Wednesday, November 7, 2007
325-8

Gis-Based Analysis of Physico-Chemical Soil Properties, Nutrient Influx Points and Vegetative Patterns Characterized by Field and Remote Sensing Data.

Tiffany Kapner1, Sabine Grunwald1, K. Ramesh Reddy1, Todd Z. Osborne1, and Susan Newman2. (1) Soil and Water Science, University of Florida, 2169 McCarty Hall, PO Box 110290, Gainesville, FL 32611, (2) South Florida Water Management District, West Palm Beach, FL 32611

A better understanding of the response patterns of soil-vegetative features that have been generated by internal and external forcing functions is in need. The objective of this study was to investigate spatial relationships between soil and vegetation patterns using field and remote sensing data. A total of 131 locations were sampled in Water Conservation Area 1 (WCA 1). Two layers (floc and 0-20 cm soil) were analyzed for bulk density (BD), total carbon (TC), total calcium (TCa), total nitrogen (TN), and total phosphorus (TP). A vegetation map was used to delineate vegetation types and a Landsat remote sensing image was used to delineate various spectral indices: Normalized Difference Vegetation Index (NDVI), NDVI green and Normalized Difference Water Index (NDWI) values. Geostatistical methods were used to interpolate site-specific soil properties across the study area. The GIS-based analysis comprised zonal statistics to calculate means and variance of floc/soil properties stratified by geographic features (buffers) at specific distances from nutrient influx structures, vegetation classes, and spectral values. High TP and TCa were associated with cattail, an invasive species, as well as geographic locations in proximity to nutrient influx structures. Total N showed little variation across WCA1 and no significant correlation with any vegetation species. The NDVI and NDVIgreen showed significant different signatures among open water, hardwood swamp and sawgrass marsh as well as cattail. The NDWI was well suited to distinguish between open water and vegetation classes but less so among different vegetation classes.