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
    
    • MH11 : Arctic neuston
      
      • MH111 : Arctic temporary neuston layer
        
      • MH112 : Arctic permanent neuston layer
        
    • MH12 : Atlantic neuston
      
      • MH121 : Atlantic temporary neuston layer
        
      • MH122 : Atlantic permanent neuston layer
        
    • MH13 : Baltic neuston
      
    • MH14 : Black Sea neuston
      
    • MH15 : Mediterranean neuston
      
  • MH2 : Completely mixed water column with reduced salinity
    
  • MH3 : Completely mixed water column with full salinity
    
    • MH31 : Arctic completely mixed water column with full salinity
      
      • MH311 : Arctic completely mixed water column with full salinity and short residence time
        
      • MH312 : Arctic completely mixed water column with full salinity and medium residence time
        
      • MH313 : Arctic completely mixed water column with full salinity and long residence time
        
    • MH32 : Atlantic completely mixed water column with full salinity
      
    • MH33 : Baltic completely mixed water column with full salinity
      
    • MH34 : Black Sea completely mixed water column with full salinity
      
    • MH35 : Mediterranean completely mixed water column with full salinity
      
      • MH351 : Mediterranean completely mixed water column with full salinity and short residence time
        
      • MH352 : Mediterranean completely mixed water column with full salinity and medium residence time
        
      • MH353 : Mediterranean completely mixed water column with full salinity and long residence time
        
  • MH4 : Partially mixed water column with reduced salinity and medium or long residence time
    
  • MH5 : Unstratified water column with reduced salinity
    
    • MH51 : Arctic unstratified water column with reduced salinity
      
    • MH52 : Atlantic unstratified water column with reduced salinity
      
    • MH53 : Baltic unstratified water column with reduced salinity
      
      • MH531 : Baltic euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH532 : Baltic mesopelagic zone in unstratified reduced salinity water
        
      • MH533 : Baltic bathypelagic zone in unstratified reduced salinity water
        
      • MH534 : Baltic abyssopelagic zone in unstratified reduced salinity water
        
    • MH54 : Black Sea unstratified water column with reduced salinity
      
    • MH55 : Mediterranean 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
      
  • MH8 : Unstratified water column with full salinity
    
  • MH9 : Vertically stratified water column with full salinity
    
  • MHA : Fronts in full salinity water column
    
    • MHA1 : Arctic fronts in full salinity water column
      
    • MHA2 : Atlantic fronts in full salinity water column
      
    • MHA3 : Baltic fronts in full salinity water column
      
    • MHA4 : Black Sea fronts in full salinity water column
      
    • MHA5 : Mediterranean fronts in full salinity water column
      
      • MHA51 : Mediterranean ephemeral fronts in full salinity water column
        
      • MHA52 : Mediterranean seasonal fronts in full salinity water column
        
      • MHA53 : Mediterranean persistent fronts in full salinity water column
        
• MJ : Ice-associated marine habitats
  
  • MJ1 : Sea ice
    
  • MJ2 : Freshwater ice
    
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
    • MJ41 : Arctic under-ice habitat
      
    • MJ42 : Baltic under-ice habitat
      
• 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
    
  • 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