Three factors are tested and controlled: stand composition, stand density and pressure of herbivory by ungulates. 3 replicates were installed for each studied combination of factors.
The factors of the experimental treatments:
- 3 compositions: pure oak (Quercus petraea), pure pine (Pinus sylvestris) and oak-pine mixture;
- 2 densities: a dynamic scenario and a conservative scenario. To control the density over the all life of the stands, the relative density index (RDI) is used (see figure). Two level of density are tested: RDI around 0.4 corresponding to the dynamic scenario and RDI around 0.7 corresponding to the conservative scenario;
- 2 types of herbivory pressure: open access and total exclusion with fences.
Stand composition and tree density have a completely crossed factorial design, while herbivory is completely crossed with stand composition only for the low tree density
The combinations of the factors tree density and herbivory corresponds to three unique management strategies: low density without herbivory, low and medium density with herbivory. The experiment is set up with three replicates for each unique combination of factors with a total of 27 plots (3 compositions x 3 management strategies x 3 repetitions).
In the case of mixed stands, additional treatments are tested:
- Control plot with no management actions (3 additional plots);
- Selective fences allowing the entry of wild boars but not the other ungulates (3 additional plots).
Finally, the experiment includes 33 experimental plots spread over 12 management plots.