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The Essex Naturalist
Essex Scarce species which are restricted to habitats or
sites known to be under threat in the county e.g. from
agricultural improvement, development or
inappropriate management.
species which have shown a continuous decline over
the last twenty years.
Regionally Important species which are important in a national context
because the county contains a significance proportion
of the national populations.
species which are important in a national context
because they have a close association with a specific
nationally threatened habitat included in the
Biodiversity Action Plan.
species which are important in a national context
because they are dominant in or peculiar to a specific
habitat for which the county contains a large
percentage of the national habitat.
For many invertebrates and the more widespread species of ant there is not
enough historical information at a county level to scientifically evaluate changes
in status. No species of ant would at present be included in a Threat category on
the basis of a known decline.
Species not assigned an Essex Threat status are assumed to be under no direct
threat of severe decline or extinction in Essex at the present time or the county
is not known to contain a significant proportion of the national populations of
the species.
Table 1 provides a list of the species recorded in Essex with their rarity and
threat statuses.
Significant assemblages of ants in Essex
Of the 27 native species of ant with modern records in Essex five are Common
in the county, six Local and one Unknown. Of the remaining species nine are
Scarce and six Rare.
Sites will be of ecological significance where rare species are present in
habitats which although not species-rich in ants do contain species with
specialist ecological requirements. Examples include species such as Myrmica
bessarabica at sea wall, grazing marsh, relic dune sites and Lasius brunneus in
ancient woodland and pasture woodland sites.
Since even the common species have various ecological requirements and
occur in different habitats or sub-habitats, a single locality is unlikely to have all
the common and widespread species unless a suitable diversity of habitat is
present. Most localities however do have a variety of habitats represented and the
biodiversity associated with these habitat complexes is in itself important. Sites
may be of ecological value simply because they have all the common species.