Additional sampling of hedgerows and field margins within the farmed landscape.

Arable Field Margins
The importance of the arable ecosystem for the biodiversity of the wider countryside is becoming increasingly apparent. The arable flora remains the most threatened group of plants in Great Britain, but still persists in small, isolated pockets within field margins. The traditional broad-leaved plant flora of cereal fields and their margins is giving way to one more dominated by grasses, and there are now many fields which are virtually weed-free. While this may not be of wide conservation concern in itself, this is one of the factors which is thought to be contributing to the decline of the animal groups which depend on them, in particular arable birds.

The arable field margin has been recognised in present policy. In particular, there is a costed habitat plan for field margins within the Biodiversity Action Plan, and the Arable Incentive Scheme (a pilot programme within the Countryside Stewardship Scheme) has been designed to help deliver the action plan. It is recognised that the Scheme should be targeted at farms which are likely to have the basis for quality arable ecosystems.

CS2000 provided an important opportunity to survey this habitat, allowing for the analysis of its present condition and for monitoring the delivery of the cereal field margin Biodiversity Action Plan. A 100 x 1 m strip of margin in all arable fields was surveyed as part of CS2000.

Hedgerows
Ancient and species-rich hedgerows are considered to be particularly important features of the countryside in terms of biodiversity. Ancient hedgerows may be defined as those which were in existence before the Enclosures Acts (c. 1720 - 1840) and species-rich hedges are taken as those that contain five or more woody species, or four in more northern and upland areas, per 30 metre length.

Hedgerow protection regulations were introduced in England and Wales with the aim of preventing the removal of hedgerows important for wildlife, landscape and heritage.  As part of the UK Biodiversity Action Plan, DEFRA are leading a habitat action plan for ancient and/or species-rich hedgerows.

Countryside Survey 2000 recorded information on hedgerows and hedgerow trees. The DEFRA funded project enhanced the Countryside Survey 2000 database by recording additional information on the woody species component of the hedgerow and also allowed a full analysis of hedgerow trees and changes in these since previous survey dates (1984 and 1990). This has enabled monitoring of hedgerows as specified in the Biodiversity Action Plan.