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
    
    • MH21 : Arctic completely mixed water column with reduced salinity
      
      • MH211 : Arctic completely mixed water column with reduced salinity and short residence time
        
      • MH212 : Arctic completely mixed water column with reduced salinity and medium residence time
        
      • MH213 : Arctic completely mixed water column with reduced salinity and long residence time
        
    • MH22 : Atlantic completely mixed water column with reduced salinity
      
    • MH23 : Baltic completely mixed water column with reduced salinity
      
    • MH24 : Black Sea completely mixed water column with reduced salinity
      
    • MH25 : Mediterranean 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
    
    • MH41 : Arctic partially mixed water column with reduced salinity and medium or long residence time
      
    • MH42 : Atlantic partially mixed water column with reduced salinity and medium or long residence time
      
    • MH43 : Baltic partially mixed water column with reduced salinity and medium or long residence time
      
    • MH44 : Black Sea partially mixed water column with reduced salinity and medium or long residence time
      
    • MH45 : Mediterranean 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
    
    • MH71 : Arctic fronts in reduced salinity water column
      
    • MH72 : Atlantic fronts in reduced salinity water column
      
    • MH73 : Baltic fronts in reduced salinity water column
      
    • MH74 : Black Sea fronts in reduced salinity water column
      
    • MH75 : Mediterranean fronts in reduced salinity water column
      
      • MH751 : Mediterranean ephemeral fronts in reduced salinity water column
        
      • MH752 : Mediterranean seasonal fronts in reduced salinity water column
        
      • MH753 : Mediterranean persistent fronts in reduced salinity water column
        
  • MH8 : Unstratified water column with full salinity
    
    • MH81 : Arctic unstratified water column with full salinity
      
    • MH82 : Atlantic unstratified water column with full salinity
      
      • MH821 : Atlantic euphotic (epipelagic) zone in unstratified full salinity water
        
      • MH822 : Atlantic mesopelagic zone in unstratified full salinity water
        
      • MH823 : Atlantic bathypelagic zone in unstratified full salinity water
        
      • MH824 : Atlantic abyssopelagic zone in unstratified full salinity water
        
    • MH83 : Baltic unstratified water column with full salinity
      
      • MH831 : Baltic euphotic (epipelagic) zone in unstratified full salinity water
        
      • MH832 : Baltic mesopelagic zone in unstratified full salinity water
        
      • MH833 : Baltic bathypelagic zone in unstratified full salinity water
        
    • MH84 : Black Sea unstratified water column with full salinity
      
    • MH85 : Mediterranean unstratified water column with full salinity
      
      • MH851 : Mediterranean euphotic (epipelagic) zone in unstratified full salinity water
        
      • MH852 : Mediterranean mesopelagic zone in unstratified full salinity water
        
      • MH853 : Mediterranean bathypelagic zone in unstratified full salinity water
        
      • MH854 : Mediterranean abyssopelagic zone in unstratified full salinity water
        
  • MH9 : Vertically stratified water column with full salinity
    
  • MHA : Fronts in full salinity water column
    
• MJ : Ice-associated marine habitats
  
  • MJ1 : Sea ice
    
  • MJ2 : Freshwater ice
    
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
• N : Coastal habitats
  
  • N1 : Coastal dunes and sandy shores
    
  • N2 : Coastal shingle
    
  • N3 : Rock cliffs, ledges and shores, including the supralittoral
    
• 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
    
    • U21 : Boreal and arctic siliceous scree and block field
      
    • U22 : Temperate high-mountain siliceous scree
      
    • U23 : Temperate, lowland to montane siliceous scree
      
    • U24 : Mediterranean siliceous scree
      
    • U25 : Boreal and arctic base-rich scree and block field
      
    • U26 : Temperate high-mountain base-rich scree and moraine
      
    • U27 : Temperate, lowland to montane base-rich scree
      
    • U28 : Western Mediterranean base-rich scree
      
      • U281 : Cevenno-Proven
        
      • U282 : Pyrenean calcareous screes
        
      • U283 : Oro-Cantabrian calcareous screes
        
      • U284 : Iberian calciphile fern screes
        
      • U285 : Southern Iberian calcareous screes
        
      • U286 : Central Mediterranean calcareous screes
        
    • U29 : Eastern Mediterranean base-rich scree
      
    • U2A : Crimean base-rich screes
      
  • U3 : Inland cliffs, rock pavements and outcrops
    
  • 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