A significant amount of organic soils in Ireland were afforested during the second half of the 20th century. These areas were initially planted to create rural employment at a time when the importance of other functions, such as carbon storage, was not well understood.
When assessing the benefits of growing forests on organic soils, it is very important to consider the losses of carbon from organic soils as the removals from the growing forests may not offset the emissions from the drained organic soil.
A 2005 study of forests on blanket peats found that these areas emitted 0.59 tonnes of carbon per hectare per year. More recent research from 2021 funded by my Department has shown that forested blanket peatlands are emitting 1.68 tonnes of carbon per hectare. This new research has shown that emissions from forested peatlands are three times higher than previously estimated.
The significantly increased new emission factor for organic soils has been incorporated into the national inventory reporting to the United Nations Framework Convention on Climate Change.
The Department is currently finalising a new Forest Strategy 2023-2030 and associated implementation plan. As part of this process a cost-benefit analysis was undertaken which included an assessment of the benefits in terms of carbon removals by the proposed new forests.
Afforestation is now predominantly occurring on mineral soil types and the level of afforestation on organic soils is continuing to decrease. This trend is expected to increase in the next Forestry Programme 2023-2027.
When assessing the annual carbon sequestration rate of the proposed new forests during the cost-benefit analysis it is was assumed that all afforestation was on mineral soil. Therefore, the new emission factor for organic soils were not required to be incorporated into the analysis.
