Subaqueous pedology and soil‐landscape model evaluation in South River, Maryland, USA

Using a subaqueous soil‐landscape conceptual model previously developed in an adjacent subestuary, a subaqueous soil survey was undertaken for the South River subestuary of Chesapeake Bay. Using available bathymetry, subaqueous landforms and soil map units were delineated prior to the initiation of any field work. To evaluate the predictive usefulness of the conceptual model, the study area was subsequently sampled at 52 points along specified transects. The soils were described and classified, and the observed soils were compared to the predicted soils from the model using a bootstrapping analysis approach. We concluded that the conceptual model did provide significant positive guidance to generate a useful soil map in South River, by successfully predicting the distribution of soil material types. It did not, however, address the distribution of hypersulfidic materials prevalent in South River soils. The additional information gained on the soils and pedogenic processes gained during this study were incorporated into the final soil survey for the subestuary, and they were also used to refine the soil‐landscape conceptual model to improve its potential usefulness in future mapping of western shore subestuaries of Chesapeake Bay. Core Ideas The soil‐landscape paradigm beneficially applies to relatively shallow (less than 8 m) estuarine environments. Subaqueous soil properties are associated with specific subaqueous landforms. The conceptual model used to predict soil distribution in South River was effective. Soil physical properties are superior to taxonomic groups as a basis for evaluating a soil‐landscape model.