Uso de espécies nativas e exóticas na restaura??o de matas ciliares no Estado de S?o Paulo (1957 - 2008)

摘要

Ecological restoration in Brazil has intensified in recent decades, and its concepts and paradigms have progressively changed. In the first decades, the richness of species and their origin were not questionable, since the restoration was intended to restore only ecosystem services. Currently, however, high diversity is required and only native species are accepted by environmental laws. In order to verify if the numbers of native and exotic species used in ecological restoration have changed over time, we assessed 44 riparian forests undergoing restoration in the state of S?o Paulo. All study areas were restored from 1957 to 2008, in sites where the former vegetation was seasonal forest (FES). At each site we sampled all trees planted in a total area of 1000 m2, divided in plots randomly distributed. We classified as exotics all species whose native range is not the Seasonal Atlantic Forest. The total number of species sampled per site ranged from 12 to 58 and exotic species were recorded in all sites. The number of species recorded increased from an average of 25 species in the 1970s, 1980s and 1990s, to 33 species from 2000 to 2008. However, the number of alien species has also increased in the same period. Rules aiming at high diversity in ecological restoration may have been successful, but the use of exotic species in restoration projects have increased in recent years. Improving inspection in forest nurseries and adequate training of professionals involved in ecological restoration are recommended actions in order to avoid the use of exotic species in restoration projects.