Spatial distribution

Click to display the number of species in the cell.

Conservatoire Botanique National Méditerranéen & Conservatoire Botanique National Alpin (


Click to display the ten species that contribute the most to the bioregion. Among the species that contribute to the bioregion, the sum of the contribution of all the plants is 100% .

Bioregions' relationships

Network of interactions between bioregions

For a given bioregion, the values (expressed here in percentage) show how the contribution of species that contribute significantly to this bioregion is distributed across bioregions (including itself). Only links with values higher than 10% are shown. More details available in the paper.

This interactive web application has been designed to provide an easy-to-use interface to visualize multiscale biogeographical structures of plant species distribution in the south of France. It was developed as part of a research project funded by the French National Research Agency through the Netcost Young Researchers project and by the French Ministry for an Ecological and Solidary Transition.

The first tab presents the dataset used to perform the analysis and the spatial distribution of plant species. The second tab displays a map of the bioregions identified with different methods. Other historical biogeographical delineation, such as the one proposed by Lamarck & De Candolle in 1805, are also available. The third tab presents the specificity of the bioregions and the relationship between them. The results are available at two different scales with grid cells of 5x5 and 10x10 km2 and several aggregation methods and similarity metrics have been tested (more details given below).

Aggregation methods

Two clustering technics have been applied to identify biogeographical regions according to similarities of species composition between grid cells.

  • OSLOM is a clustering algorithm designed to detect network communities
  • Ward's method is a criterion applied in hierarchical cluster analysis

Similarity metrics

The (dis)similarity of species composition between grid cells has been measured with the Jaccard and Simpson similarity coefficients.


Lenormand et al. (2019) Biogeographical network analysis of plant species distribution in the Mediterranean region. Ecology & Evolution 9, 237-250.


Maxence Soubeyrand & Maxime Lenormand


Source code available here


Coded under License GPLv3