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Protected areas (PA) have undergone a major paradigmatic shift over the past 30 years, from segregative to integrative models. Drawing on the literature on the transformation of social-ecological systems and Ostrom’s institutional analysis, we compare this evolution for two types of protected areas in France : national parks and nature reserves. Whereas the former are characterized by a top-down implementation of the integrative model, the latter present a more bottom-up integration. A comparison of empirical fieldwork conducted in two national parks and ten nature reserves highlights three key variables in the implementation of integrative approaches in PA : leadership, social capital and the three levels of rules-in-use (constitutional, collective and operational). By combining these three elements, PA managers are able to navigate in specific and ever changing social-ecological contexts towards integrative PA models. However, their leeway differs for national parks and nature reserves, depending on historical aspects, the impetus at the origin of transformation, and the scale effect.