Competition in the ecosystem- Each tree that's a part of the Hardwood Hammocks can only hold a certain amount of animals and other organisms without being full. To live in certain parts of the Hardwood Hammock, the animals might have to compete with each other. Also, if insects or other animals that get eaten are living in certain parts of the trees, the other animals would have to compete with each other to use that same resource for food.
Commensalism in the ecosystem- The animals living in the Hardwood Hammocks would benefit because they are getting a place to live in and a good community, but the tree isn't being harmed or helped. Animals like birds can make nests and lay eggs in the tree, which doesn't affect the tree.