Case Study: Machair – a unique ecological environment threatened by sea-level rise

The machair is a unique habitat occupying 25,000 hectares of the low-lying Atlantic coasts of the Scottish mainland, the Western Isles and Ireland. Its proximity to the sea and dependency on the supply of seaweed and shells that are brought ashore by storms makes sea-level rise a real threat for the ecosystem.

For a few weeks each summer, it is a carpet of beautiful wildflowers of many different shapes, sizes and colours. Rare species, such as Irish Lady’s Tresses, orchids and Yellow Rattle provide a home for a diverse array of birds, as well as rare insects such as the Northern Colletes bee.

Although the machair is not an entirely natural system, in that much of it has been managed for generations, it only survives because of its close proximity to the sea.  And so the machair exists in a delicate balance with the sea, which provides a dressing of lime-rich shell sand, helping to neutralise the acid from the peaty soil to create an alkaline environment – this produces a fertile environment.

In the worst case scenario of substantial rising sea-levels, and significantly increased flooding, the land will become irreversibly salt-damaged and a unique ecological system could be lost.

Some machair is already threatened by coastal erosion, but this would be exacerbated by rising sea-levels as well as by recreational use of nearby beaches.

 

For more information see: UK Biodiversity Action Plan

Photographs: http://www.virtualheb.co.uk/machair-wildflowers-western-isles.html

Issues: http://www.machairlife.org.uk

Summary: http://www.snh.org.uk/pdfs/publications/livinglandscapes/machair.pdf