Restoration Decisions: (and
HGM vs. IBI
State of the Science
Jessen Book Siobhan Fennessy
Types of Alterations to Wetlands (World Wildlife Fund and The Conservation Foundation, 1988 in National
Research Council, 1992).
- Grazing--consumption and compaction of vegetation by either domestic or wild animals.
- Disrupting natural populations
- Changing nutrient levels--increasing or decreasing levels of nutrients within the local water or soil system;
forcing changes in wetland plant community.
- Introducting toxics--adding toxic compounds to a wetland either intentionally (e.g. herbicide treatment to
reduce vegetation) or unintentionally, adversely affecting wetland plants and animals.
- Filling--adding any material to change the bottom level of a wetland or to replace the wetland with dry land.
- Draining--removing the water from a wetland by ditching, tiling, pumping, and so on
- Excavating--dredging and removing soil and vegetation from a wetland
- Diverting water away--preventing the flow of water into a wetland by removing water upstream, lowering lake
levels, or lowering ground water tables.
- Clearing--removing vegetation by burning, digging, application of herbicides, scraping, mowing, or otherwise
- Flooding--raising water levels, either behind dams or by pumping or otherwise channeling water into a wetland.
- Diverting or withholding sediment--trapping sediment through
construction of dams, channelization, or other types of projects,
thereby inhibiting the regeneration of wetlands in natural areas
of deposition such as deltas.
- Shading--placing pile-supported platforms or bridges over wetlands, causing vegetation to die.
- Conducting activities in adjacent areas--disrupting the interactions
between wetlands and adjacent land areas, or incidentally impacting
wetlands through activities at adjoining sites.