The national land resource database (AR) classifies the land cover of mainland Norway according to its suitability for agriculture and natural plant production. National land resource datasets are available at scale 1:5.000 (AR5), 1:50.000 (AR50) and 1:250.000 (AR250). AR5 is a national, seamless land resource database. The dataset describes land resources (mainly land cover and productivity) based on a standardized national classification system with 104 classes. Special attention is given to the suitability of land for agricultural and forest production. Substantial areas of Norway are above the tree line. These areas are only mapped as “not classified” in AR5. Areas above the tree line have been mapped in AR50. Features in AR5 are continuous areas with the same attributes assigned according to the classification criteria of AR5 with a geometric representation as polygons. The minimum mapping unit in AR5 is 0.05 hectare (500 m2) for agricultural areas, transport networks and water bodies. Furthermore 0.2 hectare (2000 m2) is the minimum mapping unit for forest, peat bogs and open areas. For urban areas the minimum mapping unit is 0.5 hectare and 2.5 hectare for perpetual snow and glaciers. The geometric accuracy for well-defined boundaries is 2 m or better. The point density is normally between 5 and 50 m. AR5 is continually updated by municipal administrations and priority is given to agricultural- and urban areas. This is an integrated part of the maintenance of the municipal geospatial database. A centralized control and editing program is carried out by NFLI with a five year turnover period.

Land type is the main classification theme in AR250 based on vegetation, natural drainage and cultivation. Main classes are: 10 Built-up area and transportation networks; 20 Cultivated land; 30 Forest; 60 Peat bog; 50 Open land; 70 Glacier and permanent snow; 81 Fresh water; 82 Salt water; The national land resource database (AR) classifies the land cover of mainland Norway according to the suitability for agriculture and natural plant production. National land resource datasets are available at scale 1:5.000 (AR5), 1:50.000 (AR50) and 1:250.000 (AR250). AR250 is the Norwegian low resolution land resource dataset, covering the entire mainland Norway. It is built and maintained for cartographic presentations at regional level (1:100.000 to 1:300.000). The dataset is not intended for spatial analysis. Features in AR250 are continuous areas represented as polygons with attributes assigned according to the classification criteria of AR250. The primary level of classification is land type (arealtype), based on a combination of land cover and land use. Second level attributes are forest site quality class (skogbonitet) and forest cover type (treslag). AR250 also includes information about arable land on current bare land, marsh or forest. In AR250, the general minimum mapping unit is 10 hectares for polygons that have identical combinations of attribute values. Smaller mapping units occur between identical land types if they have different forest cover or forest site quality.