Institute of Botany and Botanical Garden, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
The Juan Fernandez Islands (or Robinson Crusoe Islands) are situated about 360 miles west of continental Chile in the Pacific, at 330 S latitude. The archipelago is of volcanic origin and has never been connected to the mainland. It comprises the two large islands Masatierra and Masafuera (Alejandro Selkirk), and a smaller one, Santa Clara, close to Masatierra. The large islands are separated by c. 90 miles. The archipelago harbours a unique flora of c. 423 vascular plant species, with endemism among native elements of 60% at the species and 11% at the generic level. Major threats to this flora such as goats, alien plants, and deforestation have led to the reduction of natural vegetation and forest areas. Thus, numerous endemic species of the Juan Fernandez Islands are critically endangered. The island Masatierra covers an area of 48 km2 and consists of a low western part and a central-eastern part with high mountains and deep valleys. Erosion is a problem, especially in the dry western part which is covered mainly by secondary grassland. Native Stipa grassland is found on the steep coastal regions of the central and eastern part. Native montane forest also is located there, as moisture is caught by elevations up to 915 m (Cerro El Yunque). The vascular flora of the island is well known, with a complete new catalogue having appeared in 1999 for the whole archipelago (Marticorena et al., Gaysna Bot. 55: 187-211.). Presently funded investigations focus on providing a new vegetation map of the entire island. Masatierra is part of the Robinson Crusoe Islands National Park, administered by CONAF (Corporacion Nacional Forestal, Chile), and, therefore, already under permanent protection and supervision. Research is presently only possible through permit from CONAF, which then provides substantial logistical help in facilitating research activities. Protection and monitoring of a permanent vertical landscape transect area in Villagra Valley on Masatierra is likely to provide useful data for a comparison of ecological and biological features in the framework of the PABITRA project. It also could reveal important information for safeguarding the survival of endangered species of the archipelago. The recommended site for the transect is oriented NE to SW and leads from 50 m s.m. near the sea to 600 m s.m. It starts from very dry, disturbed habitats, leads upwards into native forests mixed with introduced species, and terminates in moist forests composed of native and endemic taxa. A path running through the valley provides convenient access for research purposes.
Abstract from: 43rd Symposium of the International Association for Vegetation Science, July 23-28, 2000, Nagano, Japan.
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Last Updated: 08/18/00