re: My lawn from hell. How do I fix this?

Looks like my yard.
My neighborhood is in the Honey Island Swamp, and the swamp is reclaiming the ground. The back 3 ft. of my yard along my fence is just a carpet of green moss now - though it looks sorta like a putting green. And in the past year I must have found two dozen different kinds of mushrooms in my yard. It's kind of cool, because I'm seeing some colorful mushrooms that I've never seen before in my life. And the few low spots that hold water when it rains now have "pond" plants.