Approximately half of U.S. wetlands present in colonial times have been lost, primarily due to agriculture. The South had approximately 35 million acres of forested wetland remaining by 1996, 91 percent of which were riverine wetland.
Rates of loss—change from wetland to nonwetland—were greatest from the 1950s to the 1970s. Since then the rates have slowed, but losses are still occurring due to agriculture, urban and rural development, and silviculture.
According to the National Wetland Inventory (NWI), 3.5 million acres of southern forested wetland underwent changes between 1986 and 1997. Ninety percent of the changes were conversions to another wetland or aquatic habitat type. Of these conversions 95 percent were to scrub-shrub or emergent wetlands. During this same time period approximately 119,000 acres of forested wetland went into urban and rural development, 112,000 acres were converted to agriculture, and 102,000 acres underwent intensive silviculture. While NWI attributes causes of losses, they do not attribute causes of conversion.
Effects of harvesting are short lived, and harvested riverine stands will return to pretreatment species composition; however, additional long-term research is needed to compare composition and ecological function of harvested and nonharvested stands.
As of 1997, Georgia, Florida, and Louisiana have the greatest amount of forested wetland in the South, followed, in descending order, by Mississippi, South Carolina, North Carolina, Arkansas, Texas, Alabama, Virginia, Tennessee, and Kentucky.
Restoration has been attempted primarily in riverine wetlands in the Lower Mississippi Valley, but success in restoring wetland acreage and function has been limited. Restoration of other forested wetlands, like mineral-soil pine flats, would have to include the reintroduction of fire.
Offsetting losses of wetland functions through the Clean Water Act, section 404 permitting process has not been well documented but appears to have had limited success.
