The Industeel France ArcelorMittal metallurgical slag heap with an area of 4 ha should be soon phytostabilised. The task 5.4 will be dedicated to the annual assessment of the efficiency of this phytomanagement strategy. This will be performed from year 1 to year 3 of the project.
The percentage of vegetation cover of the area will be estimated from observations made during the optimum growing season (June). For this, the study area will be divided into plots of 100 m2 (10 m * 10 m). Recovery will be estimated on a number of plots equal to 10 % of the whole area, arranged along transects positioned according to the apparent heterogeneity of the entire site.
These first results will also allow selecting a few vegetated plots differing in their percentage of plant cover and/or plant communities. These plots will be analyzed in detail with respect to the abundance/dominance of each species to calculate conventional indices of biodiversity: species richness (S = total number of species), species diversity (H = Shannon index) and equitability (EH). This study will be conducted three times in the second year of the program to include vernal, summer and fall species. The results will be used in the framework of actions foreseen in task 2.3 (site mapping). The objectives of this action are:
- identifying and characterizing the possible heterogeneities in the process of plant recovery ;
- assessing the efficiency of phytostabilization of metallurgical dump at a large site scale.