JLE

Science et changements planétaires / Sécheresse

MENU

La mémoire des pâturages africains Volume 10, issue 3, Septembre 1999

Authors
CIRAD-EMVT/CNRS, BP 5035, 34032 Montpellier Cedex 1, France, INRA-INA PG, Unité d’agronomie, BP 01, 78850 Thivernal-Grignon, France.
  • Page(s) : 171-82
  • Published in: 1999

Optional modules provide access to flora distribution maps on a country and area (square degrees, windows or variable circular radiuses around a georeferenced point) basis. For each scale, the survey record distribution or records of unique species are given along with a list of records concerned or corresponding florula, classified by alphabetic or taxonomic code. A module analyses the distribution range of a species, determines the site coverage, the centre of the area, its surface area, perimeter and flattening. It is mapped and the centre is located. The areas can be compared two-at-a-time and their extents of sympatry can be assessed. Biodiversity is dealt with in terms of flora and vegetation. Flotrop provides biodiversity indexes on a per-station and-region basis. It takes the number of families, species and family distributions into account and calculates diversity by various formulas : floristic richness, Shannon’s computed diversity and Simpson’s probabilistic diversity. Another option supplies weighted pastoral spectra on flora (unweighted floristic inventory lists) and on vegetation. One module highlights observers’ inventory inputs on a territorial or general scale. The prospects : publishing the information on the Web to provide access to research scientists ; data acquisition in sectors where these data are not yet available ; analysis of other topics (biological).