Indicator description
The indicator shows the change in the status of 45 priority
habitats assessed between 1999 and 2008. Every three years, the
status of priority habitat has been assessed by a range of experts
across the UK. The indicator assessment is based on the change in
the status of the 43 habitats for which a status assessment is
available in at least one of the recording years.
The Plan was revised in 2007 and the number of priority habitats
increased to 65, but assessments are not available for this
extended list.
For many habitats, status assessments are not available in all
recording years. To make best use of available data, the change in
status for each habitat is assessed by comparing the earliest
available assessment with the most recent. The majority of the
earliest assessments (72 per cent) are from 1999 or 2002. The
majority of the most recent assessments (81 per cent) were made in
2008.
Of the 43 habitats in the indicator, the number that were
assessed as either ‘stable’ or ‘increasing’ in area has fallen from
21 to 20. Given that this is a fall of less than three per cent,
the indicator is assessed as showing little or no change.
There has been a limited amount of turnover of habitats over the
period 1999–2008. Lowland beech and yew woodland habitats were
recorded as decreasing in 2002 and increasing in 2008. Lowland
calcareous grassland and upland calcareous grassland were both
stable in 2002 but decreasing in 2008. There has also been a
change in the number of habitats reported as ‘unknown’ from 11
habitats in 2005 to six in 2008. The number of habitats reported as
‘increasing’ fell from 10 in 2005 to seven in 2008, although
one of these habitats was reported as unknown in 2008, and one
habitat was not reported and was therefore categorised as unknown
(see Table 4 (i)).
Table 4 (i) Number of habitats reported in each category in
2005 and in 2008
|
Habitat trend
|
2005
|
2008
|
|
Increasing
|
10
|
22.2%
|
7
|
16.0%
|
|
Declining
|
17
|
37.7%
|
19
|
42.2%
|
|
No clear trend
|
1
|
2.2%
|
4
|
8.9%
|
|
Stable
|
6
|
13.3%
|
9
|
20.0%
|
|
Unknown
|
11
|
24.4%
|
6
|
13.0%
|
|
Grand Total
|
45
|
100%
|
38
|
100%
|
There are 21 habitats for which there is a status assessment
available in three consecutive reports (2002, 2005 and 2008; 1999
was a year with few returns). Figure 4 (iii) shows the change in
status for these 21 habitats. The figure shows a similar pattern of
little or no overall change in the pattern of assessments, although
it does show a fall in the number of habitats that are ‘stable’ or
‘increasing’ between 2002 and 2005, from nine to eight,
followed by an increase to 10 habitats in 2008.
Figure 4 (iii). Changes in the status of the UK BAP priority
habitats, for 21 habitats that have been assessed in all recording
years 2002–2008
Relevance
The UK Biodiversity Action Plan (BAP) is the UK’s national
biodiversity strategy, prepared in response to the UN Convention on
Biological Diversity (CBD). The Priority Habitats are natural and
semi-natural habitats of high nature conservation value. The
targets set out in the habitat action plans reflect the desire to
maintain or extend their area and represent the shared goals of the
UK Government, its Statutory Agencies and the voluntary sector, but
the indicator is based on the periodic status assessment, rather
than on progress against detailed targets.
Background
Status assessments for UK Biodiversity Action Plans priority
habitats were undertaken in 1999, 2002, 2005 and 2008. Assessments
are undertaken by a variety of conservation agencies, taking
account of any available biological monitoring or surveillance
data. The amount and currency of data varies from habitat to
habitat – some are based on comprehensive inventories, some on
expert opinion. The indicator takes the assessments at face
value.
The first assessment (in 1999) took place very soon after many
of the plans were published and comparatively few assessments were
made. The indicator therefore compares the earliest available
status assessment (i.e. 1999 if it is available, 2002 if it is not,
2005 if neither 1999 or 2002 are available) against the latest
(2008, if available, 2005 if not and so on).
As can be seen from Figure 4 (ii), the categories used in 2008
(and in each of the previous three assessments) were more detailed
than the three categories used in the indicator. This is because
different assessment categories were used in the four years and
they have been compiled to allow easier comparison across years
(Table 4 (ii)).
Table 4 (ii). Consolidation of status assessment categories for
presentation in the indicator
|
Categories used in the indicator
|
Categories used in the original assessments
|
|
Increasing
|
Fluctuating - probably increasing
Signs of recovery
Increasing
|
|
Stable
|
Fluctuating - probably stable
No change
Stable
|
|
Decreasing
|
Declining (continuing/accelerating)
Declining (slowing)
Fluctuating - probably declining
No data entered
|
|
Unknown
|
Insufficient information
Fluctuating / No clear trend
No clear trend
No data entered
Unknown
|
The 2009 presentation is a refinement of the indicator published
in 2007 which presents data for 16 habitats from 2002 and 2005
only. A technical background paper is available and provides a more
detailed description of the method (see attachments below).
Further development planned
The UK BAP priority species and habitats have been reviewed
and the new UK List of priority species and habitats was
published in August 2007. Future reporting needs for the new list
of species and habitats are still to be determined.