Forest ThreatNet

Changes in global bioenergy consumption have important implications for managing forest plantations as an alternative energy source in the southeastern United States. Forest Service and university researchers partnered to examine how resulting pine plantation management strategies affect water yield from planted watersheds. The research suggests that landowners have agency over forest water yield, and that local water supply shortages might be mitigated by changing forest management strategies in the context of a changing climate.

Bioenergy development policy has had a growing impact on how forests and plantations are managed in the Southeastern United States. But the implications of these changes for forested watersheds and the water they supply have not been well understood. To address this knowledge gap, a collaboration between Forest Service and University scientists set out to quantify water yield impacts from pine plantation management strategies to support bioenergy development policy. The group assessed effects of thinning, clear-cutting, and shortened harvest rotations on water yield across a 55-year time horizon at both pine plantation (i.e., local site) and broader watershed scales in northern Florida, southern Georgia, and southern Alabama. The study showed that tree thinning resulted in the smallest increase in water yield, while clear-cutting imposed the greatest increase for the site scale and up to 25% at the watershed scale. Short-rotation management caused site-level water yield increases ranging from 10% to 50%. Overall, greater water yield effects were seen at the site level, rather than across whole watersheds. These findings suggest that landowners could manipulate their plantations to mitigate local water supply shortages by changing forestry biomass management strategies. The opportunity to supplement local water availability is especially valuable within the context of a changing climate.