CONCEPTUALIZED TOPOSEQUENCE OF LAGUNA ATASCOSA NATIONAL WILDLIFE REFUGE IN SOUTH TEXAS

Laguna Atascosa National Wildlife Refuge is the largest protected area of nature habitat in the Lower Rio Grande Valley of Texas. This area is an exclusive complex coastal margin system located 25 miles north of Brownsville along the hypersaline Laguna Madre and is managed to preserve the natural diversity and abundance of an ecologically important mix of waterfowl and wildlife with over 400 species of native, wintering, and migratory birds. Understanding the landscape changes in this region is important for the preservation of this unique habitat. Local impacts influence the health of coastal ecosystems, in response plant community fluctuate in population and distribution. The primary anthropogenic threat to the ecological integrity of natural communities has been the increased development of the surrounding coastal areas. The land-use in the Lower Rio Grande valley is increasingly changing from agriculture to commercial and residential development. These land changes have redirected the natural drainage patterns and have reduced the amount of fresh water flowing into the region. Visualization is important for understanding these changes and can be used for land management, environmental resource monitoring, and predicting changes to coastal vegetation patterns where water availability and soil salinity both impact plant community locations and ultimately the wintering and migratory bird populations. A toposequence, or profile, was created by correlating topography, soil type, soil conductivity, and vegetation based on site similarities