On the field, Laurent and I harvested pieces of plants if they were not identifiable. Indeed, in the sampled plots, we noted all species. The aim is to obtain the complete list of plants in each plots. This step will allow us to analyze the impacts of butterfly bush on the vegetation succession (bare soils > grasslands > large herbaceous > … > forests).

To identify the plants, we use different tools. Among these tools, there are several books as systematic floras or illustrated identification guides. Moreover, we use reference herbarium containing species harvested from previous studies realized in quarries. Finally, for the most difficult plants, we ask the help of a botanist.

When plants are identified, we register data in an excel file. This file will be used for statistical analyses. For example, we are going to analyze the specific richness between plots with butterfly bush and without. This analysis will be made in three classes of butterfly bush ages. Moreover, we are going to analyze also the recover of bush or tree species in the two types of plots. This analysis aims to observe if the butterfly bush accelerates or not the vegetation succession.