Spruce forest expansion have been blocked by Saltfjell and Kjølen mountains, thus spruce forest naturally grows only in Helgeland, but are commonly planted in the whole county for economic reasons, sparking some debate. Sitka spruce is also commonly planted in Nordland, particularly in coastal areas. The coastal areas belong to the Scandinavian coastal conifer forests ecoregion; some small areas have been classified as rainforest using botanical criteria as well as precipitation data. Inland areas up to the conifer treeline belong to the Scandinavian and Russian taiga ecoregion, while the highlands and mountains belong to the Scandinavian Montane Birch forest and grasslands ecoregion.