Beginning of the End

I'm told that fungus on the trunk of a tree is a sign that it's decaying inside.

Whether this particular bracket is cause or symptom I don't know, but I'm going to be cheeky and suggest that decay and dereliction often coincide (and mushrooms are given as examples). Think I'll do some more reading to gain a clue about the cause or effect puzzle. 

Thanks for hosting derelict,  Marlieske.