Originally posted by KC0PET Yes, that is why ash trees and some other varieties can rot from the middle out and show almost no sign of problem until they are just about gone. I have fortunately removed a couple like that near our house and it was disconcerting how little was left of the inner trunk.
If we think about the "life" as animal den space as part of the life of a tree, then all of the trees that lose their cores have more life to them. Apple trees, if let untrimmed, develop a lot of hollow branches when in advanced age. There was a time when those branches were favorites for bluebird nesting sites. When orchards began trimming off old limbs, that nesting habitat was gone. Even when a tree falls onto the forest floor, if all of the root connections haven't broken, part of the tree might still leaf out for a few more years, and then there are species like the ashes you mentioned that often send up new sprouts from stumps, especially when they are cut down. I even like to think of the fallen dead tree as part of the tree's stages of life--when the fallen tree is hollow it increases animal den sites, squirrels will cross the forest floor more quickly (or escape predators more easily) by bounding along fallen trunks. Even when the fallen trunk is turning into something the consistency of peat moss, if you pick it up, look at it, smell it, you can tell it is full of life and full of nutrition for the next generations of trees and other forest plants.