Habitat Factors Influencing the Distribution of Small Vertebrates on Unmined and Phosphate-Mined Flatlands in Central Florida
We used representativeness as a means of comparing vertebrate wildlife species found on reclaimed phosphate mined land with vertebrate wildlife species found on unmined land in central Florida. Land properly reclaimed as wildlife habitat should support a flora and fauna that .represents. the native flora and fauna that existed prior to the mining. We identified the pool of resident species on unmined mesic flatlands (reference sites) for comparison with the species living on mined (reclaimed) lands. Those vertebrate species that are under- represented at reclaimed sites relative to their distributions and abundances at reference sites are identified as “focal species.” Soil characteristics and vegetation profiles were measured at each of the sixty study sites used for the vertebrate wildlife comparisons. Many soil and vegetation differences exist between the reclaimed and reference sites. The vegetation structure at reclaimed sites was different than the reference sites. All reclaimed sites lacked a Middle-Canopy layer, and were dominated by a few foliage layers. The resident species include 12 amphibian species, 17 reptile species, 6 mammal species, and 46 bird species. Twelve species including 1 amphibian, 2 lizard/turtle, 0 snakes, 0 mammals, and 9 birds are focal species; that is, these twelve species are found much more commonly at reference sites than reclaimed sites. Four bird species were found more frequently at reclaimed sites than at reference sites. We found that preferences for breeding sites (amphibians) or for vegetation structures (reptiles and mammals) could distinguish most of the focal species from the non-focal species. We found that vegetation structure alone could distinguish nearly all focal from non-focal bird resident species. The focal species all prefer wooded areas, some favoring areas with extensive tree canopy and others favoring areas with shrubs or low canopy, while the non-focal resident species almost all prefer open areas that are conducive to ground foraging.
We conclude that proper reclamation of mesic habitats will have to account for the high variation of species composition at a given site and incorporate a high degree of habitat heterogeneity. We suggest that existing patches of reclaimed mesic habitats are isolated from existing remnants of reference habitats as well as from other patches of reclaimed habitat. Wildlife would benefit if these patches were connected by additional reclamation. Likewise, wildlife likely would benefit if all upland reclamation efforts were tied to wetlands, both permanent and temporary. We support a broad regional approach to rehabilitating phosphate mined land for wildlife in Florida. A broad regional approach should include the entire Bone Valley and surrounding areas in Florida.