Regeneration of the Robinson Crusoe’s island original Forest (Juan Fernández Archipelago, Chile)

Summary

The Juan Fernández Archipelago National Park, and World Biosphere Reserve, is composed of three oceanic islands located 680 km west of continental Chile at 33º S. Its biota and in particular the flora is characterised by its diversity and high degree of endemism (63,9%), resulting from a long process of local evolution without anthropic influence. The Robinson Crusoe Island (RCI) is the only permanently inhabited of the archipelago, presenting human influence since 1574 (629 inhabitants). From this moment on, fires, selective cuttings and the introduction of exotic species of flora and fauna have affected enormously the forest communities. Currently 75% of the endemic vascular flora is considered in verge of extinction, being urgent its conservation. The original forest communities of the RCI constitute an important part of the endangered species habitat. Unfortunately there is still unclear the natural ecology of the dominant tree species. This evidence is crucial to consider in any conservation and restoration proposal.
The objective of this study is to analyse where occurs the regeneration of the main tree species of the RCI original forest (Myrceugenia fernandeziana (Hook. & Arn.) Johow, Fagara mayu (Bertero ex Colla) Engl., and Drimys confertifolia Phil.). Using a forest area as case study (Plazoleta el Yunque sector) it will be assesed i) if the regeneration follows a light gradient, ii) if the species demand certain characteristics on its regeneration habitat (e.g substrate, rocks, coverage) and iii) how the main weeds (Aristotelia chilensis (Molina) Stuntz, Rubus ulmifolius Schott) affect the natural regeneration in gaps. As expected outcomes is considered the understanding of regeneration niche characters for the main tree species, and the identification of key site aspects (indicators) for the original forest self replacement. This knowledge might contribute basic information, to propose further conservation and restoration activities for this ecosystem.