A reserve is not always so good: change in landscape management after protection negatively affects the floristic diversity of an urban park

The aim of this study is to analyze the floristic changes occurred between 1991 and 2018 in the “Pineto Urban Regional Park” (Rome) as a result of a land-use change that in mid-90s led to the abandonment of traditional pasture practices and a shift to a more intense frequentation for recreational purposes. About 25 years after the change in management the area has a similar floristic richness, but it is characterized by a high turnover rate, a significant homogenization of the flora and a change in the community structure with a higher level of dominance. The removal of the pasture, which has favoured an increasing frequentation by people, seems to be the main driver of these changes. We suggest that a more active management, with the reintroduction of a sustainable grazing and a limitation of the fruition in marginal areas close to the urban matrix, could restore an higher diversity and reverse the homogenization processes detected in this study and at the same time ensure the citizen fruition.