The climate and permafrost limits soil development in the archipelago. Large areas are void of soil, with permafrost polygons being the most common site for soil to occur. The soil typically has incomplete soil profiles and polygonal form with rich content of iron and either neutral or slightly acidic. The brown upper humus layers have three percent organic matter, increasing to eight percent in the southernmost islands. Arctic desert soils occur on the eastern group islands, while the areas near the edge of the glaciers can give semi-bog arctic soil.