Viticulture abandonment benefits the bird community of the French Mediterranean

Abstract

Intensively managed viticulture dominates vast landscapes in the Mediterranean, but considerable vineyard abandonment has been observed over the past two decades. The effect of vineyard abandonment on biodiversity is poorly understood, making it difficult to assess the restoration potential of this common land-use change.

We assessed biodiversity responses to vineyard abandonment in Vaucluse, Southern France, using birds as indicator group. We compared bird abundance and diversity in a sample of 64 vineyards, pairing 16 currently managed vineyards with 16 recently abandoned and 16 managed with 16 longer abandoned vineyards. We used mixed models and multivariate techniques to establish relationships between bird diversity and structural attributes of the habitats, and we derived management-specific population densities in a distance sampling approach.

Long-abandoned vineyards hosted three times more species and showed a 3.6 times higher total bird abundance than managed viticulture. More recently abandoned vineyards had intermediate species numbers and abundance. Species richness patterns were not modulated by landscape composition and configuration, but higher abundances were found in landscapes with intermediate size of land-cover patches (i.e. field size). In managed vineyards, bird abundances were extremely low, with the exception of Woodlark Lullula arborea, which reached its highest abundance in managed vineyards. The bird community on abandoned vineyards shifted towards forest and woodland shrub species, likely driven by secondary succession, namely shrub encroachment and tree establishment.

The strongly positive effects of land abandonment might be due to the fact that only single vineyards (not entire landscapes) were abandoned, thereby increasing habitat heterogeneity at the landscape scale. The future state of the old abandoned vineyards is difficult to predict. As of yet, the abandoned vineyards support a comparably diverse community of breeding birds that reach high abundances in comparison to managed vineyards, within an otherwise impoverished agricultural landscape.