Faddan More Psalter used as a liner to stiffen the cover somewhat. Low oxygen levels in the bog provide unusual preservation conditions, and bogs were often used by Irish monks as hiding places for valuables in the face of Viking raids. In addition to low oxygen levels, sphagnum moss, of which the peat bog is composed, produces an antibiotic substance called sphagnan that binds with proteins on the surface of microorganisms, immobilising them. Its highly reactive carbonyl groups can alter chemicals and nutrients that would otherwise decompose organic matter. And above all the sphagnum moss causes organic material to undergo chemical changes itself
Aulacomnium palustre plant communities, and individual moss species often have low cover and/or frequency. Moss species with coverages of 2% to 4% can be common to dominant in boreal communities, although ribbed bog moss attains coverages as great as 40% in some boreal communities. Ribbed bog moss grows in open and forested wetland communities. In unforested northern communities, ribbed bog moss is found in sedge ("Carex" spp.) meadows, sphagnum ("Sphagnum" spp.) peatlands, heath-sedge fens, and willow ("Salix" spp.)-dominated fens. In forests, ribbed bog moss grows in the ground layer of boreal and subboreal white spruce ("Picea glauca"), black spruce ("P. mariana"), mixed