Photosynthesis in plants mediates carbon sequestration by splitting atmospheric carbon dioxide into oxygen and carbon. Plants utilise this carbon, derived from the atmosphere rather than the soil, as a primary structural component. Terrestrial ecosystems accumulate carbon reserves within both plant biomass and soil organic matter. Net carbon sequestration occurs when vegetation growth and the accumulation of plant residues exceed decomposition rates.

Intact, sustainably managed ecosystems are significant carbon sinks. This includes diverse environments such as Icelandic moorland and grassland; conversely, degraded moorland and grassland are potential sources of carbon emissions. Greenhouse gas mitigation strategies focusing on vegetation typically prioritise wetlands and forests. Wetland drainage introduces oxygen to accumulated organic matter, initiating decomposition and substantial carbon release. Conversely, wetland restoration, by raising water levels, halts this decomposition and reduces emissions. Forest growth results in substantial net carbon sequestration, accumulating carbon in both biomass and soil.

Forestry and wetland restoration demonstrably contribute to climate change mitigation. However, to ensure project accountability and reliability, robust, nationally standardised measurement protocols, validated by peer-reviewed scientific research, are essential. Data indicates significant carbon sequestration by Icelandic forests, increasing annually with forest growth, mirroring the emission reductions achieved through wetland restoration. Extensive international research has explored the impact of grazing on emissions and carbon sequestration; Icelandic studies similarly demonstrate variable effects (increased emissions, neutrality, or increased sequestration) contingent upon land type and grazing management practices.

The UN Framework Convention on Climate Change mandates rigorous standards for data collection and reporting.

Misleading news report

The statement made in the RÚVs news report, "The plants are working on the carbon that the grasslands have already bound; the soil carbon is shrinking and is moving up into the trunk," is factually incorrect. Grassland carbon sequestration primarily occurs in the soil, exceeding that of forests when considering soil carbon alone, although not the entire ecosystem. This does not indicate that trees draw carbon from the soil and transfer it to their trunks and branches. Trees are predominantly composed of carbon, largely above ground, with a significant portion in their root systems. Live tree roots are excluded from soil carbon stock assessments but are integral to the tree's biomass. All this carbon originates from atmospheric carbon dioxide via photosynthesis.

Sustainable forestry practices do temporarily reduce ecosystem carbon levels due to timber harvesting. The forestry sector is transitioning towards selective logging, replacing clear-cutting. The carbon sequestration timeframe depends on the timber's end-use; products like building materials retain carbon longer than those rapidly releasing it, such as burned wood. Nevertheless, wood combustion remains a preferable alternative to oil combustion.

It is also important to note that timber construction offers a significantly lower carbon footprint compared to steel and concrete construction. Sustainable forestry practices ensure reforestation following harvesting, leading to continuous carbon sequestration. Sustainable timber harvesting replaces aging trees, maximising growth and carbon capture, unlike mature, unharvested forests which exhibit significantly reduced carbon sequestration despite substantial carbon reserves. The key is the implementation of sustainable forestry methods.

Forestry not on arable land

Forestry practices in Iceland have traditionally focused on non-arable land, primarily unimproved pasture . While some historical exceptions exist, current forestry initiatives prioritise integration with agriculture, ensuring no impact on food production. Land and Forest Iceland, in collaboration with other stakeholders, is developing a comprehensive national land-use plan and quality criteria for forestry projects. These criteria explicitly exclude the use of prime agricultural land for forestry unless it directly benefits agricultural or livestock operations. Furthermore, the potential for future land-use conversion after forest harvesting is acknowledged. Expanding native birch forests and establishing new commercial forests for economic, environmental, and societal benefits remains a key objective.

Comprehensive planning, rigorous research, and effective oversight

Comprehensive planning, rigorous research, and effective oversight are critical. In RÚV' news report, concerns were raised regarding Icelandic forestry methods, knowledge base, structural organisation, scale, and carbon sequestration levels. To clarify, Iceland maintains meticulously detailed maps of its forests, encompassing both native birch and planted areas. Our national forest inventory, leveraging over a century of expertise and Scandinavian methodologies, is globally recognised for its excellence. Geospatial data is readily accessible through online map viewers. Forest monitoring is systematic, with annual database updates reflecting forest expansion. Furthermore, the environmental impact of forestry is rigorously assessed through monitoring projects like the Icelandic Forest Audit, which annually measures 200 plots nationwide.

Specialised research initiatives, such as the Skógvist project, analyse the ecological impact of afforestation. Research findings and monitoring work inform the ongoing development of Icelandic forestry practices. All forestry projects adhere to legal and regulatory stipulations encompassing master and divisional planning, preservation of monuments and natural areas, and other considerations. Municipal permits are required for new forestry projects.

Optimal land use necessitates leveraging current best practices and maintaining a professional discourse, ensuring comparable analyses, addressing knowledge gaps, and guaranteeing equitable outcomes. Adherence to the scientific method and ethical principles is crucial for continuous knowledge enhancement. Land and Forest Iceland is actively expanding its understanding of carbon farming across diverse ecosystems, including wetlands, forests, and arid lands. Improved data ensures the accuracy and reliability of Iceland's carbon accounting submissions to international climate initiatives.

The staff of Land and Forest Iceland is committed to fostering robust discussion and productive dialogue on critical land reclamation and forestry issues. Our approach is grounded in the most current scientific understanding, a standard we encourage others to adopt. We are available to provide information upon request.

Ágúst Sigurðsson, General Director, Bryndís Marteinsdóttir, Director of Sustainable Land Use, Brynjar Skúlason, Director of Research and Development, and Pétur Halldórsson, PR Manager

• A link to the RUV news report: https://www.ruv.is/frettir/innlent/2025-02-02-kolefnisbinding-mun-meiri-i-beitilandi-en-skogi-434837