Land use legacies and site variables control the understorey plant communities in Mediterranean broadleaved forests

This study aimed to assess the influence of the past land uses on modern forest ground vegetation communities by combining historical records with field sampling. The history of forest uses was inferred from historical and census records, and site variables and ground vegetation composition were collected and measured based on 42 plots within five forests situated on the French-Spanish border. Both site and land use variables explained the observed pattern of ground vegetation composition. The most important part of this variation was explained by the site variables that bring together environmental and habitat variables. The chief determinants of forest use were the historical forestry treatment and the historical dominant livestock. The species assemblage of forests historically grazed by cattle and treated as coppice selective system or without forestry practices for more than a century reflected high level of disturbances. On the contrary, the species assemblage of the forests historically grazed by sheep and that experienced coppice selective system or both coppice-with-standards and timber forestry treatment reflected a lower disturbance context. Finally, the forest historically grazed by both cattle and sheep and treated as coppice-with-standard revealed an intermediate level of disturbances.