Protected areas such as national or provincial parks help to conserve ecosystems and their biodiversity. However, few studies have evaluated the effect of land conservation in the private sector in maintaining ecosystems and biodiversity. In recent years, the Réseau de Milieux Naturels Protégés (www.RMNnat.org) has developed a unique, yet still underexploited database, georeferencing most of the protected areas on private lands in Quebec. For its part, the Canadensys network has a large open database of species occurrence, and the Quebec Natural Heritage Data Center (CDPNQ) can provide data on endangered, vulnerable or potentially designated species. By coupling data on Quebec flora from Canadensys and the CDPNQ to data on protected areas from the RMN, we wish to test the effect of private land conservation on several components of biodiversity (eg, alpha and beta biodiversity) through spatial and statistical analyzes.