Effect of forest management practices on southern forested wetland productivity

Abstract

Abstract:In the interest of increasing productivity of forested wetlands for timber production and/or wildlife value, management schemes that deal mainly with water-level control have been developed. The three forest types in the southeastern U.S. most commonly affected are cypress/tupelo forests, bottomland hardwood forests, and wet pine sites (including pocosins). In forested wetlands, hydrology is the most important factor influencing productivity. In bottomland and cypress/tupelo forests, water-level control can have mixed results. Alterations in natural hydrologic patterns leading to increased flooding or drainage can cause decreased growth rates or even death of the forest. Bottomland hardwoods respond favorably in the short term to water-level management, but the long-term response is currently under study, in wet pine sites, timber volume can be increased significantly by water-level management, but the impact upon other ecological functions is less understood. It is difficult to adequately describe productivity relations in wetland forests because of the great diversity in habitat types and the lack of data on how structure and function might be affected by forestry operations. There is a definite need for more long-term, regional studies involving multidisciplinary efforts.

Responses of vegetation to a rise in water level at Kerkini Reservoir (1982–1991), a Ramsar site in northern Greece

“…Hydrology is the most important factor controlling the ecosystem dynamics in forested wetlands (Hall and Smith 1955, Gill, 1970, Harms and others 1980, Brinson and others 1981, Conner and Day 1988, Day and others 1988, Day and Megonigal 1993, Conner 1994. Flooding is a stress for trees, which shows itself first by changes in soil oxygenation (soils become anaerobic) and soil chemistry (Ponnamperuna, 1970(Ponnamperuna, , 1984.…”

Litterfall in the hardwood forest of a minor alluvial-floodplain

“…These reviews included few, if any, wetland forests from the Southeastern USA. Mean total litterfall in the Iatt Creek study was 83% above the mean (446 g m À2 year À1 , range 63-724 g m À2 year À1 , n = 34) for the natural wetland-forests summarized by Conner (Conner et al, 1990;Conner, 1994); however, these forests, although in the Southeastern USA, included primarily deep-water swamps and major alluvial-floodplains. The Iatt Creek study was 43% above mean total litterfall (570 g m À2 year À1 , range 422-720 g m À2 year À1 , n = 13) for a group of wetland forests that included less hydric sites (Brinson et al, 1980;Brown and Peterson, 1983;Shure and Gottschalk, 1985;Conner et al, 1993;Jones et al, 1996;Burke et al, 1999) and 49% above the mean (548 g m À2 year À1 , range 336-902 g m À2 year À1 , n = 21) for a cross-section of Southeastern USA hardwood and coniferous forests compiled by Clawson et al (2001).…”

“…Summaries by Shure and Gottschalk (1985), Conner et al (1990), Conner and Day (1992), Conner (1994), and Conner and Buford (1998) cite litterfall transfers from 47 forested wetlands as reported in 25 articles. Studies by Megonigal et al (1997), Burke et al (1999), and Busbee et al (2003) report annual litterfall from an additional 24 wetland stands.…”

“…Studies by Megonigal et al (1997), Burke et al (1999), and Busbee et al (2003) report annual litterfall from an additional 24 wetland stands. Though this array of studies has addressed a variety of questions, most studies have been of deep-water wetlands (Conner and Day, 1992;Conner, 1994) or major alluvial-floodplains. Although a significant and dramatic segment of these wetland forests, they are not the only wetland forests.…”

Fine Root Productivity and Dynamics on a Forested Floodplain in South Carolina.

“…Most commonly, productivity is estimated using aboveground parameters such as litterfall and stemwood production (B&son et al, 1980;Conner and Day, 1992;Conner et al, 1993;Conner, 1994;Megonigal et al, 1997). Many investigators have acknowledged, however, that failure to include belowground data will seriously underestimate forest ecosystem productivity (Vogt et al, 1986a;Day and Megonigal, 1993).…”