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
    
    • MJ21 : Arctic freshwater ice
      
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
• N : Coastal habitats
  
• Q : Wetlands
  
• R : Grasslands and lands dominated by forbs, mosses or lichens
  
  • R1 : Dry grasslands
    
  • R2 : Mesic grasslands
    
  • R3 : Seasonally wet and wet grasslands
    
    • R31 : Mediterranean tall humid inland grassland
      
    • R32 : Mediterranean short moist grassland of lowlands
      
    • R33 : Mediterranean short moist grassland of mountains
      
    • R34 : Submediterranean moist meadow
      
    • R35 : Moist or wet mesotrophic to eutrophic hay meadow
      
    • R36 : Moist or wet mesotrophic to eutrophic pasture
      
    • R37 : Temperate and boreal moist or wet oligotrophic grassland
      
  • R4 : Alpine and subalpine grasslands
    
  • R5 : Forest fringes and clearings and tall forb stands
    
  • R6 : Inland salt steppes and salt marshes
    
  • R7 : Sparsely wooded grasslands
    
• 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
    
    • U11 : Cave
      
      • U111 : Troglobiont vertebrate caves
        
      • U112 : Subtroglophile vertebrate caves
        
      • U113 : Troglobiont invertebrate caves
        
      • U114 : Troglophile invertebrate caves
        
      • U115 : Subtroglophile invertebrate caves
        
      • U116 : Caves without vertebrates or invertebrates
        
      • U117 : Lava tubes
        
    • U12 : Disused underground mines and tunnels
      
  • 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
      
    • 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
    
• V : Vegetated man-made habitats