The King Farm: a case study in the effect of agricultural legacies on forest change dynamics
Forests regenerating from abandoned agricultural land display legacy effects in soil and species composition that persist long after human land use ceases. Plant communities that recolonize these areas reflect previous land use and other intersecting influences often creating novel ecosystems that do not resemble forest composition prior to anthropogenic clearing. Small abandoned farms dot the Southern Appalachian landscape, and we have examined one such area where a blend elements including persisting soil legacies and proximity to seed sources have created one such novel ecosystem. We sampled tree communities and soil nutrients of plots within and surrounding a former agricultural site on the Cumberland Plateau that has been regenerating for approximately 70 years. Communication with former inhabitants of the farm revealed specific land use decisions, including use of soil amendments, that elucidated causal factors driving these specific soil legacy effects.
Leighton Reid, Missouri Botanical Garden
Callie Oldfield, University of Georgia
Presented Paper (abstracts linked):
Evans, J.P. 2017. A Place on the Plateau: 200 years of land-use change and forest ecology at the King Farm on the Domain. Second Annual Interdisciplinary Conference: A Sense of Space and Place: Global and Local Perspectives. The University of the South, Sewanee, TN. (April 6–8).
*Block, A., J.P. Evans and *L. Reid. 2016. The role of agricultural legacies in generating novel plant communities in nutrient-limited forests: A case study from the southern Cumberland Plateau, TN (USA). Annual Mtg of the Botanical Society of America. Savannah, GA. (July 30 - Aug 3).
Magnesium, calcium, phosphorus, and pH of soil within the previous farm were significantly higher than plateau soils outside the farm, though more similar to environmental conditions in the cove. The vegetation community within the farm presents a unique blend of species found in both the cove and plateau environments, even though compositionally these communities are distinct in the surrounding landscape. The interplay of legacies, specifically persisting soil nutrient differences that resemble environmental conditions of the cove, and the seed sources for regenerating plants have led to a novel plant community that is more similar to that of the adjacent cove forest than to the surrounding plateau forest. Human alteration of the landscape in the form of agriculture has been common across the southeast; due to changing land use practices, areas that were historically farmed are reverting back to forests. This study is an illustration of how agricultural legacies can alter the direction of forest change within native ecosystems resulting in the creation and long-term persistence of novel plant assemblages.