The mite (Arachnida: Acari) fauna inhabiting Irish machair: a European Union priority coastal habitat

Machair is a highly specialised and complex sand dune habitat confined globally to the west coasts of Ireland and Scotland. Irish machair is designated as a priority habitat under the EU Habitats Directive, with the habitat coverage restricted to the machair grassland. The main goals of the study were to describe the Acari fauna inhabiting the Irish machair and to determine the uniqueness of its mite communities in the context of habitat protection. Ten Irish machair sites were selected and samples were taken from the machair grassland and from two types of dunes within the wider machair system: shifting dunes (foredunes) occurring at the beach and stable (fixed) dunes located in the transition zone to the inland grassland flat areas. One hundred and eleven mite taxa were recovered. The most widespread was Scutovertex cf arenocolus Pfingstl et al. 2009, a halophilous species that has been found in the epilittoral zone of Baltic and European Atlantic coasts. The genus Autogneta Hull 1916 (Oribatida: Oppiidae) and the oribatid species Hermaniella granulata (Nicolet 1855) were recorded for the first time for Ireland. Peloptulus cf gibbus Mihelčič 1957, may also be a new record. Multivariate analysis showed that community composition varied between the areas sampled in the machair systems and that in the machair grassland, an Annex I priority habitat in Ireland, was especially different from both dune types sampled. The assemblages also varied significantly between the different sites sampled in the study.