Tree species richnessThe french territory encompases highly diverse climatic, geologic and topographic conditions, which leads to species-rich forests. Figure 1 represents the number of tree species per sample plot, for the inventory campaigns led between 2017 and 2021. It shows the local richness in tree species. The average number of forest tree species observed is 4. The Landes of Gascogne and the Mediterranean regions show the lowest tree species richness (between 1 and 5). The Landes of Gascogne forest is mainly covered by monospecific Maritime pine (Pinus pinaster) plantations; the Mediterranean region by evergreen oak (Quercus ilex) or pubescent oak (Quercus pubescens) coppices or Scots pine or Aleppo pine (Pinus halepensis) high forests. |
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| Shrub species richnessFigure 2 shows the number of shrub species per sample plot, for the campaigns 2017 to 2021. It indicates the local richness in shrub species. The number of shrub species is usually higher than tree species. This number varies from 1 to 26 and the average is 6.1. Unlike for tree species richness, the Mediterranean region has a high shrub species diversity. This is partly due to the important part of open canopy forest in this area. |
