Eskers

Restoration and management in an SAC using traditional methods and seed sourced by harvesting from undamaged part of the site.

In this study carried out by Michael Martyn on a multi designation site with an esker series which is part of All Saints Bog and Esker Special Area of Conservation (SAC – 000566), Special Protection Area (SPA – 004013) and Natural Heritage Area (NHA – 000566) north-west of Birr, Co. Offaly, and separated from the Little Brosna Callows Special Protection Area (SPA – 004086) and Natural Heritage Area (NHA – 000564) by the Esker series and a public road running roughly north/south. The designated site contains three EU Habitats Directive Priority Habitats, Active Raised Bog, Bog Woodland and Orchid-rich calcareous grassland.

In addition cutover bog, improved grassland, lowland wet grassland/callows and sand pits occur in the designated site. The Special Protection Area (SPA 004013) is designated under the EU Birds Directive. The qualifying interest is the presence of the Annex I Bird species Greenland White-fronted Goose (Anser albifrons flavirostris) and Merlin (Falco columbarius). It is also managed for waders. The central area of All Saints bog is fed with mineral-rich water from subsurface springs thought to come from a source in All Saints Esker. The scientific interest of the site includes the unusual hydrology resulting in the birchwood spring flush which is unique in its extent and structure. This bog woodland is a priority habitat under the Habitats Directive.

The All Saints esker also contains EU Habitats Directive Priority Habitat, Orchid-rich calcareous grassland. A population of Green-winged orchid (Orchis morio) occurs on the esker ridge on the site. The orchid-rich calcareous grassland found on this site is one of the best examples of this habitat type remaining in the country. Both habitats are dependent on maintaining the hydrological system of the esker ridge. It is considered to be a relict “Ancient Woodland”, and as such a natural habitat type.

This excerpt from the study (Michael Martyn, unpublished) shows the inter-relatedness of the habitats in a “farm sized” area. A conservation management plan on this farm sized area, properly constructed will take cognisance of the integrated nature of these habitats and their relation to each other as well as the legally binding regulations, the multiple designations impose on the occupier and the land use.