Soil differences between extant serpentine oak savanna and grassland in Soldiers Delight Natural Environment Area, Maryland

Soil parameters were compared between serpentine oak savanna and grassland in Soldiers Delight Natural Environment Area, Maryland. Soils were analyzed for texture, depth to bedrock, bulk density, magnesium (Mg), calcium (Ca), aluminum (Al), nickel (Ni), potassium (K), iron (Fe), phosphorous (P), and acidity or alkalinity (pH). Oak savanna occurred on silt loam (61% silt) and grassland on sandy loam (64% sand). Silt loam had significantly greater depth (mean depth > 900 mm) than sandy loam (mean depth < 100 mm) and 50% higher fine soil bulk density. Rock fragment content was high in sandy loam (0.46 kg kg −1 , 0.20 m 3 m −3 ) and very low in silt loam (0.01 kg kg −1 , 0.01 m 3 m −3 ). The Mg:Ca ratio was not significantly different between soil types, pH was high for both soils (5.8 to 6.7), and bioavailability of Ni was probably not important ecologically. Based on the results of this study, soil physical properties contribute to vegetation differences between these soil types and not soil chemistry. Very shallow soil depth and high rock fragment content probably inhibit woody species establishment and development on sandy loam. However, based on the historical literature, woody plants may become established on sandy loam not excessively shallow for root system development.