ABSTRACT
The Allerton Project research and demonstration farm in Leicestershire (UK) has studied field margin management with a particular focus on birds and invertebrates. Some bird species show a direct response to the amount of herbaceous vegetation in field margins, and the structure of woody vegetation influences nest survival rates. Dams in ditches hold back water in summer, increasing invertebrate biomass, and provide other biodiversity benefits. Creation of seed-bearing agri-environment mixtures in field margins increases the winter food availability to farmland birds.
The abundance of crop pest predators is affected by herbaceous vegetation structure, tall vegetation benefiting web-building spiders, and dense tussocky grasses providing overwintering habitat for carabid and staphylinid beetles. The community structure of beetles in hedges and woodland edges differs. A small number of common, naturally occurring, plants provide foraging resources for pollinating insects, but establishing diverse mixtures of flowering plants extends the period in which this resource is available. The fruit-set of some common shrubs is limited by pollinator abundance, in turn influencing the abundance of winter food for birds.
Habitat, species, and structural diversity within field margin vegetation therefore influence bird and invertebrate species abundance and diversity. This information can be used to guide field margin management to deliver multiple benefits at a range of scales.
