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
      
    • MH22 : Atlantic completely mixed water column with reduced salinity
      
      • MH221 : Atlantic completely mixed water column with reduced salinity and short residence time
        
      • MH222 : Atlantic completely mixed water column with reduced salinity and medium residence time
        
      • MH223 : Atlantic completely mixed water column with reduced salinity and long residence time
        
    • 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
      
      • MH421 : Atlantic partially mixed water column with reduced salinity and medium residence time
        
      • MH422 : Atlantic partially mixed water column with reduced salinity and 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
    
    • MH51 : Arctic unstratified water column with reduced salinity
      
      • MH511 : Arctic euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH512 : Arctic mesopelagic zone in unstratified reduced salinity water
        
      • MH513 : Arctic bathypelagic zone in unstratified reduced salinity water
        
      • MH514 : Arctic abyssopelagic zone in unstratified reduced salinity water
        
    • MH52 : Atlantic unstratified water column with reduced salinity
      
    • MH53 : Baltic unstratified water column with reduced salinity
      
    • 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
    
  • MH8 : Unstratified water column with full salinity
    
    • MH81 : Arctic unstratified water column with full salinity
      
    • MH82 : Atlantic unstratified water column with full salinity
      
    • MH83 : Baltic unstratified water column with full salinity
      
    • MH84 : Black Sea unstratified water column with full salinity
      
      • MH841 : Black Sea euphotic (epipelagic) zone in unstratified full salinity water
        
      • MH842 : Black Sea mesopelagic zone in unstratified full salinity water
        
      • MH843 : Black Sea bathypelagic zone in unstratified full salinity water
        
      • MH844 : Black Sea abyssopelagic zone in unstratified full salinity water
        
    • 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
    
    • MH91 : Arctic vertically stratified water column with full salinity
      
    • MH92 : Atlantic vertically stratified water column with full salinity
      
    • MH93 : Baltic vertically stratified water column with full salinity
      
    • MH94 : Black Sea vertically stratified water column with full salinity
      
    • MH95 : Mediterranean 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
      
• MJ : Ice-associated marine habitats
  
• 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
    
  • 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
    
  • 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
    
• V : Vegetated man-made habitats