Willows throughout the Escondido Creek watershed have been declining rapidly. We are still not sure why. However, we have decided to open the trails for now based upon discussions with biologists and soils scientists and recently received DNA results from the Eskalen Lab at UC Riverside.
When we first examined the dieback, the prevailing theory was that the trees had all the same signs and symptoms of the Kuroshio Shot Hole Borer (KSHB). Upon speaking to plant biologists and entomologists, in an abundance of caution, we decided to close the trails nearest to the center of the infection.
Yesterday we received DNA results which have deepened the mystery. The DNA sequencing of the first sample came back negative for the Fusarium fungus. Fusarium is the fungus that KSHB transports which helps spread infection. Instead, the pathogen detected was a fungus called Phaeoacremonium.
In communications with Dr. Eskalen, he was interested as to why our willows trees have died so quickly from this particular fungus, which is known to slowly kill trees. He wondered if something else may additionally be affecting these willows. In that regard, he asked for more pictures and samples which we provided today for additional testing. We are also investigating treatment options that may help the willows fight off the infection.
For now, we have opened the trails but remind visitors and Elfin Forest residents, please: stay on trail, keep all dogs on leash, and no matter what, DO NOT MOVE FIREWOOD!
We will adjust our recommendation, if needed, as new information is available. Thank you for your patience as we learn together.
Contact firstname.lastname@example.org with any questions.