The habitat survey map is an important step in the development of your woodland grazing plan. It should give enough information to complete columns 1 to 2 of Tables 3a and 3b in your plan.
Gathering and presenting the information
You will need to:
- map both woodland and open ground habitats
- decide which of these are key habitats
- if possible, identify the location of key features
You may have some of this information already, in the form of past surveys of Native Woodland Condition, Phase 1 habitats or National Vegetation Classification (NVC) communities. Some habitat information will be available in the Native Woodland Survey of Scotland.
It is unlikely that your habitat map can be based entirely on these existing surveys; additional information will be needed to create a map that provides the necessary habitat information.
Habitats should be identified and mapped to take account of your overall management objectives, whilst providing the appropriate level of detail for an assessment of herbivore impacts and an assessment of forage potential - without making the exercise unnecessarily complicated.
An Ordnance Survey map at a scale of 1:10,000 is likely to be an ideal base map for showing your survey information. Do not use a map that has a smaller scale (e.g. 1:25,000). Make sure you include:
- the name of the wood
- the date
- a key to the information shown
- the map scale and an OS grid reference
The habitat survey map should show the extent and distribution of woodland site types present in your woodland. Depending on your woodland objectives you may need to subdivide the site types in order to show different NVC communities or BAP priority habitats.
Refer to the comparison table to determine the relationship between these three ways of defining woodland areas.
If it is easier, or more informative, call a habitat by its BAP habitat name or NVC category, e.g. ‘upland oakwood’ or ‘W17 oak woodland’ rather than the woodland site type label ‘acid dry woodland’.
Mappable areas of established regeneration (areas where there are saplings over 50 centimetres in height at a stocking density of approximately 1100 stems per hectare or more) should be mapped and recorded separately.
Areas that do not fit the definition of established regeneration but where there are frequent seedlings should be included in the relevant open ground category. Make a note of these potential regeneration areas on the habitat map and in section 3b of your woodland grazing plan.
Areas of young trees too advanced to be checked by browsing animals, e.g. 'pole-stage' trees, should be included in the appropriate woodland site type category.
Open ground habitats and conifer plantation
Map areas of open ground habitat or conifer plantation. There may be a mix of more than one non-wooded habitat type within a relatively small area. Mosaics of open ground habitats will need to be mapped as such, with the proportion of each recorded in the map key and in section 3b of your woodland grazing plan.
Recording proportions is especially important where there are habitats in the mosaic with significantly different forage productivity, e.g. bracken and neutral grassland.
Mapping a complex woodland structure
Management objectives may require you to sub-divide a woodland type, e.g. dry acid woodland may need to be divided into, say, ‘dry acid - upland oak woodland’ and ‘dry acid -upland birchwood’, and so on. Or management objectives may require you to subdivide a woodland site type into different structural components, e.g. moribund oak woodland might need to be mapped separately from oak woodland with a range of younger age classes.
However, a woodland where controlled livestock grazing is appropriate is likely to have a complex structure where some simplification is necessary. It is probable that you will need to limit the number of habitats recorded on the map and in section 3 of your plan.
There may be two or more physically separate areas of the same habitat, e.g. there may be more than one stand of the dry acid woodland type, not physically connected but having characteristics in common that allow you to record and assess them as one habitat.
If there is an intimate mix of habitats, you will need to map and record the mix as a mosaic, estimating and noting the proportions of each major component. Very small areas can be left off the map but If they have a significantly different forage potential to the major components (for example, if the habitat is dry acid woodland but it includes small fragments of neutral to base-rich woodland with high forage productivity), an estimate of the proportion of the mosaic area covered by these small but important fragments should be noted in section 3 of the plan.
Once you have defined your habitats, you will need to assess their current condition (in relation to herbivore impacts) and determine the biodiversity and, if relevant, the cultural heritage objectives for each.