{Picea rubens), Engelmann spruce {P. engelman- 



• nii), white spruce {P. glauca), Sitka spruce (P. 

 sitchensis), eastern white pine (Pinus strobus), 

 pitch pine {P. rigida), lodgepole pine {P. contorta), 

 longleaf pine {P. palustris), ponderosa pine (P. 

 ponderosa), red pine {P. resinosa), jack pine (P. 

 banksiana), eastern hemlock {Tsuga canadensis), 

 western hemlock (7. heterophylla). Pacific silver 

 fir {Abies amabilis), white fir {A. concolor), and 

 subalpine fir {A. lasiocarpa). In dense stands, these 

 evergreen trees may preclude the establishment of 

 understory vegetation or, in some cases, understo- 

 ry vegetation is also FACU species. Since these 

 plant communities are usually found on nonwet- 

 lands, the ones established in wetland areas may be 

 difficult to recognize at first glance. The landscape 

 position of the evergreen forested areas such as 

 depressions, drainageways, bottomlands, flats in 

 sloping terrain, and seepage slopes, should be con- 

 sidered because it often provides good clues to the 

 likelihood of wetland. Soils also should be exam- 

 ined in these situations. For identification, follow 

 procedures for FACU-dominated wetlands 

 described above. 



3) Wetlands on glacial till - Sloping wetlands 

 occur in glaciated areas where thin soils cover rela- 



• tively impermeable glacial till or where layers of 

 glacial till have different hydraulic conditions that 

 permit groundwater seepage. Such areas are sel- 

 dom, if ever, flooded, but downslope groundwater 

 movement keeps the soils saturated for a sufficient 

 portion of the growing season to produce anaerobic 

 and reducing soil conditions. This promotes devel- 

 opment of hydric soils and hydrophytic vegetation. 

 Indicators of wetland hydrology may be lacking 

 during the drier portion of the growing season. 

 Hydric soil indicators also may be lacking because 

 certain areas are so rocky that it is difficult to exam- 

 ine soil characteristics within 18 inches. 



4) Highly variable seasonal wetlands - In many 

 regions (especially in arid and semiarid regions), 

 depressional areas occur that may have indicators 

 of all three wedand criteria during the wetter por- 

 tion of the growing season, but normally lack indi- 

 cators of wetland hydrology and/or hydrophytic 

 vegetation during the drier portion of the growing 

 season. In addition, some of these areas lack field 

 indicators of hydric soil. OBL and FACW plant 

 species normally are dominant during the wetter 

 ponion of the growing season, while FACU and 



• UPL species (usually annuals) may be dominant 

 during the drier ponion of the growing season and 



during and for some time after droughts. Examples 

 of highly variable seasonal wetlands are pothole 

 wedands in the upper Midwest, playa wedands in 

 the Southwest, and vernal pools along the coast of 

 California. Become familiar with the ecology of 

 these and similar types of wedands (see Appendix 

 A for readings). Also, be particularly aware of 

 drought conditions that permit invasion of UPL 

 species (even perennials). 



5) Interdunal swale wetlands - Along the U.S. 

 coastline, seasonally wet swales supporting hydro- 

 phytic vegetation are located within sand dune 

 complexes on barrier islands and beaches. Some of 

 these swales are inundated or saturated to the sur- 

 face for considerable periods during the growing 

 season, while others are wet for only the~early pan 

 of the season. In some cases, swales may be flood- 

 ed irregularly by the tides. These wetlands have 

 sandy soils that generally lack field indicators of 

 hydric soil. In addition, indicators of wetland 

 hydrology may be absent during the drier part of 

 the growing season. Consequently, these wetlands 

 may be difficult to identify. 



6) Vegetated river bars and adjacent flats - 

 Along western streams in arid and semiarid pans of 

 the country, some river bars and flats may be vege- 

 tated by FACU species while others may be colon- 

 ized by wetter species. If these areas are frequently 

 inundated for one or more weeks during the grow- 

 ing season, they are wedands. The soils often do 

 not reflect the characteristic field indicators of 

 hydric soils, however, and thereby pose delinea- 

 tion problems. 



7) Vegetated flats - Vegetated flats are character- 

 ized by a marked seasonal periodicity in plant 

 growth. They are dominated by annual OBL spe- 

 cies, such as wild rice {Zizania aquatica), and/or 

 perennial OBL species, such as spatterdock 

 (Nuphar luteum), that have nonpersistent vegeta- 

 tive parts (i.e., leaves and stems breakdown rapid- 

 ly during the winter, providing no evidence of the 

 plant on the wedand surface at the beginning of the 

 next growing season). During winter and early 

 spring, these areas lack vegetative cover and 

 resemble mud flats; therefore, they do not appear to 

 qualify as wedands. But during the growing sea- 

 son the vegetation becomes increasingly evident, 

 qualifying the area as wetland. In evaluating these 

 areas, which occur both in coastal and interior pans 

 of the country, one must consider the time of year 

 of the field observation and the seasonality of the 



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