| In southwest Costa Rica 11 sites representing a chronosequence of formerly pastured lands to undisturbed forests, and one tree plantation were selected for application of the hydrogeomorphic approach, a tool designed to assess wetland functions in the U.S. Models for the maintenance of characteristic soil hydra-structure condition and maintenance of spatial structure of habitat were developed and used to examine the degree to which selected sites within the chronosequence depart from the undisturbed condition of the natural forest. An index of the function showed for the maintenance of characteristic soil hydra-structure that the 20-year-old forest is ca. 60 percent of the condition of the undisturbed sites; 4-year-old forest and 6-year-old plantation presented similar index values, ca. 40 percent of the established standards, followed by 10-year-old-forest and active pasture. The maintenance of spatial structure of habitat showed that 20-year-old-forest, 10-year-old-forest and the plantation held similar index values greater than 4-year-old and active pasture and were approximately halfway to reference conditions. These results show that functional assessment can be a useful technique for restorative programs in the tropics. |
