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
  
• N : Coastal habitats
  
• 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
      
    • 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
      
      • U391 : Boreal and arctic serpentine and basaltic cliff communities
        
      • U392 : Boreal bare inland basaltic and ultra-basic cliffs
        
    • 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
    
    • U41 : Snow pack
      
    • U42 : Ice cap and glacier
      
    • U43 : Rock glacier and unvegetated ice-dominated moraine
      
  • 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
      
      • U621 : Italian fumaroles
        
      • U622 : Sicilian fumaroles
        
      • U623 : Pantelleria fumaroles
        
      • U624 : Macaronesian fumaroles
        
      • U625 : East Mediterranean fumaroles and solfataras
        
      • U626 : Peri-Alpine fumaroles, solfataras and mofettes
        
      • U627 : Western Asian fumaroles and solfataras
        
      • U628 : Teide violet community
        
      • U629 : Etna summital communities
        
      • U62A : Western Asian orovolcanic communities
        
      • U62B : Mediterranean, Macaronesian and temperate barren lava fields and flows
        
      • U62C : Mediterranean, Macaronesian and temperate volcanic ash and lapilli fields
        
• V : Vegetated man-made habitats