Soft bark on an aspen
I have two aspen trees located on the south side of my property with a lot of sun exposure. They are both experiencing a soft tree trunk/bark. I cut off all of the death branches and trimmed it back a little. Well, the leaves on the other branches are now turning brown/yellow brown, I suspect it is also affected by what I believe to be some sort of fungus. What can I do to salvage these beautiful tree?
Adams County Colorado
From the pictures and your description this sounds like what you are seeing could indeed be caused by a fungal pathogen. While the specific fungus could be one of several species my best guess would be that it is Cytospora. Unfortunately, there is no treatment for this issue. We have had an uptick in this and related disease issues this year due to all the moisture we have had. Though sadly, aspen are not a particularly long lived tree along the Front Range anyways.
You can find more information here: https://extension.colostate.edu/topic-areas/yard-garden/cytospora-canker-2-937/
I hope this helps, please let me know if you have further questions.