OOS 40-3
Silviculture in southern pinelands: The role of experimental forests
In 1921, the US Forest Service (USFS) formally established a research program in the southern US and shortly thereafter opened a number of experimental forests (EFs) to help develop management techniques. This occurred at a critical juncture for the southern timber industry, as the virgin forest had been largely cleared and it was unknown if pine silviculture was even possible. Fortunately, applied ecology in southern pine-dominated timber proved economically viable and today many of these EFs continue to provide useful research. Of the dozen USFS EFs in this region that focused on southern pine-dominated forests, this paper will highlight five (Crossett, Escambia, Harrison, Olustee, and Palustris) with pivotal roles in silvicultural research. The primary focus on the Crossett EF (established in 1934) was the development of silvicultural guidelines for loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine on the Upper West Gulf Coastal Plain, while in the Lower Coastal Plain the Escambia (1947), Harrison (1934), and Palustris (1935) EFs focused on longleaf (Pinus palustris) and the Olustee EF (1931) featured slash (Pinus elliottii) pine.
Results/Conclusions
Initial southern pine management research often concentrated on the refinement of uneven-aged techniques that removed large-diameter sawtimber to provide growing space for shade-intolerant seedlings. Hence, natural regeneration dynamics were some of the first studies conducted, and successful investigations of seed production, germination ecology, stand establishment, and protection were instrumental in convincing people of the forestry potential of this region. This knowledge found immediate application in the large-scale reforestation of degraded agricultural and cutover lands. Longleaf proved harder to manage than the other southern pines, largely due to a more complex life history involving disturbance (primarily fire) and regeneration issues. Later work on naturally regenerated even-aged pine stands led to increased stand-level productivity and better integration with the dominant disturbance regimes.
Further studies on even more yield-oriented silviculture evaluated competition control, density management, and the use of genetically improved pine seedlings often had their origins on EFs. Recently, however, the consideration of ecosystem services of southern pine forests (other than wood production) has become one of the mission priorities of many EFs. This has come from new research or the reinterpretation of existing silvicultural studies, some of which have been in place for over 75 years. The spatial scale and temporal scope of the silvicultural research done on these EFs is invaluable to the growing body of ecological knowledge on southern pine-dominated forests.