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
      
    • MH12 : Atlantic neuston
      
    • 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
      
    • MH32 : Atlantic completely mixed water column with full salinity
      
    • MH33 : Baltic completely mixed water column with full salinity
      
      • MH331 : Baltic completely mixed water column with full salinity and short residence time
        
      • MH332 : Baltic completely mixed water column with full salinity and medium residence time
        
      • MH333 : Baltic completely mixed water column with full salinity and long residence time
        
    • MH34 : Black Sea completely mixed water column with full salinity
      
    • MH35 : Mediterranean 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
    
    • MH61 : Arctic vertically stratified water column with reduced salinity
      
    • MH62 : Atlantic vertically stratified water column with reduced salinity
      
    • MH63 : Baltic vertically stratified water column with reduced salinity
      
    • MH64 : Black Sea vertically stratified water column with reduced salinity
      
      • MH641 : Black Sea water column with ephemeral thermal stratification and reduced salinity
        
      • MH642 : Black Sea water column with seasonal thermal stratification and reduced salinity
        
      • MH643 : Black Sea water column with permanent thermal stratification and reduced salinity
        
      • MH644 : Black Sea water column with ephemeral halocline and reduced salinity
        
      • MH645 : Black Sea water column with seasonal halocline and reduced salinity
        
      • MH646 : Black Sea water column with permanent halocline and reduced salinity
        
      • MH647 : Black Sea water column with ephemeral oxygen stratification and reduced salinity
        
      • MH648 : Black Sea water column with seasonal oxygen stratification and reduced salinity
        
      • MH649 : Black Sea water column with permanent oxygen stratification and reduced salinity
        
    • MH65 : Mediterranean 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
  
  • MJ1 : Sea ice
    
  • MJ2 : Freshwater ice
    
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
• 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
    
    • U11 : Cave
      
      • U111 : Troglobiont vertebrate caves
        
      • U112 : Subtroglophile vertebrate caves
        
      • U113 : Troglobiont invertebrate caves
        
      • U114 : Troglophile invertebrate caves
        
      • U115 : Subtroglophile invertebrate caves
        
      • U116 : Caves without vertebrates or invertebrates
        
      • U117 : Lava tubes
        
        • U1171 : Icelandic lava tubes
          
        • U1172 : Macaronesian lava tubes
          
        • U1173 : Tethyan lava tubes
          
    • U12 : Disused underground mines and tunnels
      
  • 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