What is a raised bog?

Raised bogs are among the world’s oldest living near natural eco-systems. Many of Ireland’s raised bogs have taken 10,000 years to develop.

Raised bogs began to develop in depressions occupied by shallow lakes left behind by retreating glaciers after the last Ice Age.

Reed swamp and fen peatlands formed, peat began to form, and peat depth increased to the level where the surface vegetation could no longer be influenced by mineral-rich ground waters or surface waters. The vegetation changed to plant species which grew and tolerated more acidic conditions, and the low-nutrient conditions provided by rainwater. The plant species that grew and was dominant under these changed conditions was Sphagnum mosses and other bog species such as Heather and Bog Cotton.

Sphagnum Mosses

The Raised Bog peat formed when the Sphagnum mosses partially decayed and accumulated in annual cycles over thousands of years in the anaerobic water­logged environment.

Sphagnum mosses are very important in the formation of Raised Bogs as they act very much like a sponge in that they draw up and hold water as they grow. They have the unique property of being able to hold up to 20 times their own weight of water in their pores and cells.  In some situations, there can be a greater water content in a bucket of Sphagnum compared to a bucket of milk.  Sphagnum mosses are also particularly beautiful when examined closely and come in lots of different colours and shapes

Industrial Peat Production

Raised bogs have been utilised by Bord na Móna since the 1940’s for the production of milled and sod peat for energy, fuel and horticultural use.

Peat production has now ceased on many of these bogs and large areas are now available for enhanced decommissioning and rehabilitation.

Bord Na Móna have now ceased production on all of their bogs.