Hedgerows Habitat Statement - page 1
Definition
Hedgerows are linear features composed of woody species. Ancient hedgerows are those which were in existence before the Enclosures Acts (passed between 1720 and 1840 in Britain). Species-rich hedgerows are those which contain 5 or more native woody species on average in a 30 m length, as defined in Wicks & Cloughley, 1998.
In urban areas many hedgerows are of relatively recent origin, having been planted along the boundaries of gardens, parks or open space around schools and other institutions. These hedgerows are frequently composed of non-native coniferous or evergreen species.
London’s hedgerow resource
The 1984/5 London Wildlife Habitat Survey documented native-species hedgerows only where these were within survey parcels. Therefore native-species hedgerows which fell outside survey parcels, such as those hedgerows traversing areas of arable farmland or close-mown amenity grassland; or isolated within the urban fabric, were not documented. This restricted data resulted in only 369 ha of native-species hedgerow being identified in London. This is undoubtedly a serious underestimate. However, when the amount of documented native-species hedgerow is identified by borough, as a percentage of the total native-species hedgerow resource in London, it does give an indication of the distribution of this resource (Table 1 - data taken From London Wildlife Habitat Survey 1984/85). Unsurprisingly, the bulk of this habitat is found in those outer London boroughs with extensive areas of countryside.
Other studies have been undertaken in an attempt to estimate the native-species hedgerow resource in London. A study by Vickers for the London Biodiversity Partnership estimated a total native-species hedgerow resource of 705 km. A study undertaken to estimate the extent of rural hedgerows in the London Borough of Brent found 31km.
None of the above studies have taken into account the extent of non-native hedgerows which, although of less intrinsic nature conservation value, are likely to account for most of the hedgerow resource in London.
Table 1: Native-species hedgerows in Greater London
|
Borough |
Percentage of London’s resource (%) |
Borough |
Percentage of London’s resource (%) |
|
City of London |
0 |
Hillingdon |
14.2 |
|
City of Westminster |
0 |
Hounslow |
4.2 |
|
Barking & Dagenham |
0.3 |
Islington |
0 |
|
Barnet |
17.8 |
Kensington & Chelsea |
0 |
|
Bexley |
0.9 |
Kingston |
1.5 |
|
Brent |
0.9 |
Lambeth |
0 |
|
Bromley |
10.8 |
Lewisham |
0 |
|
Camden |
0 |
Merton |
0 |
|
Croydon |
1.7 |
Newham |
0.1 |
|
Ealing |
2.1 |
Redbridge |
1.9 |
|
Enfield |
3.3 |
Richmond |
0.4 |
|
Greenwich |
1.1 |
Southwark |
0.8 |
|
Hackney |
0 |
Sutton |
0.4 |
|
Hammersmith & Fulham |
0 |
Tower Hamlets |
0 |
|
Haringey |
0.6 |
Waltham Forest |
0.1 |
|
Harrow |
4.7 |
Wandsworth |
0 |
|
Havering |
32.3 |