EUNIS habitat type hierarchical view (marine version 2022 & terrestrial version 2021)

The EUNIS habitat classification review is on-going. Four groups are pending review: Inland waters, Wetlands, Constructed, industrial and other artificial habitats and Complexes.

• M : Marine benthic habitats (MA-MG)
  
• MH : Pelagic water column
  
• MJ : Ice-associated marine habitats
  
  • MJ1 : Sea ice
    
  • MJ2 : Freshwater ice
    
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
• N : Coastal habitats
  
• Q : Wetlands
  
• R : Grasslands and lands dominated by forbs, mosses or lichens
  
• S : Heathland, scrub and tundra
  
• T : Forest and other wooded land
  
• U : Inland habitats with no or little soil and mostly with sparse vegetation
  
  • U1 : Terrestrial underground caves, cave systems, passages and waterbodies
    
  • U2 : Screes
    
  • U3 : Inland cliffs, rock pavements and outcrops
    
    • U31 : Boreal and arctic siliceous inland cliff
      
    • U32 : Temperate high-mountain siliceous inland cliff
      
      • U321 : Middle European siliceous cliffs of the sub-alpine, alpine and nival zones of temperate high-mountains
        
      • U322 : Bare temperate high-mountain siliceous inland cliff
        
      • U323 : Temperate high-mountain disused siliceous quarries
        
    • U33 : Temperate, lowland to montane siliceous inland cliff
      
      • U331 : Middle European lowland to montane siliceous cliffs
        
      • U332 : Helleno-Carpatho-Balkanic Silene siliceous cliffs
        
      • U333 : Lowland northern- and middle-European siliceous cliffs
        
      • U334 : Bare temperate lowland to montane siliceous inland cliff
        
      • U335 : Temperate lowland to montane disused siliceous quarries
        
    • U34 : Mediterranean siliceous inland cliff
      
    • U35 : Boreal and arctic base-rich inland cliff
      
    • U36 : Temperate high-mountain base-rich inland cliff
      
    • U37 : Temperate, lowland to montane base-rich inland cliff
      
    • U38 : Mediterranean base-rich inland cliff
      
    • U39 : Boreal ultramafic inland cliff
      
    • U3A : Temperate ultramafic inland cliff
      
    • U3B : Mediterranean ultramafic inland cliff
      
    • U3C : Macaronesian inland cliff
      
    • U3D : Wet inland cliff
      
    • U3E : Limestone pavement
      
  • U4 : Snow or ice-dominated habitats
    
  • U5 : Miscellaneous inland habitats usually with very sparse or no vegetation
    
  • U6 : Recent volcanic features
    
    • U61 : Subarctic volcanic field
      
    • U62 : Mediterranean, Macaronesian and temperate volcanic field
      
• V : Vegetated man-made habitats