Land use and soil legacy in the Lower Coastal Plain: A case study of Wormsloe State Historic Site, Georgia

Abstract

Agriculture alters forest soil physical and chemical properties, often for decades to centuries, following agricultural cessation. Wormsloe State Historic Site, near Savannah, Georgia, has nearly a 300-year documented history of land use. To investigate agricultural soil legacies at Wormsloe, 120 random sample points were established across two land use history areas: Agriculture (some agricultural activity between 1736 and the present) and Reference (areas never farmed and under some forest cover from 1736 to present) within two mapped soil series (Chipley and Olustee). Landscape variables; profile characteristics; soil pH, carbon (C) and nitrogen (N) concentrations; extractable phosphorus (P), calcium (Ca), and magnesium (Mg) concentrations; and dominant vegetation were evaluated. An A horizon was always described in never farmed reference areas, and an Ap horizon was often, but not always, described in reforested agricultural areas. Soil P concentrations (Mehlich-1) were elevated (p = 0.05) in former agricultural areas. Soil pH (p = 0.04) differed across soil series but not land use. Discriminant analysis of sample plots reclassified by agricultural abandonment period (Reference/No Agricultural History, Civil War, Depression, and Modern) indicated that the Reference/No Agricultural History and Civil War period plots were similar and distinct from plots in areas abandoned during the Depression and Modern periods. Our ability to discriminate among dominant overstory and understory vegetation types using soil and site variables was relatively low.