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definition functions losses alterations Restoration Decisions: (and theory) designtype site reference sites HGM vs. IBI hydrology vegetation soil landscape success criteria floristic quality Abby Rokosch Jessen Book Siobhan Fennessy |
Under the guidance of William J. Mitsch (1998), two experimental one hectare wetlands were dug and established for experimental purposes. Specifically, the project was designed to determine if planted wetland communities were more robust and effective, than "self-designed" communities. To test this, Mitsch planted one of the wetlands with typical wetland emergent vegetation, and left the other barren. While the planted wetland would initially be more successful, Mitsch hypothesized that, over time, the two communities would converge in appearance and in functionality. Essentially, this is just what happened. By the beginning of the fourth year, 58% of the unplanted wetland had accumulated plant coverage, while only 51% of the planted wetland was covered. Furthermore, at the end of three years, species richness had increased from 13 to 65 species at the planted wetland site, and from 0 to 54 species at the unplanted site (Mitsch et al., 1998). This experiment is one of the first large scale ecosystem manipulations of its kind, consequently the data gathered, and the hypotheses suggested, have not yet been validated by other sources. Nevertheless, the potential benefits of using the theory of "self-design" to populate a wetland community must still be considered when beginning a wetland restoration project. |