Characterization and Classification of Seaside—Salt‐marsh Soils on Virginia's Eastern Shore

Abstract

AbstractSalt marshes, historically, were considered to be of minimal value. Current concepts consider these marshes to have a very high biomass. This study was conducted to characterize soils in seaside salt marshes on Virginia's eastern shore and to classify them according to criteria in Soil Taxonomy and proposed amendments. Results indicate that salt‐meadow marshes, dominantly vegetated by saltmeadow hay (Spartina patens), contain soils with halmyric and nonsulfidic properties and aquic moisture regimes. Classification of these soils as members of the proposed Halmyraqualfs will necessarily broaden the definition of halmyric materials to include an aquic moisture regime and the definition of the argillic horizon to include sodium adsorption ratios (SARs) considerably >13. We propose that soils in these marshes with subsoil illuvial clay accumulations and SARs >13 be classified as members of Typic Natraqualfs even though they lack structure currently defined for natric horizons. Saltmarsh cordgrass marshes, dominantly vegetated by S. alterniflora, contain soils with halmyric and sulfidic properties, silty textures, and peraquic moisture regimes. Tidal mudflats, not vegetated by vascular plants, contain sediments that have halmyric, but dominantly nonsulfidic properties. These results indicate that conditions necessary for the formation and accumulation of sulfide minerals exists in the salt‐marsh‐cordgrass marshes and to a limited extent in the tidal mudflats and in the salt‐meadow marshes. Considerably more information concerning properties of all the soils in the study area is conveyed by the proposed halmyric great groups and subgroups than by taxa currently defined by Soil Taxonomy. Moist incubation of samples provides a convenient and economical method for evaluating soils and sediments as sulfidic materials. Results of this study support the need for the proposed amendments to Soil Taxonomy.