Progress towards a floristic inventory of the coastal savannas of French Guiana
By P.G. Delprete, R.E. Bone & G. Lolli
The coastal savannas of French Guiana occupy a narrow strip (ca. 4-7 km wide) along a 150 km stretch of coastline from Cayenne to Organabo. They represent the most endangered habitat in French Guiana due to increasing human pressure, as the vast majority of the population is concentrated along the coast. These savannas are commonly assumed to have low biodiversity and the flora has historically been estimated to comprise 250-300 plant species.
However their floristic composition remains poorly known, as most botanical and ecological studies in French Guiana are concentrated in forested areas. In late 2009 we began a floristic inventory of this threatened habitat with the main aims of producing a comprehensive checklist of the angiosperm and pteridophyte flora, and a regional conservation assessment. Additional aims include the development of a floristic field manual, a project website and a book of landscape photographs and representative species for a general audience.
The work to date has included a study of the specimens (most of them annotated by specialists) present at the Cayenne Herbarium (CAY) and six months of field work which has produced 1,200 additional geo-referenced collections and associated high-resolution digital images. As a direct result of detailed exploration of the savannas, areas not previously visited by botanists have been collected, and many new species records. The resulting database has a current total number of 4,230 entries, and includes 60 families, 120 genera and 630 species. Our preliminary checklist therefore more than doubles the estimated number of plant species reported in the historical literature, emphasizing the rich biodiversity of this often neglected habitat, which is in urgent need of protection.
Key words: French Guiana, coastal savannas, checklist, floristic inventory, conservation.
This work was presented by Piero G. Delprete at the Flora of the Guianas meeting and workshop, at the Herbarium of the Smithsonian Institution in Washington DC, U.S.A. (4th and 5th of November, 2010).