Introduction to the guidance manual
9. Selection of attributes for interest features
9.1 Basic principles
Attributes are characteristics of an interest feature that
describe its condition, either directly or indirectly. They can be
regarded as indicators which allow judgements to be made about the
condition of the interest feature. The selection of attributes in
this guidance has been informed by two important principles:
- All attributes must be measurable, so that targets can
be set as part of the conservation objective for the
feature.
- Attributes should describe the condition of the feature
and not the factors which influence it – in general,
management activities are not suitable attributes. Thus in
determining if a calcareous grassland is favourable or not, one of
the attributes to be assessed may be sward height – this is what is
being aimed at, not the mechanism by which it is achieved, which
might be via grazing or by mowing.
9.2 Range of attributes
There are a wide range of suitable possible attributes. For
example, habitat attributes may include extent, floristic
composition, vegetation structure, and physical characteristics;
species attributes may include population size, distribution, food
availability, and habitat factors. Attributes for Earth science
features may include the quality and extent of landforms/rock
exposures and freedom from human induced influence in the case of
active geomorphological sites.
For habitat interest features, floristic or vegetative
attributes have generally been used as indicators of the condition
of the habitat. However, the definitions of favourable condition
for habitats are not based solely on maintaining suitable
conditions for plant species. In some cases, the requirements of
animal species have also been taken into account, and attributes
have, where possible, been selected which convey information about
the typical fauna associated with each habitat (e.g. structural
features and fine-scale patterning of vegetation). (See 'Attributes
for species interest features' in
section 10).
9.3 Mandatory attributes
During the preparation of the guidance, care has been taken to
select the minimum number of attributes which will allow reliable
assessments of condition to be made. These form a core set of
mandatory attributes which describe condition most economically,
and are intended to be suitable for use across the UK. An
assessment must be made of all of these attributes – each will
contribute to the final evaluation of feature condition. The
guidance adopts the term 'mandatory' to indicate these highest
priority attributes.
As a general rule, attributes have been chosen which do not
require expert knowledge, although staff will need training in
their use. However, in some cases the use of attributes requiring
additional (specialist) input is essential if a reliable and safe
evaluation of feature condition is to be made (e.g. lower plants
and some habitats such as cliffs and caves where specialised access
skills may be needed). These situations are highlighted in the
guidance.
9.4 Flexibility
However, some flexibility in the selection of attributes is
acceptable (see also
section 6). Some attributes may not be
applicable to all examples of a particular interest feature. For
example, encroachment of wetland species such as rushes is a
management issue in some lowland grasslands, and in such situations
the cover or frequency of wetland species is an important aspect of
feature condition, and should be used as an mandatory attribute.
However, in many dry grasslands use of such an attribute would be
irrelevant. Another approach is illustrated by the selection of
attributes for woodland habitats. Here, there are five
broadly-defined categories of attribute (such as regeneration
potential and tree and shrub composition) which should be
incorporated within conservation objectives for all woodland
features, but the selection of specific attributes within each of
these categories is determined by site-specific conditions.
Therefore, in some cases flexibility has been given in the guidance
to choose one or more of a number of alternative attributes. It
should be stressed that once chosen, it is mandatory that they are
assessed.
What is key, however, is that for any particular feature on an
individual site, a clear set of attributes are identified which
will be used to assess the feature each time it is
monitored. An audit trail of decisions which have been taken is
essential to document why this set of attributes is
necessary in the circumstances which apply on this site. Note that
it is NOT acceptable to assess the feature using totally different
sets of attributes between cycles of assessment.
9.5 Discretionary attributes
In addition, in a few cases (e.g. in the Birds guidance),
"discretionary" attributes have been identified. These lower
priority attributes will not contribute towards assessments of
condition but may inform site management. It is up to individual
agencies to determine whether or not to collect more detail than
the minimum required, as this is a matter of resources. In some
sets of guidance, there may be discretion to choose between
alternative attributes, or where attributes may only be relevant in
certain circumstances – these may also be termed discretionary, but
once a decision has been made that they are to be used on a
particular site, for a certain feature, they should be regarded as
mandatory.