Title: Assessment of the impact of different revegetation methods on soil carbon stocks in Iceland

Soils have more capacity to store high amounts of carbon than vegetation in the terrestrial carbon pools. The objective of the study was to assess the impact of time, reclamation methods and spatial variation on carbon concentration in soils on reclamation sites in Iceland. A total of 60 reclamation sites were studied. At each site, samples were collected from 10 m x 10 m plots in which five sub plots of 0.5 m x 0.5 m area were selected randomly for the above- and below-ground biomass and soil sampling. The reclamation methods included in this study were: a) sowing of Alaska lupine (Lupinus nootkatensis), b) sowing of a mixture of grass species and c) fertilization. For comparison, soils from control plots were sampled and analysed. The results showed that the method and the spatial variation of reclamation sites have a very highly significant effect on carbon concentration. However, the time length since reclamation started was found to have no statistically significant effect. Fertilizing the plots for reclamation did give a significantly higher carbon concentration compared to control plots. This was not the case when the plots were sown with lupine or grass species. For an efficient operation of all the methods, it is important to study the soil physical and chemical properties and the nutrient demand of the different methods of reclamation. This helps to apply the right method of reclamation in the appropriate soil type and to increase the productivity of the method.