The contribution of arable weeds to biodiversity.

Abstract

There is increasing recognition in Europe that arable plants have functions beyond simply suppressing the yield of crops. The function best quantified to date is the support they provide to higher trophic groups and to the whole food web of farmland. This food web mediates essential ecological processes such as the element cycles and pollination, and contributes aesthetic qualities through butterflies, birds, rare plants and landscape. The food web has been seriously diminished in the last half-century to the extent that it is now much less than 1% of the total summer biomass in intense arable systems. This paper summarises the evidence for the importance of arable plants to higher trophic groups and discusses the means to regenerate them with least detriment to crop yield. It shows that the field margins and the cultivated area sown with crops have their distinct contributions and should be managed integratively.