Restore little to improve much. The value of woody linear elements for ecological connectivity across agricultural landscapes

Mediterranean Europe is facing significant pressures from agricultural intensification. The European Union (EU) Natura2000 network (N2K) seeks to mitigate habitat loss and fragmentation, but its effectiveness needs to be enhanced through Green Infrastructure (GI) to improve coherence between N2K patches. The present research applies a GI design procedure at the local level for persistence and dispersal of species that are characteristic of Potential Natural Vegetation (PNV), based on the conservation/restoration of woody linear elements (LE) among N2K patches scattered in agricultural landscapes. The procedure was tested in the western sector of the City of Rome, Italy, through: (1) identification and classification of relevant GI components in the current landscape mosaic, (2) measurement of N2K network coherence (i.e. structural connectivity) and modeling/refinement of the optimal path for improving the support to PNV-characteristic species, (3) assessment of LE conditions in terms of biodiversity-support capacity to define pertinent conservation/restoration actions, and (4) quantification of potential GI benefits in terms of N2K network coherence and landscape functionality gains. Besides LE to be planted, conservation actions were defined for occurring LE in favorable conditions, while restoration actions were defined for LE in adequate and unfavorable conditions, including improvement in tree and shrub composition and removal and conversion of non-native species, respectively. Despite a little area to be restored, GI actions nearly doubled the original network coherence and substantially increase landscape functionality, while supporting biodiversity under a land-sharing perspective. By minimizing conflicts with primary production, the design approach can facilitate achievement of EU agroecosystem restoration targets.