An index of ecological value for European arable plant communities

The value of arable plant communities from a natural and environmental perspective was recognized only recently. Human-dependent arable plant assemblages are acknowledged to support biodiversity in agroecosystems and to provide numerous ecosystem services. The conservation of such communities relies on low-input, traditional agriculture, which is vanishing worldwide. Both agricultural intensification and land abandonment negatively affected arable plant biodiversity, with a remarkable loss of species and communities of great conservation and ecological interest. In this paper, we introduce a floristic-ecological monitoring tool aiming at the quantification of the ecological value of arable plant communities, named ArEco. Starting from presence-absence community data, the index returns a numerical value derived from species richness and six features of arable vascular plants: life form, Ellenberg nutrient value, alien status, conservation status in Europe, support to pollinator insects, and support to feeding birds. A program for the calculations was written in Java, with a database of about 400 arable plant species. The effectiveness of the tool was tested on 270 arable vegetation plots of different crop types in Italy, a European hotspot of arable plant diversity. The results show that, in the study area, winter arable vegetation has a higher ecological value than summer arable vegetation. In a similar way, extensively managed arable land hosts communities of higher ecological value than those hosted by intensively managed arable land. In view of the present results, ArEco will be a useful tool for monitoring, conservation, and restoration activities of arable plant communities in Europe.