Habitat audit introduction

The Audit was conducted using best available data. The starting point for most of the habitat audits was the survey carried out under contract to the Greater London Council by the London Wildlife Trust in 1984 and 1985. This is currently held by the London Ecology Unit and continuously updated. The survey was augmented by subsequent re-surveys of boroughs, information on habitats held by English Nature, and information obtained directly from site managers, local authorities and private land-owners. Each individual habitat/land use audit is referenced to identify the data sources.

The quality of the data varies between habitats. The most comprehensive individual audit is that of London's woodlands. Limited time and resources did not allow as comprehensive an audit for other habitats. In some cases there is a mismatch between the definition applied to the habitat for field survey and the definition applied to the habitat category for the London Biodiversity Audit. This has undoubtedly resulted in double accounting, or other errors in calculating the areas of habitat for the Audit. A 'Rationale and Limitations' section is provided for each individual habitat/land use in an attempt to highlight potential errors.

Despite these qualifications, the Partnership believes that the figures provided for each habitat and land use provide a reliable assessment of the extent of habitats at a London level. The figures provided for individual boroughs are more likely to encompass a wider margin of error.

In order to facilitate and encourage discussion between key partners, the individual habitat audits include sections on 'Nature Conservation Importance' and 'Threats and Opportunities'.

'Nature Conservation Importance' identifies the reasons why the habitat or land use is important for the conservation of biodiversity. This section identifies some of the key attributes of the habitat or land use and some of the species that have a particular association with it. The species used to illustrate the habitat or land use are those that have been listed in the Species Audits. Only a representative group of characteristic and habitat-specific species have been noted in the Habitat Audits. The intention is to illustrate the range of which species might be encountered - from the rare to the common and from the obscure to the familiar.

'Threats and Opportunities' identifies some of the generic problems and solutions for biodiversity conservation in specific habitats. Not all potential problems and solutions are listed; some are very site-specific issues that are best identified within borough Biodiversity Action Plans or corporate Biodiversity Action Plans prepared by individual partners.

The Habitat Audits are not definitive. It is intended that the publication of the data will elicit further information and critical comment that will inform future reviews of this audit and the next stage of the biodiversity action planning process.