Spatial Characteristics of Soil Properties along an Elevational Gradient in a Carolina Bay Wetland
1996
Reese, Rachel E. | Moorhead, Kevin K.
Soil chemistry gradients exist in wetlands but information on the spatial variability of wetland soil properties is limited. Soils were collected from a small, depressional wetland (Carolina bay) in South Carolina to determine spatial patterns along an elevational gradient. The bay was divided into four quadrants and a transect was established in each quadrant. Plots were sampled at every 10-cm rise in elevation along the four transects. Samples from the A and B horizons were analyzed for soil texture, organic carbon (OC), pH, cation-exchange capacity (CEC), and exchangeable Ca, Mg, and K. Significant difference were noted for OC, clay content, CEC, and base saturation for the A horizon across the elevational gradient. The OC content of the A horizon decreased from 4.7% in the center of the bay to 2.7% near the rim. The CEC decreased from 26.0 cmolc kg⁻¹ in the center to 13.9 cmolc kg⁻¹ near the rim. Significant differences also were observed for pH, OC, CEC, sand, silt, clay, exchangeable Mg, Ca, and base saturation among the four transects. In the B horizon, there were no significant differences for any parameter across the elevational gradient, or among the four transects. The clay content of the B horizon was about 20%, compared with <10% in the A horizon. The differences in soil parameters in the A horizon may be a reflection of vegetation patterns or hydrology of the bay. Sampling protocol for soils of depressional wetlands may require an evaluation of elevation, hydrology, and vegetation patterns to determine spatial patterns of nutrient cycling.
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