Indicator assessment
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 yet
available for this extended list.
For many habitats, status assessments are not
available in all recording years. To make best use of available
data and because the change in status is assessed by comparing, for
each habitat, the earliest available assessment with the most
recent. The majority of the earliest assessments (72%) are from
1999 or 2002. The majority of the most recent assessments (81%)
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 3%, the indicator is assessed as showing little or no
change.
Description of trends
The indicator shows a very small net decrease
in the number of habitats that are stable or increasing and 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 7 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 recording years
(2002, 2005 and 2008 – 1999 being a year with poor 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 9 to 8, followed by an increase to 10 habitats in
2008.
Figure 4 (iii) Changes in the status of the UK 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 Action Plan contained
a set of plans for 45 priority habitats. The Plan was revised in
2007 and the number of priority habitats increased to 65, although
assessments are not yet available for this extended list. 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. The indicator is based on the
periodic status assessment, rather than on progress to targets.
Background
Status assessments for UK Biodiversity Action
Plans priority species were undertaken in 1999, 2002, 2005 and
2008. Assessments are undertaken by various 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.