Ecosystem Accounts – Forests and Woodlands 2012-2022 OLD

Services Accounts

Forests & Woodlands provide a wide range of ecosystem services - in this publication, we will focus on two - Wood provision and Global climate regulation.

The Wood provision ecosystem service is the contribution of ecosystems to the increase in timber available for harvesting. This is measured as the net annual increment, or increase in volume, of timber. For ecosystem accounting, and for economic accounting, a distinction is made between Forests Available for Wood Supply (FAWS) and Forests Not Available for Wood Supply (FNAWS). The net annual increment for FAWS is considered the wood provision ecosystem service provided to society by Forests & Woodlands, as this is the increase in wood available to be harvested from managed forests. 

The Global climate regulation service is the contribution of ecosystems to reducing concentrations of greenhouse gases in the atmosphere. In this case, we are focusing on the removal (net sequestration) of carbon from the atmosphere and the retention (storage) of carbon in ecosystems. 

In an ecosystem accounting context, supply and use tables are accounting tables structured to record flows of final ecosystem services between ecosystems and economic units. Entries can be made in physical and monetary terms, and the tables are designed to be coherent with the System of National Accounts.  

In 2022 the volume of timber available for harvesting in Forests & Woodlands grew by more than 9 million m³. Because all of this has the potential to be harvested by the Forestry industry, all of this growth was classified in the Use table as Intermediate consumption by industries (Table 4.1). In 2021 Forests & Woodlands removed 320,881 tonnes of carbon from the atmosphere (this is the net sequestration figure), and stored more than 322 million tonnes of carbon. The beneficiary of this Global climate regulation service is considered to be society in general, so all of the use of this service is allocated to Government final consumption in the Use table (Table 4.2). See Background Notes for more information on Supply and Use tables in ecosystem accounting. 

Wood Provision

The National Forest Inventory provides data on the net annual increment of timber in Ireland's Forests & Woodlands. Not all of these forests are used for wood supply, however. In the National Forest Inventory, forest area is categorised as Forest Available for Wood Supply (FAWS), or Forest Not Available for Wood Supply (FNAWS; split into Unlikely and Not available). These categories are defined as:

Available - Forest where any legal, economic, or specific environmental restrictions do not have a significant impact on the supply of wood. 

Unlikely - Forest where physical productivity or wood quality is too low or harvesting and transport costs are too high to warrant wood harvesting, apart from occasional cuttings for own use.

Not available - Forest with legal restrictions or restrictions resulting from other political decisions, which totally exclude or severely limit wood supply, inter alia for reasons of environmental or biological diversity conservation, e.g. protected forest and other protected areas, such as those of special environmental, scientific, historical, cultural or spiritual interest. Areas classified as National Parks and Nature Reserves are included in this class.

The mean net increment per hectare for all forests has increased every year since 2012, from 11.6m³/ha in 2012 to 14m³/ha in 2022. As the area of forests has also grown over time, the mean annual net increment has increased by 35%, from 7.391 million m³ to 9.984 million m³. The increment of FAWS has increased from 13.1m³/ha in 2012 to 17.1m³/ha in 2022, with the total annual net increment increasing from 6.992 million m³ in 2012 to 9.064 million m³ in 2022, an increase of almost 30%. Figure 4.1, Table 4.3.

Global Climate Regulation - Carbon Storage

The National Forest Inventory provides a detailed breakdown of how carbon is stored in various carbon pools in Forests & Woodlands. Carbon stored in the soil is by far the largest carbon pool, with 78% (252 million tonnes) of the total carbon stock of Forests & Woodlands in 2022. The Aboveground carbon pool, i.e. the carbon stored in the above ground portion of the living trees, is the next largest component, at more than 16% (52.574 million tonnes), followed by the Belowground pool, i.e. the carbon stored in the living tree roots, at 3.8% (12.259 million tonnes) in 2022. Altogether, the living trees stored around 20% (64.833 million tonnes) of the total carbon stored in Forests & Woodlands in 2022. The rest of the carbon is stored in the Deadwood and leaf litter. The total carbon stored in Forests & Woodlands in 2022 was 323 million tonnes, an increase of nearly 13% on 2012. Figure 4.2a, Figure 4.2b, Table 4.4.

Global Climate Regulation - Carbon Sequestration

The EPA produces a National Inventory Report every year which details Ireland's emissions and removals of greenhouse gases. This report and the accompanying tables are a rich source of data on greenhouse gas emissions and removals for different types of land cover. Using these data, we have compiled figures for carbon removed from the atmosphere, carbon emitted due to burning, and carbon removed from the ecosystem as Harvested Wood Products (HWPs). 

The net carbon stock change in living biomass has decreased from 1.5 million tonnes in 2012 to 0.58 million tonnes in 2021. The carbon stock gains in living biomass have shown a small amount of variation over this time, going from 5.3 million tonnes in 2012 to 5.7 million tonnes in 2021. The carbon stock losses in living biomass have shown an increase almost every year, however, from -3.8 million tonnes in 2012 to -5.1 million tonnes in 2021. Figure 4.3, Table 4.5.

The carbon stock changes in the different components of the forest ecosystems are shown in Figure 4.4 and Table 4.7. The largest component is the living biomass, which has already been described above. The next largest component is the loss of carbon from organic soils. This loss has increased from 694,010 tonnes in 2012 to 732,305 tonnes in 2021, an increase of 5.5%. The carbon sequestered shows the sum of the stock changes. This has shown a decreasing trend, dropping from 1.04 million tonnes in 2012 to 326,847 tonnes in 2021. The amount of carbon emitted due to burning varies by year; the lowest amount in this period was 2,147 tonnes in 2016, while the highest was 112,889 tonnes in 2017.  The carbon emitted due to burning is subtracted from the carbon sequestered to provide the net carbon sequestered. The net carbon sequestered has been decreasing from a high of 1.21 million tonnes in 2016 to 320,881 tonnes in 2021.

Ireland's forest age class structure is unusual due to large legacy afforestation events in the 1950s and again in the 1980s due to the introduction of afforestation grants and schemes. The main drivers of the changes in net carbon sequestered are due to the area of forest on organic soils, increased harvest rates, and a shift in age class structure. An increase in timber removals (Table 4.6; see CSO's Forest Wood Removals 2021 for more information) has resulted in increased carbon stock losses from the living biomass, and a resulting decrease in the net change in carbon stock in the living biomass (Table 4.5). Around 59% of Forests & Woodlands occurred on drained organic soils in 2021 (National Inventory Report 2023). Young plantations on organic soils result in increased carbon stocks in the soil, but as these mature there is a net loss of carbon. 

Harvested Wood Products (HWPs) are wood-based materials harvested from forests, which are used to make products including furniture, construction materials, or for energy. They form a storage pool or stock of carbon that has been extracted from the ecosystem, but which has not yet been released back into the atmosphere. The carbon in HWPs was 262,550 tonnes in 2021, the highest over the 2012-2021 period. Table 4.8.