Trees in agricultural landscapes: understanding past changes for a better management strategies

International audienceHabitat temporal continuity influences plant and animal communities and species spatial distribution, according mainly to their dispersal capacities and lifespan. Considering habitat history to the long and mid-term is then crucial to understand thow past landscape changes affect current biodiversity patterns. Moreover, the knowledge of the socio-economic causes of past landscape changes allows a better anticipation of their future changes and more efficient habitat or landscape management strategies. We thus reconstructed the history of rural forests in an agroforestry landscape in South-Western France, composed of farm forests and trees outside forests. Thanks to retrospective photo-interpretation of airborne images, we traced back and quantified their evolution from 1962 to 2010. We first attempted to understand both ecological and sociological determinant factors of these rural forest changes illustrated here for hedgerows. We focused on their location within exploitations and showed how changes are dependent of farm dynamics but also patrimonial and cultural backgrounds. We underline as well their potential contribution as ecosystem services providers (windbreak and erosion). Second, in order to detect whether changes in structural farm forest connectivity translate into changes in functional connectivity, we assessed its dynamics for plant species differeing by their dispersal capacities