Grassy oak savannas and sunny pine woodlands were once a common sight across the eastern U.S. These open forests have fewer large trees in the overstory and a bounty of native grasses and flowering plants in the understory. Frequent fire limited tree regrowth and created the open canopy.
USDA Forest Service scientist Don Bragg and partners are working to better understand the ecology of these open forest systems – as well as silvicultural practices to create, manage, and maintain them.
“Managers are looking to restore these open oak and pine forests and recover their goods and services,” says Bragg. “Understanding how the ecology and management goals differ from closed-canopy forests will help us apply the forest management treatments and tools that best create and maintain these conditions.”
The team synthesized recent research and case studies to highlight available silviculture options and identify knowledge gaps. Open forest silviculture is focused on limiting woody plant regeneration and maintaining an understocked canopy. Prescribed fire is the most indispensable tool, but there are others that can be used to restore and sustain these conditions, including periodic harvests, herbicides, and targeted species planting.
“We have studied some systems, like longleaf pine, for decades, but still have much to learn about oaks and mixed composition forests. Our research on open forests continues – so we can address new questions from land managers and broad-scale challenges like invasive species and climate change,” adds Bragg.
This work builds on a previous study that conceptually modeled open forest interactions between disturbances, tree tolerance to fire and shade, and stand structure.