The potential for native woodland in Scotland:
the native woodland model Management

Natural Heritage Management

• Executive Summary
• Introduction
• Assumptions and general principles underlying the Native Woodland Model
• The value of modelling potential woodland cover
• Methodology
• How accurate is the NWM?
• How potential woodland types correspond to HAP types
• Use of the Native Woodland Model – case studies
• References
• Appendix 1 The base datasets
• Appendix 2 The National Vegetation Classification
• Appendix 3 Allocation of woodland types to different site conditions
• Appendix 4 Correspondence between NWM and HAP types

Appendix 1: the base datasets

The 1: 250 000 scale national soil map

This map comprises 580 soil map units, differentiated on geological (soil association), pedological (component soils) and physiographic criteria (landforms).

The map is underpinned by an extensive database from which information on soil (and vegetation) properties important for the growth of different woodland types, such as base status, nutrient status and moisture regime, can be readily inferred. The system of soil classification and the terms used in soil description can be found in the handbook which accompanies the map series (MISR 1984).

Information of particular relevance to the definition of woodland suitability includes: (a) parent material and base status of different soils, (b) soil nutrient status, moisture regime and depth, and (c) landform features such as slope, rockiness or morainic deposits, which influence the proportions of different soil types within complex and heterogeneous landscapes.

The 1:25 000 Land Cover map

This map provides information on Scotland’s land cover as it was in 1988 and was captured from the visual interpretation of aerial photographs. The hierarchical classification allows for 126 single land cover features including all the major semi-natural vegetation communities. There are also over 1000 mosaic categories used largely to describe the heterogeneous semi-natural vegetation resource.