4. BIODIVERSITY STATE INDICATORS
S1. STATUS OF UKBAP PRIORITY SPECIES
Red squirrel
Sciurus vulgaris
Biodiversity Action Plans ( BAPs) have been prepared for habitats and species considered threatened within the UK. They include 153 'priority' species occurring, or known to have occurred, in Scotland until recently. The species are taxonomically and ecologically diverse, and are likely to be sensitive to change in the ecosystems and natural processes on which they depend. They therefore provide indicators of change in terrestrial, freshwater and marine environments. Trends across the suite of BAP priority species, as reported here, indicate progress towards halting biodiversity loss. The first comprehensive assessment was in 2005. Trends will be reported through the (three-yearly) UKBAP reporting cycle.
SCOTTISH TREND FOR BAP PRIORITY SPECIES
The status of BAP priority species in Scotland reported in the 2005 assessment (grouped plans excluded)
TREND: BASELINE | DATA CONFIDENCE: SATISFACTORY |
EVIDENCE
The web-based Biodiversity Action Reporting System ( BARS) is a central data repository that enables integrated national and local reporting on BAP species. Assessments for BARS are made by Lead Partners, who report on BAP species according to their specialist expertise and the data available.
ASSESSMENT
- 11 species (7%) were increasing/fluctuating probably increasing
- 49 species (32%) were stable/fluctuating probably stable
- 27 species (18%) were declining (in 3 status categories)
- 17 species (11%) showed no clear trend and the trend for 44 (29%) was unknown
- 2 species (1%) were thought to be no longer present in Scotland and 3 (2%) were no longer considered to be true species
COMMENTARY
BAP Priority Species are the focus of concerted conservation action through Species Action Plans. Species that increased included the corncrake Crex crex (a migratory bird whose range in Scotland has contracted to the western fringes) and vendace Coregonus albula (a re-introduced non-migratory fish, considered to be the UK's rarest freshwater fish). Species that remained stable included the great yellow bumblebee Bombus distinguendus. This bee is associated with extensive areas of heb-rich grasslands, formerly distributed throughout Britain, but is now restricted largely to the machair grasslands of northern and western Scotland. Species that declined included the rare twinflower Linnaea borealis, found primarily in native pinewoods, and common skate Raja batis, the largest of the skate and ray species present in European waters, and declining primarily due to fishing pressure.
Improved monitoring was available for the 2005 assessment, but appreciable gaps in knowledge of priority species outside protected areas need to be addressed.
Habitat destruction and degradation (particularly through agriculture and infrastructure development), and climate change, are reported to be the current or emerging threats of greatest significance.
DATA UPDATES
Biodiversity Action Reporting System ( BARS). Although Lead Partners reported in 2002, the 2005 assessment was more comprehensive. Updates will become available in a three-year BAP reporting cycle. The UKBAP covers 380 Species Action Plans, plus 11 Grouped-Species Action Plans for a further 95 species. Grouped plans were reported in 2005 for the first time.
The next assessment will be in 2008.
UK INDICATORS
The UK and Scottish indicators are both derived from the Joint Nature Conservation Committee ( JNCC) survey of BAP Lead Partners, so are broadly comparable, although the number of species used for the UK indicator is greater. For species where status is known, the UK indicator (Defra, 2007) shows a similar overall trend to the Scottish indicator.
REFERENCES