Santa Clara Island is a small island (221 ha) 1.6 km away from the tip of Robinson Crusoe Island and 667 km from mainland Chile. Santa Clara Island (SCI) is a high grassy plateau with no open sources of water, and was thus never settled by humans. However, goats, sheep, and rabbits were introduced to the island at various times since discovery by humans in 1574. The original biota is unknown because there are no botanical records prior to the introduction of goats. In 2003, the last of the exotic mammals were exterminated from SCI in the hope that the native and endemic biota would reestablish. To determine whether native biota reestablished, we conducted two plant identification visits to the island in 2005 and 2012 where we used transects and percent cover quadrats to collect lists of species and abundances. We also searched the literature to determine the known historical composition of plants.
Results/Conclusions
The native and endemic species of Santa Clara Island have not reestablished since the extermination of exotic mammals on the island. Nor have additional native or endemic species been found on SCI since 1955. We found fewer native and endemic species than did Skottsberg in 1955, however he surveyed areas that we could not access. Native and endemic species are also reported to have survived on the hard-to-reach cliffs and the sea mounts near the island that exotic mammals never reached. From our investigation, it appears that the flora of SCI has not changed over the last 60 years. Even though native and endemic flora may have survived in pockets, it does not appear to be reestablishing on the main plain of the island. Santa Clara Island appears stuck in an alternative stable state that will require intervention if native species are to become dominant again.