Potential and Challenges of Soil Carbon Sequestration in Iceland
2009
Lal, R.
Soils of Iceland are severely degraded and land resources desertified due to anthropogenic perturbations since AD. 875. Of the total area of 10.3 million hectares (Mha), the land area is 10.0 Mha. Land cover, at the time of settlement 1100 years ago comprised 6.5 Mha of vegetation cover, of which 3.0 Mha was birch (Betula pubescene) woodland and 3.5 Mha other vegetation. At present, the land area under some vegetation cover is only 2.8 Mha, of which highly productive birch cover is only 0.125 Mha. There are 3.7 Mha of severely eroded and barren lands in Iceland. The fossil fuel emission was 0.7 Tg C yr-1 in 1990, 0.82 Tg C yr-1 in 2000, and is projected to be 0.9 Tg C yr-1 in 2010 and 0.95 Tg C yr-1 in 2020. Afforestation and adoption of recommended management practices (RMPs) can lead to terrestrial C sequestration at the rate of 0.01 to 0.05 Mg C ha-1 yr-1 (1 Mg = megagram = 10(6) g = 1 tonne) in degraded rangeland soils by establishing native lyme grass (Leymus arenarius) and soil organic carbon (SOC) sequestration at the rate of 0.7 to 0.8 Mg C ha-1 yr-1 through N fertilization. Effective erosion control can lead to emission avoidance of 0.01 to 0.02 Tg C yr-1, and restoration of eroded soils to C sequestration of about 1 Tg C yr-1. Potential of terrestrial C sequestration in Iceland is 1.2 to 1.6 Tg C yr-1, which can effectively offset fossil fuel emission by 2025 and beyond, and make Iceland an emission-free nation.
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