Spatial Distribution of Soil Properties in Water Conservation Area 3 of the Everglades

Abstract

The need to integrate environmental responses at the landscape scale is a reoccurring theme in biogeochemistry and ecology. This linkage can be addressed by using geostatistics to examine spatial patterns and then assessing the relationships of these patterns to known ecosystem drivers. In this study, we used a stratified random sampling design to collect soil cores from 388 sites to quantify the spatial distribution of soil properties in a 233 000 ha subtropical wetland, Water Conservation Area 3 (WCA-3). To reflect hydrologic boundaries within the system, WCA-3 was divided into three zones: 3AN, 3AS, and 3B. Interpolated maps indicated that the highest levels of bulk density were located in western 3AN, whereas the highest total phosphorus (TP) values were located in northern 3AN and in areas adjacent to a canal bisecting the area. Twenty-five percent of 3AN had TP concentrations in the 0-to 10-cm layer . 500 mg kg 21 , indicating enrichment beyond historic levels. Only 5% of 3AS and 6% of 3B showed TP . 500 mg kg 21 . Total nitrogen (TN) and carbon (TC) were lowest in western 3AN, whereas the rest of WCA-3 had higher and more homogenous TN and TC distributions. Overall, distributions of soil properties were more homogeneous in 3AS than they were in 3AN or 3B. The approach used in this study provides a model for assessing current impacts to WCA-3, supplies baseline conditions against which future restoration efforts can be evaluated, and could be used in other landscape-scale wetland restoration projects.

Recent Changes in Soil Total Phosphorus in the Everglades: Water Conservation Area 3

“…Grid spacing was finer in the northern and eastern sections of WCA-3 that were expected to be impacted by nutrient inputs and coarser in the more pristine southern and western sections. During the resampling in 2003, 388 soil cores were collected from WCA-3 with a stratified random sampling design (Bruland et al, 2006). Predetermined sampling sites were located in the field with a global positioning system mounted to a helicopter.…”

“…In some cases it may be more appropriate to express data on a concentration basis (Bruland & Richardson, 2004), while in other cases it may be more appropriate to express data on a volumetric basis (Smith, Newman, Garrett, & Leeds, 2001). Using concentration units avoids the problem of multiplying precise numbers derived from laboratory analyses by more uncertain bulk density (BD) data (Bruland, Grunwald, Osborne, Reddy, & Newman, 2006). However, volumetric data perhaps allows interpretation from more of an ecological perspective as microbes and plant root systems occupy soil in three-dimensional space rather than by weight (Smith et al, 2001).…”

Inundation and groundwater dynamics for quantification of evaporative water loss in tropical wetlands

“…To study the reasons for the different inundation dynamics was beyond the scope of this study. One explanation may be the differences in the micro-topography together with soil types that either impede or accelerate infiltration, and therefore the drying process at a specific location (Bruland et al, 2006). Furthermore, local and regional groundwater fluxes, already observed in the study area (Schwerdtfeger et al, 2013), could also be the reason for discontinuous water level declines or mixing of water level signals induced by lateral connectivity between the water bodies (Tamea et al, 2010).…”

Carbon pool trends and dynamics within a subtropical peatland during long-term restoration

“…Both WCA-2 and WCA-3 surface hydrology is controlled by a system of levees and water control structures along the perimeter. Additionally, canals, levees, and water control structures bisect WCA-3 effectively dividing the area into four hydrologically distinct areas (DeBusk et al 2001;Bruland et al 2006). Soil within the WCAs are histosols and encompass both Loxahatchee and Everglades peat formations with depths ranging from~1 to 2 m with a mosaic of aquatic sloughs, expanses of wet prairie, strands of sawgrass (Cladium jamaicense Crantz), and patches of brush and tree islands (Gleason et al 1974;Brandt et al 2000;DeBusk et al 2001;Bruland et al 2006) Source of data Water quality data was retrieved from the South Florida Water Management District (SFWMD) online database (DBHYDRO; www.sfwmd.gov/dbhydro) for sites within the WCAs identified in Fig.…”

“…However, hydrologic restoration efforts and the construction and operation of the Everglades STAs have reduced storm water inputs and TP into WCA-2 (Julian 2015). Unlike the other two WCAs, WCA-3 is hydrologically and physically compartmentalized, resulting in a mosaic of areas with drastically different hydroperiods (north versus south), nutrient inputs, and cycling patterns Bruland et al 2006). The strength of the groundwater connection within WCAs is variable as is the thickness of peat/soil and depth to the lime rock bedrock across the landscape (Scheidt and Kalla 2007).…”