The Louis-Marie Herbarium collection includes many old specimens useful for reconstructing the flora of regions in Québec that have undergone extensive transformations. For example, Claude Lavoie’s team (CRAD) used the herbarium to help reconstruct the flora of Bic National Park (Bas-Saint-Laurent, Québec), before and after its creation in 1984.

    Despite its small area (19 km2), the park contains 26.% of the vascular plants of Québec.The comparison of old and recent floristic lists was possible thanks to the plant records of numerous botanists who had visited the park including Merritt Lyndon Fernald, Jacques Rousseau, and Homer John Scoggan. These comparisons made it possible to accurately evaluate the losses and gains in the total number of species, as well as changes in the flora, particularly those concerning exotic species.