It looks like you might have damage from borers. Did you happen to see any ants climbing up the trees? Ants aren’t a problem, but they often indicate that borers are in your tree. Borers are a problem. Borers are a larvea, usually placed by a type of beetle into the trunk of trees and plants. The borers cause damage from the inside out, often creating a hole in which the sap of the tree is released. What kind of plant/tree is it? Your local garden center nursery will have the right chemical to kill the borers.
