Southern Forests and Water

Key Findings from the Southern Forest Futures Project Technical Report

 

Southern forests provide clean drinking water to millions. Photo by U.S. Forest Service.
Southern forests provide clean drinking water to millions. Photo by U.S. Forest Service.

The Southern Forest Futures Project Technical Report is now available online, both in entirety and by chapter. The report forecasts changes in forest conditions and resources based on a variety of scenarios—potential futures—and analyzes what those changes might mean for the future of southern forests. Over the next few months, CompassLive will feature key findings from report chapters to prompt more in-depth reading about the complex issues the South faces in coming years.

The Southern Forest Futures Project (SFFP) started in 2008 as an effort to study and understand the various forces reshaping the forests across the 13 states of the Southeast. Chartered by the U.S. Forest Service Southern Region and Southern Research Station, along with the Southern Group of State Foresters, the project examines a variety of scenarios that reflect different combinations of interconnected factors, including climate change, population growth, land use change, and economic conditions.

Forests in the South provide the cleanest and most stable water supplies for drinking, recreation, power generation, aquatic habitat, and groundwater recharge. Water resources in the South are at risk of degradation from growing population, continued conversion of forests to other land uses and climate change. The SFFP chapter on forests and water evaluates the possible consequences of forest loss from conversion and from changing forest management practices. Chapter authors discuss in depth the implications of climate change, growing demand for water, and land use change on water resources — and the impact of sea-level rise on the coastal plains of the South.

Key findings include:

  • Forest conversion to agriculture or urban use consistently causes increased discharge, peak flow, and velocity of streams. Subregional differences in hydrologic responses to urbanization are substantial.
  • Sediment, water chemistry indices, pathogens, and other substances often become more concentrated after forest conversion. If the conversion is to an urban use, the resulting additional increases in discharge and concentrations will produce even higher loads.
  • Although physiographic characteristics such as slope and soil texture play key roles in hydrologic and sediment responses to land use conversion, land use (rather than physiography) is the primary driver of water chemistry responses.
  • Conversion of forest land to urban uses may decrease the supply of water available for human consumption and increase potential threats to human health.
  • Increases in urbanization by 2060 in the Appalachians, Piedmont, and Coastal Plain will increase imperviousness and further reduce hydrologic stability and water quality indices in the headwaters of several major river basins and in small watersheds along the Atlantic Ocean and Gulf of Mexico.
  • On average, water supply model projections indicate that water stress due to the combined effects of population and land use change will increase in the South by 10 percent by 2050.
  • Water stress will likely increase significantly by 2050 under all four climate change scenarios, largely because higher temperatures will result in more water loss by evapotranspiration and because of decreased precipitation in some areas.
  • Approximately 5,000 miles of southern coastline are highly vulnerable to sea level rise.

 Access the Southern Forest Futures Project Technical Report.

 Access the Summary Report of the Southern Forest Futures Project.

 Access the latest publications by SRS scientists.

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