CHARACTERIZING SPATIAL AND TEMPORAL HETEROGENEITY OF IRON-SULFUR INTERACTIONS IN A COASTAL FRESHWATER WETLAND

Biogeochemical soil variation can result from innate soil heterogeneity or induction by a driver such as salt water incursion. We visually quantified soil microbial patterns in chemically reducing wetland conditions using the Indicator of Reduction In Soils method (IRIS). We employed geostatistical methods to determine the range at which semivariance between sample points is highest and autocorrelation between points is lowest. The goal of this study is to determine the spatial extent of soil biogeochemical heterogeneity and distinguish innate heterogeneity from driver induced patterns. We ask, at what spatial scale do driver induced patterns (ex. salt water incursion) develop out of innate soil heterogeneity patterns in a coastal freshwater wetland? Preliminary IRIS data indicate the salt and fresh extremes of the site have differing geospatial extents in heterogeneity and driver induction. This method allows us to parse apart the confounding influence of incursion over intrinsic soil heterogeneity to accurately quantify driver effects.