able to survive saturated soil conditions (i.e., a re- 

 ducing environment) because they can transport ox- 

 ygen to their root zone. Look for iron oxide concre- 

 tions (orangish or reddish brown in color) forming 

 along the channels of living roots and rhizomes as 

 evidence of soil saturation (anaerobic conditions) 

 for a significant period during the growing season. 



4) Water marks - Water marks are found most 

 commonly on woody vegetation but may also be 

 observed on other vegetation. They often occur as 

 stains on bark or other fixed objects (e.g., bridge 

 pillars, buildings, and fences). When several water 

 marks are present, the highest usually reflects the 

 maximum extent of recent inundation. 



5) Drift lines - This indicator is typically found 

 adjacent to streams or other sources of water flow 

 in wetlands and often occurs in tidal marshes. Evi- 

 dence consists of deposition of debris in a line on 

 the wetland surface or debris entangled in above- 

 ground vegetation or other fixed objects. Debris 

 usually consists of remnants of vegetation (branch- 

 es, stems, and leaves), sediment, litter, and other 

 water-borne materials deposited more or less paral- 

 lel to the direction of water flow. Drift lines provide 

 an indication of the minimum portion of the area in- 

 undated during a flooding event; the maximum lev- 

 el of inundation is generally at a higher elevation 

 than that indicated by a drift line. 



6) Water-borne sediment deposits - Plants and 

 other vertical objects often have thin layers, coat- 

 ings, or depositions of mineral or organic matter on 

 them after inundation. This evidence may remain 

 for a considerable period before it is removed by 

 precipitation or subsequent inundation. Sediment 

 deposition on vegetation and other objects provides 

 an indication of the minimum inundation level. 

 When sediments are primarily organic (e.g., fine 

 organic material and algae), the detritus may be- 

 come encrusted on or slightly above the soU siirface 

 after dewatering occurs. 



7) Water-stained leaves - Forested wetlands 

 that are inundated earlier in the year will frequently 

 have water-stained leaves on the forest floor. These 

 leaves are generally grayish or blackish in appear- 

 ance, darkened from being underwater for signifi- 

 cant periods. 



8) Surface scoured areas - Surface scouring oc- 

 curs along floodplains where overbank flooding 

 erodes sediments (e.g., at the bases of trees). The 



absence of leaf litter from the soil surface is also 

 sometimes an indication of surface scouring. Fo- 

 rested wetlands that contain standing waters for rel- 

 atively long duration will occasionally have areas of 

 bare or essentially bare soil, sometimes associated 

 with local depressions. 



9) Wetland drainage patterns - Many wetlands 

 (e.g., tidal marshes and floodplain wedands) have 

 characteristic meandering or braided drainage pat- 

 terns that are readily recognized in the field or on 

 aerial photographs and occasionally on topographic 

 maps. {CAUTION: Drainage patterns also occur in 

 upland areas after periods of considerable precipita- 

 tion; therefore, topographic position also must be 

 considered when applying this indicator.) 



10) Morphological plant adaptations - Many 

 plants growing in wetlands have developed mor- 

 phological adaptations in response to inundation or 

 soil saturation. Examples include pneumatophores, 

 buttressed tree trunks, multiple trunks, adventitious 

 roots, shallow root systems, floating stems, float- 

 ing leaves, polymorphic leaves, hypertrophied len- 

 ticels, inflated leaves, stems or roots, and aeren- 

 chyma (air-filled) dssue in roots and stems (see 

 Table 1 for examples). As long as there is no evi- 

 dence of significant hydrologic modificadon, these 4^ 

 adaptations can be used as hydrologic indicators. 

 Moreover, when these features are observed in 

 young plants, they provide good evidence that re- 

 cent wetland hydrology exists. {Note: While some 

 people may consider these morphological adapta- 

 dons as indicators of hydrophytic vegetation, for 

 purposes of this manual, they are treated as indica- 

 tors of wetland hydrology because they typically 

 develop in response to permanent or periodic inun- 

 dation or soil saturation.) 



1 1 ) Hydric soil characteristics - In the absence 

 of the above indicators, if an area meets the field in- 

 dicators for hydric soils and there is no indication 

 of significant hydrologic modification, then it can 

 be assumed that the area meets the wetiand hydrol- 

 ogy criterion. If the area has been significantly dis- 

 turbed hydrologically, refer to the section on dis- 

 turbed areas (p. 50). {CAUTION: Listing of a soil 

 on the NTCHS list of hydric soils does not neces- 

 sarily mean the wedand hydrology cnterion is met, 

 nor does exclusion of a soil from the list demon- 

 strate that the wetland hydrology criterion has not 

 been met. However, soils on the NTCHS list rep- 

 resent those soils which typically meet the wetland ^^ 

 hydrology criterion, unless effectively drained or \ 

 otherwise altered.) 



