VARIATION OF SOIL PROPERTIES ACROSS DIFFERENT HABITATS IN AN ECOLOGICAL PRESERVE IN BOCA RATON, FL. USING GROUND PENETRATING RADAR

The Florida Atlantic University Ecological Preserve, located in Boca Raton, Florida, is a host to three different Florida native habitats: tropical hardwood hammock, upland scrub, and dry prairie. These three habitats provide a sanctuary for species of conservation concern such as the burrowing owl and gopher tortoise. Although these habitats are fairly well characterized from an ecological perspective, little is known about how soil characteristics below the surface may influence habitat distribution. This study presents preliminary results of a soil characterization survey to better understand the role of subsurface physical properties on habitat occurrence. A set of non-invasive geophysical surveys using ground penetrating radar (GPR) combined with direct coring was conducted in each habitat to characterize subsurface properties. GPR was used to estimate changes in the vertical distribution of electromagnetic (EM) velocity at each site and its potential correspondence to changes in soil physical properties. Common midpoint surveys were used to estimate one dimensional distributions of velocity with depth, while common offset surveys were used to investigate the lateral extent of subsurface stratigraphy across habitats. An array of 50, 100, 200, 250 and 500 MHz antenna frequencies were used to investigate resolution and depth of penetration at each habitat. In order to validate GPR results, direct corings were conducted to confirm stratigraphic interfaces. Soil samples were collected at each habitat to further determine physical properties in the laboratory (i.e. porosity, moisture content, etc.). The results of this study have implications for better understanding the relationship between soil properties and the distribution of native plant species, and therefore may assist with efforts for protecting and restoring these important habitats.