Field Note No. 21
Date: 15 October 2026
Status: Scanned, and good news
A fungus at the base of Oak 41 prompted a closer look.
Sensors are fixed around the trunk. At each point, the wood is tapped five times, and the sound travels between the sensors.
The Picus sonic tomograph turns those readings into a picture of the inside of the trunk. The scan shows no sign of a cavity.
The scan has shown how far the fungus has reached, and it’s a good story to tell. Trees can stand for years with it, and this one has been looked at closely.
