S7 Woodland Diversity Indicator
Ariundle National Nature Reserve
Table 1: Components of the Woodland Diversity Indicator (1995-99 baseline)
Data for whole woodland resource, including semi-natural woodland and plantations.
Mean shrub layer cover (%) (1) | 17 |
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Mean number of trees and shrubs species (per 0.25 ha) (2) | 2.2 |
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Mean volume of deadwood (m 3 per ha) (3) | 4.4 |
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Percentage of total woodland in old-growth stage (%) (4) | 4.8 |
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(1) Only for sampling areas with an upper canopy (>15m high).
(2) Includes native and non-native species. This figure cannot be used to estimate species numbers at other sizes of sampling unit (i.e. 1 ha)
(3) Includes fallen and standing timber.
(4) Cut off year for defining old-growth: conifers - 1901; broadleaves - 1861.
TREND: BASELINE | DATA CONFIDENCE: SATISFACTORY |
The Scottish Biodiversity and Forestry Strategies set out objectives for the protection and enhancement of priority habitats associated with woodland, and for the conservation of priority species such as Red Squirrel Sciurus vulgaris and Capercaillie Tetrao urogallus. Attributes of woodland structure and composition such as the number of canopy layers or types of trees and shrubs are known to relate closely to species and habitat diversity.
Assessment
- No trend is available yet as the data shown are baselines generated from the first National Inventory of Woodland and Trees ( NIWT).
- Favourable trends in the indicator would be reflected by general increases in the values for all four components over time.
Evidence
The Indicator includes key components of woodland structure and composition: vertical foliage cover (shrub layer); tree/shrub species composition; deadwood and stand growth stage. The data were collected as part of the NIWT between 1995 and 1999.