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
  
  • MH1 : Neuston
    
  • MH2 : Completely mixed water column with reduced salinity
    
  • MH3 : Completely mixed water column with full salinity
    
  • MH4 : Partially mixed water column with reduced salinity and medium or long residence time
    
  • MH5 : Unstratified water column with reduced salinity
    
  • MH6 : Vertically stratified water column with reduced salinity
    
  • MH7 : Fronts in reduced salinity water column
    
  • MH8 : Unstratified water column with full salinity
    
  • MH9 : Vertically stratified water column with full salinity
    
  • MHA : Fronts in full salinity water column
    
• MJ : Ice-associated marine habitats
  
• 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
    
    • U11 : Cave
      
    • 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
      
    • 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
      
      • U361 : Central Pyrenean calcicolous chasmophyte communities
        
      • U362 : Liguro-Apennine calcicolous chasmophyte communities
        
      • U363 : Alpine and sub-mediterranean chasmophyte communities
        
      • U364 : Temperate high-mountain bare limestone inland cliffs
        
      • U365 : Temperate high-mountain disused chalk and limestone quarries
        
    • 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
      
      • U3A1 : Tempearate bare inland basaltic and ultra-basic cliffs
        
      • U3A2 : Temperate serpentine and basaltic cliff communities
        
    • 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