10: Native Woodland Condition indicator

What information does the survey provide and why does it matter?

A simple baseline measure from the survey of native woodland condition for biodiversity is helpful for national and regional reporting in relation to the UK Biodiversity Action Plan (UKBAP). UKBAP targets are for increases in the area of each priority woodland type that is in good condition. Prior to Native Woodland Survey of Scotland there have been no consistent data on extent or condition of native woodlands of any type in Scotland. 

A native woodland condition indicator has been developed by testing a range of measures from the survey. This has identified the most useful factors that are relevant to every unit area of native woodland, and can indicate ecological health/condition no matter what the age or type of native woodland.

Four factors have been chosen which are critical in influencing biodiversity values and woodland sustainability, and are similar to measures typically used in site condition monitoring for designated woodland features. The four attributes are:

  • canopy cover (50-90%)
  • percentage of canopy comprising native species (at least 90%)
  • herbivore impact (A or B)
  • invasive non-native species (no more than 10% cover and less than three invasive species present)

The indicator is calculated by assessing how much of the area in the region has 0,1,2,3, or 4 attributes in the desired range (shown in brackets above). This is useful at national and regional level to indicate the proportion of the area of each priority type that is in good health or condition for biodiversity and to suggest key issues for focusing policy or incentives where intervention is needed.

The indicator could be a basis for reporting progress against native woodland condition targets under the UK Biodiversity Action Plan, where the target could be expressed in terms of proportion of area with all 4 attributes in the desired range.

However a generic condition indicator such as this is not suitable for site assessment, because each site is different and the context and character and objectives of management of each site needs to be taken into account. For this reason, the indicator values are not reported at polygon level.

Policy relevance

UKBAP targets for maintaining and improving condition have been incorporated into Scottish Forestry Strategy and Scottish Biodiversity Strategy programmes. UKBAP targets are monitored and reported every 3 years.

How can the NWSS data be used?

Type of use National  Regional/local authority Landscape/site scale 
Reporting area in good condition for each priority woodland type  Yes Yes n/a
Identifying key condition weaknesses to be addressed Yes Yes n/a