The Phase 1 Habitat
Classification and associated field survey technique provide a
standardised system to record semi-natural vegetation and other
wildlife habitats. The approach is designed to cover large areas of
countryside relatively rapidly. It presents the user with a basic
assessment of habitat type and potential importance for nature
conservation. Each habitat type/feature is identified by way of a
brief description of its defining features. It is then allocated a
specific name, an alpha-numeric code, and unique mapping
Early work on the Phase 1
survey technique dates back to the 1970s. This was developed
further in the 1980s and in 1990 an A4 Phase 1 Handbook and
supporting A5 Phase 1 Field Manual
were published by the Nature Conservancy Council (NCC). Later
versions of these publications (with limited additions) have been
produced by JNCC (see below).
Since its creation, the
Phase 1 technique has been used widely. Many county-wide surveys
have been completed, along with many other more localised mapping
projects (see Wyatt 1991). The Phase 1 Habitat Survey of Wales,
which was completed in 1997 by the Countryside Council of Wales,
provides coverage of the whole of Wales (Howe et al.
2005). The approach is a commonly used standard in the preparation
of environmental impact statements and other ecological baseline
surveys. It is also useful in identifying Open Country under the
The Countryside and Rights of Way Act 2000.
Details of the Phase 1
The Phase 1 classification
comprises ten (A-J) broad high level categories:
A: Woodland and
B: Grassland and
C: Tall herb and fen
F: Swamp, marginal and
G: Open water
I: Exposure and
Amongst these, 155 specific habitat types are recognised, each
having its own name, alpha-numeric code, description and mapping
colour. A spreadsheet containing all the Phase 1 habitat names and
codes is available via the following download: Phase 1 codes for habitats &
dominant species. This spreadsheet also contains the Phase 1
codes for dominant species and shows the additional habitat
categories created for the Phase 1 Habitat Survey of
Wales (NB: the latter have NOT been formally incorporated into
the JNCC Phase 1 classification).
Descriptions of each of the Phase 1
habitats are available in the JNCC A4 Phase 1 Handbook or
A5 Phase 1 Field Manual.
Correspondence with other
An interactive spreadsheet containing the
correspondences between Phase 1 types and those identified in other
mainstream vegetation/habitat classification systems is available
via the following download: NBN
dictionary habitat correspondances.
GIS (including Phase 1 colour
ArcGIS 'style file' containing the Phase
1 colour mapping palette is available via the following
Phase 1 mapping
This file can be extracted
and applied to ArcGIS shapefiles (polygons, lines and points),
using ArcGIS version 8.x or later. The download
(i) a README.doc file
(explaining how to extract and install the palette);
(ii) the Phase 1 ArcGIS
palette style file;
(iii) a PDF legend showing
the whole palette on a single page;
(iv) an Excel spreadsheet
containing the RGB (Red-Green-Blue) values for each colour used in
the palette (this should allow users to create the same palette in
GIS users, a Phase1 habitat survey 'keysheet
package' is available from the
RSK website. This includes examples of its application and a
key in PDF format. The website has instructions on its use and a
contact for feedback.
BosqMap Ltd have also produced a
MapInfo add-on tool for producing Phase 1 habitat maps. MapInfo
fill pallet, line styles and symbols have been customised to match
the styles in the Phase 1 Handbook. The software works on all
MapInfo versions from 8.0 onwards. Click
here for further details and to request a trial download.
SNH Information and Advisory Note Number 62 provides advice on
handling Phase 1 habitat survey data within a GIS environment.
JNCC Phase 1
There are two JNCC Phase 1
publications, which have been reprinted several times with limited
revisions and additions (see below). There has, however, been no
change made to the Phase 1 habitat types or the colour palette
since its publication in 1990.
A4 Phase 1 Handbook: this
was published first in 1990, reprinted in 1993, reprinted again in
2003 with limited revisions & additions, reprinted again in
2004, reprinted agian in 2007 with minor additions, and reprinted
last in 2010 with minor revisions.
Note that no changes have
been made to the Phase 1 classification itself, including the
alpha-numeric coding scheme, habitat descriptions, and colour
mapping scheme, since it was published in 1990
A5 Phase 1 Field Manual:
this was published first in 1990, reprinted in 1993, reprinted
again in 2003 with limited revisions and additions, and reprinted
last in 2005.
It is now available only as
Part 2 of the A4 Phase 1 Handbook.
List of other Phase 1 related
Blackstock, T.H., Burrows,
C.R., Howe, E.A., Stevens, D.P. and Stevens, J.P. 2007. Habitat
inventory at a regional scale: a comparison of estimates of
terrestrial Broad Habitat cover from stratified sample field survey
and full census field survey for Wales, U.K. Journal of
Environmental Management Volume 85, pages 224-231.
Blackstock, T.H., Stevens,
J.P., Howe, E.A. and Stevens, D.P. 1995. Changes in the extent and
fragmentation of heathland and other semi-natural habitats between
1920-22 and 1987-88 in the Llŷn Peninsula, Wales, UK. Biological
Conservation Volume 72, pages 33-44.
Cherrill, A.J. and McClean,
C. 1999. Between observer variation in the application of a
standard method of habitat mapping by environmental consultants in
the UK. Journal of Applied Ecology Volume 36, pages 989-1008
Cherrill, A.J. and McClean,
C. 1999. The reliability of Phase 1 habitat mapping in the UK: the
extent and types of observer bias. Landscape and Urban Planning
Volume 45, pages 131-143.
Dargie, T. 1993. Repeat
Phase 1 habitat survey and detection of vegetation
change. English Nature Research Reports 51. English Nature,
Howe, L., Blackstock, T.,
Burrows, C. and Stevens, J. 2005. The Habitat Survey of Wales.
British Wildlife Volume 16, pages 153-162.
Stevens, J.P., Blackstock,
T.H., Howe, E.A. and Stevens, D.P. 2004. Repeatability of Phase 1
habitat survey. Journal of Environmental Management, Volume 73,
Wyatt, G. 1991. A Review of
Phase 1 Habitat Survey in England. England Field Unit, Nature
Yeo, M.J.M. and Blackstock,
T.H. 2002. A vegetation analysis of the pastoral landscapes of
upland Wales, UK. Journal of Vegetation Science Volume 13, pages