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
      
    • 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
      
      • MH521 : Atlantic euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH522 : Atlantic mesopelagic zone in unstratified reduced salinity water
        
      • MH523 : Atlantic bathypelagic zone in unstratified reduced salinity water
        
      • MH524 : Atlantic abyssopelagic zone in unstratified reduced salinity water
        
    • 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
    
    • 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
    
  • 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
  
• 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
    
  • 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
      
    • 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