Soils of the European Union - European Soil Portal - Europa

4. Spatial distribution of the major soils in the European Union4.1 AcrisolsGeographical distributionAcrisols cover about 10,000 km 2 , 0.26% of the surface area of the EU. Most of the European Acrisols are located asassociated soils on the Iberian Peninsula and in Greece, but also can be found in Southern England, Denmark and in limitedareas in Romania and Bulgaria. They form the dominant soil in six associations and occur as associated soils in 70associations and as inclusions in 372 cases.Five soil units of the Acrisols Reference Soil Group can be found in the EU with Gleyic Acrisols and Haplic Acrisolsoccupying more than 90% of their area (Table 4.1, Figure 4.1).Table 4.1 Area of the second level units of AcrisolsUnits in the Reference Soil Groupin the EUCodes ofsoil unitsArea in the EUkm 2Ferric Acrisol ACfr 178Gleyic Acrisol ACgl 3359Haplic Acrisol ACha 6277Humic Acrisol AChu 803Plinthic Acrisol ACpl 10Ferric Acrisols with their rather small era coverage can be found in Southern Portugal. Gleyic Acrisols occupyconsiderably larger areas and situated mainly on the south-western plains of Spain. Haplic Acrisols can be found in nearlyall Acrisol areas of the EU, mostly as inclusions among other soils. Humic Acrisols are widespread in Denmark asassociated soils. Plinthic Acrisols have very small spatial extend which is limited to some inclusions in soil associations inPortugal.0.09%7.56% 1.67%31.61% ACfrACglAChaAChuACpl59.07%Figure 4.1 Share of the second level soil units in the area of AcrisolsGlobal referenceAcrisols are highly weathered soils occurring in warm temperate regions and the wetter parts of the tropics and subtropics.Acrisols develop mostly on old land surfaces with hilly or undulating topography with a natural vegetation type of a lightforest. Being quite sensitive to erosion, Acrisols are often the dominant soil group on old erosional or depositional surfaces.There are approximately 10 million km 2 of Acrisols world-wide.Acrisols can be characterized by accumulation of low activity clays in an argic subsurface horizon and by a low basesaturation level. The chemical properties of Acrisols are quite poor, containing low level of nutrients and high levels ofaluminum. These conditions mean rather limited soil use options.Acrisols correlate to several subgroups of Alfisols and Ultisols of the Soil Taxonomy of the USDA, Desaturated FerraliticSoils of France and are similar to Red-Yellow Podzolic soil in Indonesia.12