The progression of eutrophication events for ponds and lakes can eventually create detritus layers that produces successively shallower depths of surface waters. Eventually the water body can be reduced to a marsh or bog, whose plant community is transformed from an aquatic environment to a recognisable terrestrial ecosystem. While this system may first emerge as a plant succession of marsh grasses and related aquatic forbs, the community may evolve to be more of a bog or fen, and finally a vernal pool or meadow. This progression can clearly spawn radical changes in the entire ecosystem, which began as an aquatic habitat, and has been transformed into a fully terrestrial community, albeit inhabited by a number of mesic plants and water oriented animals such as amphibians.