A powerful way to identify the geographical locations and habitats favoured by the target taxon is to produce distribution maps showing the location of collecting sites and the data obtained, including data derived from statistical analysis. These distribution maps can be superimposed on topographical, climate, geological or soil maps.

There are three approaches that can be taken:

• Enclosed Line maps - shading or enclosing an area with a single line to show the distribution of the target taxa.
• Dot distribution maps - presence is indicated using dots on the map
• Contour maps - e.g. isoflor map: distribution of plant taxa indicated by joining together points which have the same number of taxa.

Copyright © 1997, International Plant Genetic Resources Institute.