Oak Detective

We've been losing many of our oaks at the Arboretum.  We've also been looking for a reason for their death.  Sure, there are the customary oak problems, Armillaria and Phytophthora on some, Hypoxylon and ambrosia beetles on others, and every other combination you might be able to think of.  We've had all the experts look at declining oaks on the property, but so far, no pattern has been established to explain what is going on. 

I happened to be out looking at something else with Kevin, and he directed me to the north side of the Azalea Collections where I met a chain saw wielding expert from the Forest Service.  He had cut down a small chestnut oak, Quercus prinus, and had collected all kinds of samples.  It looked a bit like a crime scene with evidence collection taking place. 

Chris Carley, on the right below was there and has been a key player in bringing forestry types and plant pathologists to the Arboretum to collect data that might point to a cause or causes for the loss of our oaks.  He's also been monitoring our property carefully for emerald ash borer and Asian longhorned beetle.  I'm happy to report that neither have been found so far, but Chris's work as part of the American Public Gardens Association's Sentinel Plant Network is a key part of keeping ahead of new pest and disease problems.  

Even though we haven't found a pattern to the oak deaths, careful observation and data collection will help us understand what is going on.  It might be a natural cycle of death that is part of the progression toward climax forest, or there may be underlying causes that we can diminish to help our oaks survive.