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
    
  • 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
    
  • MH5 : 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
    
  • 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
    
• MJ : Ice-associated marine habitats
  
  • MJ1 : Sea ice
    
    • MJ11 : Arctic sea ice
      
      • MJ111 : Seasonal Arctic pack-ice
        
      • MJ112 : Permanent Arctic pack-ice
        
      • MJ113 : Arctic Ice floes
        
    • MJ12 : Baltic sea ice
      
  • MJ2 : Freshwater ice
    
    • MJ21 : Arctic freshwater ice
      
  • MJ3 : Brine channels
    
    • MJ31 : Arctic brine channels
      
      • MJ311 : Arctic brine channels in first year ice
        
      • MJ312 : Brine channels in multi-year ice
        
    • MJ32 : Baltic 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
    
    • R41 : Snow-bed vegetation
      
      • R411 : Boreo-alpine acidocline snow-patch grassland and herb habitats
        
      • R412 : Boreo-alpine calcicline snow-patch grassland and herb habitats
        
      • R413 : Ponto-Caucasian snow-patch grassland
        
      • R414 : Boreo-alpine fern snowbed grassland
        
    • R42 : Boreal and arctic acidophilous alpine grassland
      
    • R43 : Temperate acidophilous alpine grassland
      
    • R44 : Arctic-alpine calcareous grassland
      
    • R45 : Alpine and subalpine calcareous grassland of the Balkans and Apennines
      
  • R5 : Forest fringes and clearings and tall forb stands
    
    • R51 : Thermophilous forest fringe of base-rich soils
      
    • R52 : Forest fringe of acidic nutrient-poor soils
      
    • R53 : Macaronesian thermophilous forest fringe
      
    • R54 : Pteridium aquilinum vegetation
      
    • R55 : Lowland moist or wet tall-herb and fern fringe
      
    • R56 : Montane to subalpine moist or wet tall-herb and fern fringe
      
    • R57 : Herbaceous forest clearing vegetation
      
  • 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
  
• V : Vegetated man-made habitats