1. Technological Center; Federal Univ. of Santa Catarina; state of Santa Catarina 88040-400 Brazil
2. USDA-ARS, Grassland, Soil and Water Research Lab.; Temple TX 76502
3. Dep. of Soils; Federal Univ. of Santa Maria; state of Santa Catarina 97105-900 Brazil
4. Dep. of Geology; Baylor Univ.; Waco TX 76798
5. Dep. of Computational Landscape Ecology, UFZ Helmholtz Centre for Environmental Research; Leipzig Germany