Water scarcity in the southeastern United States has increased in recent
decades due to population growth, land use intensification, and climate
variability. Precipitation is relatively abundant, but declines in
streamflow suggest a need to better manage water yield. Restoration of
low-density, frequent-fire longleaf pine (Pinus palustris Mill.)
woodlands, which once dominated the southeastern Coastal Plain,
represents a possible strategy to increase water yield and mitigate
water scarcity. The Flint River Basin has seen recent conflicts over
water appropriations and lies within the historic range of longleaf
pine. We used the Soil and Water Assessment Tool (SWAT) to evaluate the
potential effect of longleaf pine restoration on streamflow in the
Ichawaynochaway Creek, a major tributary of the Flint River. Parameters
governing plant water use, e.g. leaf area and leaf physiology, were
adjusted to create a longleaf pine land cover. We simulated the
conversion of ~95,000 ha of existing forest to longleaf
pine, an increase from 3% to 35% of landcover in the basin. Modeled
evapotranspiration was lower for longleaf pine compared to other forest
types in the region, and conversion to longleaf pine increased annual
water yield by 17.9 ± 1.6 mm, or 5.2%. Proportional changes in monthly
streamflow were up to 74% higher during low flow periods, when
in-stream habitat is most vulnerable. Restoration of longleaf pine could
be a promising way to mitigate water scarcity in the southeastern U.S.,
and adding flow during extreme droughts may prove vitally important for
conserving imperiled aquatic organisms.
Simulated Longleaf Pine (
Pinus palustris
Mill.) Restoration Increased Streamflow ‐‐ a Case Study in the Lower Flint River Basin