Plantation forestry on cutaway raised bogs and fen peats in the Republic of Ireland.

Abstract

Coniferous plantations have been established on sizeable areas of handcutaway raised bogs and modified fen peats in Ireland over the last thirty years. Whereas Scots pine and Norway spruce were used almost exclusively up to the mid 1960s, Sitka spruce has now become the dominant species because of its higher production potential (20m3/ha+). Mixtures of Scots pine and Norway spruce were often used where competition from heather was envisaged on the handcutaway bogs. Phosphorus and potassium application are essential on the handcutaway peat types in order to ensure good growth. There are increasing indications that copper application may also be necessary, particularly for pines and Sitka spruce. Potassium application alone is essential on the modified fen peats. Although Scots pine grew well in the early years on many of the site types described there is increasing evidence of die back at about 25 years of age on handcutaway sites, the causes of which are under investigation. Machine cutaway bogs, both sod peat and milled peat, appear to have a high production potential for forestry (22-24m3/ha). However, further research is necessary on milled peat bogs to ensure this potential is attained. The depth of peat left behind will be critical because of the highly calcareous nature of many of the underlying subsoils.