Answer: Based on your description I am not certain I am picturing the situation accurately. However, if there is dead wood on a tree it should be removed. The new growth coming from the bottom sounds like it is healthy, so it can be left intact. Usually when this occurs the younger gree is growing on the root of the original tree so it grows very quickly. Take care not to damage it when removing dead wood on the older tree. If this is a large tree and would require a ladder to remove the dead portion, I would strongly suggest you work with a professionally trained and certified arborist to either prune it or remove it safely. I'm sorry about your tree.
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