HOME
wetlands defined
wetland delineation
-introduction
-hydrophytic vegetation
-hydrophytic plant
 classifications

-test your knowledge

 
hydrophytic plants
hydrophytic plant adaptations
wetland hydrology
wetland soils
delineation procedures
wetland mitigation
literature and links
 

 

Identification, delineation and mitigation

Wetland delineation

Hydrophytic plant classifications page 3 of 3
   
Plant species in the United States have been classified according to their wetland indicator status, which reflects their frequency of occurrence in wetlands under natural conditions. The five indicator-status categories are:
Indicator
Category

Indicator Symbol
 

Definition
Obligate Wetland Plants OBL Plants that occur almost always (estimated probability >99%) in wetlands under natural conditions, but which may also occur rarely (estimated probability <1%) in non-wetlands. Examples: smooth cordgrass, bald cypress

 
Facultative Wetland Plants FACW Plants that occur usually (estimated probability >67% to 99%) in wetlands, but also occur (estimated probability 1% to 33% in non-wetlands). Examples: green ash, Red-osier dogwood
 
Facultative Plants FAC Plants with a similar likelihood (estimated probability 33% to 67%) of occurring in both wetlands and non-wetlands. Examples: honey locust, common greenbrier
 
Facultative Upland Plants FACU Plants that occur sometimes (estimated probability 1% to <33%) in wetlands, but occur more often (estimated probability >67% to 99%) in non-wetlands. Examples: red oak, tall cinquefoil
 
Obligate Upland Plants UPL Plants that occur rarely (estimated probability <1%) in wetlands, but occur almost always (estimated probability >99%) in wetlands under natural conditions. Examples: shortleaf pine, soft brome
 

The facultative categories may have modifiers of plus (+) or minus (-), respectively, to indicate a speciesí affinity for the wetter or drier ends of its category.

A community is hydrophyticmore information if more than 50% of dominant species (all species combined into one list) are OBL, FACW, or FAC. Species rated FAC- do not count in this tally. Instead, they are counted among the FACU and UPL plants.

click here to test your knowledge
  previous

back to top