Accounting for Nature: Assessing habitats in the UK countryside
4.   Boundary and Linear Features

Conclusions

4.39 For the Boundary and Linear Features Broad Habitat the most significant finding of CS2000 is that the declines in length of hedges and walls reported for the 1980s have been halted, and in the case of hedges in England and Wales, there is some evidence that losses in the early 1990s have been reversed. This has been achieved by a shift in balance between hedge removal and planting, hedge restoration and damage, and wall removal and re-construction.

4.40 Comparison with the 1984-90 period in England and Wales shows that rates of hedge planting are similar but rates of removal have fallen markedly. There is evidence for a gradual degeneration of woody linear features as some hedges degenerate to remnant hedges and some of these in turn degenerate to lines of trees or shrubs. But, unlike the 1980s and early 1990s, restoration and management has largely counteracted these trends. These changes coincide with the general downturn in the agricultural economy during the mid-1990s and the increased incentives, advice and regulation over this period. However, the large turnover has implications for the quality of the resource. The issue that is now apparent is one of maintaining this balance by promoting good management, as well as the protection of the most important of these features. The Hedgerow Regulations introduced in 1997 and recent expansion of agri-environment schemes are already addressing this issue.

4.41 There is some evidence, however for a decline in aspects of the quality of the Broad Habitat. The vegetation of some hedges and roadside verges has become less diverse and more dominated by tall, competitive plants, associated with increasing nutrient status. These changes are an issue especially in the intensively farmed landscapes of England and Wales, where linear features serve as important refuges for biodiversity. The reasons for these changes require more detailed investigation.

4.42 The preliminary analysis presented here has not considered the relationships between management and substitution of linear features, adjacent land use, connectivity and ecological condition, including woody species diversity in hedges. Nor have the implications of changes to the local landscape character been addressed. These are topics for future work.