Afforestation: ‘The rate of sequestration changes as forests develop and mature’

Carbon sequestration by forests is influenced by a range of factors including species, soil type, site conditions and management practices. Irish forests are currently estimated to sequester 3.8Mt of CO2 per year.

These were the sentiments expressed in the Dáil last week by the Minister for Agriculture, Food and the Marine, Michael Creed, after he was asked by Fine Gael’s Bernard Durkan about the extent to which 1,000ac of Sitka spruce can sequestrate a specific amount of carbon.

Durkan also asked the minister what is the extent to which 1,000ac of ash, oak or beech can sequestrate a specific amount of carbon?

The minister pointed out that, on average, a productive hectare of spruce forest may sequester 10t of CO2 per year over a 35-year period.

This would mean 1,000ha of spruce would sequester 10,000t per year or at least 350,000t over its lifetime.

He continued: “The rate of sequestration changes as a forest develops and matures. My department has funded a number of large-scale research projects which have examined carbon stocks and stock changes in Irish forests.

“For example, the carbon stocks in a Sitka spruce forest and an ash forest at different ages have been measured, and are available in a number of published journal articles.”

Meanwhile, the minister pointed out that the work undertaken returned results that found – after 47 years – an ash forest and Sitka spruce forests had 177.8 and 376.7t of carbon/ha respectively.

He also added that the figures were specific to the forests and soils examined and could not be used to reflect all forests of these species.

“My department is also funding the new forestry module on the Carbon Navigator which is being developed by Teagasc and An Bord Bia and this tool will describe indicative carbon stocks in a range of forest types,” Minister Creed concluded.