Longleaf pine (Pinus palustris Mill.) ecosystems are an icon of the southeastern United States; however, the amount of forests containing these long-lived trees, until recently, has been in decline due to development and conversion to “off-site” (i.e., wouldn’t be there naturally) pine plantations. The Department of Defense has been aggressively restoring the longleaf pine ecosystem on its lands for 20 or so years, not only to meet listed species needs but also to improve training realism and the sustainability of its training and testing landscapes. Managing for carbon storage is potentially the next challenge. In 2011 SERDP initiated projects researching the fundamental and applied science required to manage and restore forested ecosystems on DoD lands in the context of improving our understanding of carbon cycling in such ecosystems and the trade-offs involved in managing for carbon storage versus other ecosystem services.

One of these projects, RC-2115, Developing Tools for Ecological Forestry and Carbon Management in Longleaf Pine, is led by Dr. Lisa Samuelson at Auburn University and includes investigators from the University of Florida and the U.S. Forest Service. Dr. Samuelson and her project team are developing a modeling system capable of simulating the “typical” longleaf pine restoration sequence. For their modeling approach they start with planted, even-aged stands that are subjected to multiple thinnings and eventually the development of an uneven-aged structure dominated by single-tree, gap-phase dynamics. Project investigators accomplish this by parameterizing and coupling an even-aged longleaf pine model (growth, yield, and carbon balance model) with a gap phase, single-tree longleaf pine model that can simulate carbon dynamics in response to a range of forest management actions. A first version of the even-aged model is ready and available for foresters and land managers. This model can be run for forests with trees up to 80 years of age, under different management scenarios (planting density, thinning, and prescribed fire regimes), and with different site quality inputs (i.e., site index).

The even-aged longleaf pine model can simulate growth and yield (including stand parameters such as basal area, volume, and biomass) and merchantable product partitioning. The model can be used to evaluate stand responses to different thinning and/or fire regimes, which enables a variety of analyses. Wildlife habitat can be assessed by using the model to determine the time and intensity of thinning that can produce the desired stand structure at a given target age. The effects of forest management on carbon sequestration, including above ground, belowground, forest floor, and detritus pools, also can be modeled. This modeling system will help DoD land managers sustainably manage, restore, and protect these ecosystems that provide important habitat for a number of threatened and endangered species while meeting multiple management goals.

The growth, yield, and carbon balance model parameterized for planted and natural even-aged pine stands can be found at the Carbon Resources Science Center’s web site. A virtual workshop on the models will be held by project investigators in the summer of 2014. For more information on the workshop, please contact Dr. Lisa Samuelson (samuelj@auburn.edu) at Auburn University’s School of Forestry and Wildlife Sciences.

SERDP and ESTCP will continue to post the results of this project as well as the other ecological forestry and carbon management projects as they become available. A complete listing of funded projects and project overviews can be found at SERDP and ESTCP’s Ecological Forestry web page.