The
primary habitat matrix provides a general
framework for the classification and shows the level 2 and 3 types.
In addition, more detailed matrices have been created for each of
the broad habitats, showing the distribution of individual biotopes
and sub-biotopes (levels 5 and 6) in relation to key habitat
factors. The format of these matrices has changed significantly
from previous versions of the classification to better depict the
relationship of biotopes to habitat factors. For the rocky
habitats, biotopes are shown in relation to energy levels, whereas
for sediment habitats, biotopes are shown in relation to sediment
type using a modified Folk triangle approach (Folk 1954).
The matrices aim to provide a rapid indication of the range of
biotopes that could occur under particular habitat conditions, e.g.
moderate energy infralittoral rock or intertidal sandflats. They
can be used to indicate which closely related biotopes should be
considered before determining to which type a sample record should
be assigned.
Presentation of the biotopes and sub-biotopes within these
matrices has a number of benefits:
- It helps to display the relationship of a biotope to other
closely related types and to clarify the main habitat parameters
which contribute to its structure. These relationships are less
clear in a more conventional listing of types (e.g. the
hierarchical listing).
- It enables the identification of dissimilar communities within
apparently similar physical environments. Here, although there may
be subtle physical factors which drive such differences in
biological composition, other factors such as seasonal change,
chance recruitment, grazing pressures or pollution effects may
account for the differences and allow such communities to be linked
within the classification.
- It also facilitates the undertaking of new ecological survey in
a more structured manner, by enabling the full range of habitats in
an area to be identified and sampled.