In wet fall conditions on the forest loam (shaded) at Salerno Lake near Kinmount Ontario this very tall, possible balsam poplar, was found with a perfectly circular, light beige patch as seen in the attached picture. Thanks for any suggestions you may offer.
Thank you for contacting Toronto Master Gardeners.
From the photo, it would appear that this is a campsite. The tree seems to be damaged., not suffering from an infestation or disease in the area of bark in question. The perfectly circular, light beige patch, would indicate that something was attached to the bark, perhaps something with a metal plate. It could have been a sign or a game. Furthermore, there is a crack, which could be anything, running through the damaged part and down below it. Any of the sawdust bits in the circle, might have been made by insects that were exposed when the bark was lifted because of what may have been attached.