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
    
  • 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
      
    • MH54 : Black Sea unstratified water column with reduced salinity
      
    • MH55 : Mediterranean unstratified water column with reduced salinity
      
      • MH551 : Mediterranean euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH552 : Mediterranean mesopelagic zone in unstratified reduced salinity water
        
      • MH553 : Mediterranean bathypelagic zone in unstratified reduced salinity water
        
      • MH554 : Mediterranean abyssopelagic zone in unstratified reduced salinity water
        
  • 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
      
    • MH65 : Mediterranean 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
      
    • MH85 : Mediterranean 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
  
  • S1 : Tundra
    
  • S2 : Arctic, alpine and subalpine scrub
    
  • S3 : Temperate and mediterranean-montane scrub
    
  • S4 : Temperate shrub heathland
    
  • S5 : Maquis, arborescent matorral and thermo-Mediterranean scrub
    
  • S6 : Garrigue
    
  • S7 : Spiny Mediterranean heaths (phrygana, hedgehog-heaths and related coastal cliff vegetation)
    
  • S8 : Thermo-Atlantic xerophytic scrub
    
  • S9 : Riverine and fen scrubs
    
• 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
        
    • U12 : Disused underground mines and tunnels
      
  • U2 : Screes
    
  • U3 : Inland cliffs, rock pavements and outcrops
    
  • U4 : Snow or ice-dominated habitats
    
    • U41 : Snow pack
      
    • U42 : Ice cap and glacier
      
    • U43 : Rock glacier and unvegetated ice-dominated moraine
      
  • U5 : Miscellaneous inland habitats usually with very sparse or no vegetation
    
  • U6 : Recent volcanic features
    
• V : Vegetated man-made habitats