longer as it takes some time for their leaves and branches to brown. In some cases, leaf death doesn’t occur for a year after the initial infection. Not all infected plants die, to some non-oak species the infection is non-lethal and every tree responds differently. However, ambrosia and bark beetles are naturally drawn to infected trees and their infestation can be the kiss of death for a tree that may otherwise survive the disease.
Sudden Tree Death has been found abroad in Germany, Wales, Ireland and England and is still a slight mystery to researchers. Disease progression is still unknown on a variety of species, but one thing is for certain: the ecological threat is severe. Dying trees affect the species composition and, therefore, the ecosystem of forests. A shift in the ecosystem can lead to loss of food sources for some wildlife, a change in forest fire frequency or intensity and a decreased water supply and quality due to an increase in exposed soil surfaces.
While the ecological impact is still being monitored, the economic impact is clear, if only for coopers and barrel-users. With fewer oak trees, there are fewer new oak barrels being produced each year. The disease is affecting a number of oak-dependent industries, but winemakers and distillers are doing what they can to proceed with business. Stainless steel barrels have emerged as a powerful and reliable substitute and winemakers are growing more innovative in their oak flavoring techniques.
Our forests need a cure and our ecosystem needs these suffering species to survive, but winemakers, it seems, adapt and prevail.