Wetland Soil Biogeochemistry at Depth within the Prairie Pothole Region.

Wetland ecosystems are influenced by agricultural practices. Due to complexity in evaluation and limited observations of chemical parameters within the surface substrate and landscape, soil chemistry in wetland assessment, monitoring, and mitigation is often overlooked. Prairie pothole region (PPR) landscape influences have been recognized but there is limited understanding of the influence on multi-element chemistry concentrations at depth, hence, a knowledge base of multi-element chemistry composition in PPR is needed which can aid in restoration of debilitated wetlands to suitable wetland ecosystem functions and provide information for future guidelines on wetland management. This study’s objectives were to: 1) assess the vertical variation in multi-element composition of wetlands soils, and; 2) interpret the variation differences between undisturbed wetlands and disturbed wetlands. The field study was conducted on six disturbed and six undisturbed North Dakota PRR wetlands. Preliminary results of environmental variables determined by manual forward selection procedure with Monte Carlo permutation tests (p<0.05) (ter Braak and Šmilauer, 2002), generated RDA (Redundancy Analysis) models of element concentrations to a 1m depth in disturbed and undisturbed wetlands. The ordination plots of RDA of element concentrations in undisturbed wetlands to depth of 1m was constrained by one set of variables (OM, % sand, EC, site location, pH) while in disturbed wetlands, a different set of variables (EC, bulk density, OM, pH, and depth) showed constraint. Pearson correlation coefficients of select soil physical properties correlated with the five most prominent soil elements differed between the disturbed and undisturbed wetlands. This research indicates that anthropogenic impacts on the disturbed wetlands have influenced the subsurface hydrology related to the physical and chemical properties, which differ from the undisturbed wetlands. These differences appear to be related to the vegetation and soil health of surrounding landscapes.