UK habitat surveillance results summary

The overall rate of change of area and distribution of semi-natural habitats appears to be decreasing and some surveillance schemes suggest that the area of certain habitats - such as broadleaf woodland – is stabilising or increasing. However this signal masks reductions in overall quality (as measured by, for example, plant diversity and habitat structure) or more subtle changes between habitat types.

Countryside Survey and the Land Cover Map give comparable measures of distribution and extent of all terrestrial habitats at a UK level at a course (broad habitat) level, and this is amplified by a few habitat-specific initiatives such as the National Inventory of Woodland and Trees. However finer grain surveillance is needed to understand the changes within broad habitats and link these to the pressures acting on them. This is available to a limited degree for some broad habitats through initiatives such as the long-term monitoring of ecological changes in British woodlands and sample surveys of non-statutory BAP Priority grassland and heathland sites in England.

Pressure	Key messages from UK habitat surveillance and monitoring
Over-exploitation	Over-exploitation is not a major issue for most UK habitats, with the exception of grazing pressure. In the uplands overgrazing continues to cause both declines in quality and loss of habitats (such as increased bracken domination on moorland) - although in some cases this signal can be difficult to separate from other pressures such as eutrophication – and considerable turnover. Lack of management including recent declines in grazing is a more pertinent issue for some habitats (e.g. grasslands, heathlands), particularly in the lowlands. Key schemes: Countryside Survey; Common Standards Monitoring
Pollution	Eutrophication, particularly from nitrogen deposition, has replaced acidification is the major current pollution impact, and is increasingly implicated as a major cause of habitat change as evidenced through floristic and soil changes. In the uplands there is a strong interplay between the eutrophication signal and over-grazing, whilst agricultural improvement drives eutrophication in grasslands. Habitats with less natural buffering capacity, such as dwarf shrub heaths, show the strongest eutrophication signal. Countryside Survey provides some evidence on eutrophication which is supported by initiative such as BSBI atlases, the BSBI Local Change network and the Common Plants Survey. JNCC, Defra and other partners are investigating the feasibility of a new network for measuring the impacts of air pollution. Key schemes: Countryside Survey, BSBI atlases, BSBI local change, Common Plants Survey (Plantlife)
Habitat loss	UK level surveillance suggests that the rate of direct habitat loss in the UK slowed during the 1990s as grazing issues and eutrophication became more important. However reporting information from the BAP process suggests that the loss of semi-natural habitats, particularly priority habitats, is still occurring. In the unenclosed uplands, grazing and eutrophication pressures continue to cause significant habitat change and loss, a finding supported by CSM results. Key schemes: Countryside Survey, Land Cover Map.