A Botanical Survey of Madagasar's Endangered Littoral Forest

Missouri Botanical Garden, Saint Louis MO

Investigators

Abstract

A Botanical Survey of Madagascar's Endangered Littoral Forests This project involves a detailed botanical survey of selected littoral forest areas along Madagascar's east coast in order to compile a comprehensive checklist of the plant species that occur in this highly threatened ecosystem. Littoral forests on sand were once widespread and continuous along the coastline, but are now reduced to small, isolated patches that cover less than 1% of this island nation and continue to be degraded by intensive human exploitation. Despite their small size, however, these forests probably contain well over 1,000 native plant species, or about 10% of the total Malagasy flora, and many of them are restricted to this very specialized and localized ecosystem, occurring nowhere else on Earth. A team of U.S. and Malagasy botanists will systematically visit six representative littoral forest sites distributed along the ca. 1,500 km coastline, covering nearly 12 degrees of latitude. The flora of the study sites will be fully documented though the collection of dried herbarium specimens (ca. 1,400 per site); digital color images will be taken of 30-40% of the species, and information will be gathered on local uses and threats to the forest areas. The herbarium material will be identified and compared with historical collections made during the last 150+ years and stored in major institutions in St. Louis, Madagascar, and Paris, France (which has the largest collection of Malagasy plants). Critical specimen data (e.g., species name, geographic location, date of collection, etc.) will be compiled and made available on the Internet as a Survey of the Vascular Flora of the Humid Evergreen Littoral Forests of Madagascar, with a summary list and statistics for each site, and an integrated mapping capability for individual species, often accompanied by digitized images. The results of this study will greatly improve our knowledge of Madagascar's highly threatened littoral forests. Many species new to science will likely be discovered during the project, and hundreds more will be documented for the first time in decades, including many now threatened with extinction and therefore of critical conservation importance. Using data from the study we will evaluate whether species composition changes from north to south along the coastline. Preliminary data suggest that most species are restricted to only a portion of the littoral forest ecosystem, with gradual changes in species composition along a latitudinal gradient. If this hypothesis is proven to be correct, we will identify specific areas where the establishment of protected areas (parks or reserves) would collectively ensure the continued survival of the unique plants that comprise Madagascar's littoral forests.