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Federal Register / Vol. 56. No. 157 / Wednesday, August 14. 1991 / Proposed Rules 



Hydric Soils Derived From Low Chroma 

 Parent Materials 



Soils derived from slate and phyllite 

 produce low chroma colors due to this 

 parent material. In southern New 

 England, nonhydric soils having 

 predominantly low chroma colors 

 include the following series: Newrport, 

 Nassau, Dutchess, Bemardston, 

 Piltstowrn, Dummerston, Taconic. 

 Macomber, Lakesboro. and Fullan. A 

 few series derived from these materials 

 are hydric. including Stissing, Brayton, 

 and Mansfield, with the first two 

 including nonhydric members as well. 

 Due to the difficulty of using soil colors 

 as indicators of wetness, more weight 

 must be placed on vegetation and 

 hydrology. 



Wetlands That Are Exceptions to the 

 Three Criteria 



There are areas that meet the 

 definition of wetlands but are 

 exceptions to the three mandatory 

 wetland criteria. These exceptions 

 include widely recognized wetlands that 

 fail to meet the weUand hydrology 

 criterion (i.e.. playa lakes, vernal pools, 

 prairie potholes and pocosins which are 

 iniindated and/or saturated at the 

 surface for 7 or more consecutive days 

 during the growing season) and the three 

 specific wetland types that fail to meet 

 the hydrophytic vegetation criterion (i.e.. 

 wetlands that meet the wetland 

 hydrology and hydric soils criteria but 

 are dominated by facultative upland 

 plants, i.e.. Eastern hemlock swamps, 

 white pine bogs, and tamarack swamps). 

 Such areas are wetlands only if they 

 meet one of the descriptions of 

 exceptions to the three criteria provided 

 below. Additional information on some 

 of these exceptions is provided in 

 appendix 5. Other circumstances that 

 warrant special consideration are 

 addressed in this meinual In the 

 "Atypical Hydric Soils" discussion, and 

 the "Problem Area Wetlands" section. 



Pocosins 



The pocosin wetlands of the 

 Southeast contain broadleaved 

 evergreen shrub bogs. Such bogs 

 typically occur in areas characterized by 

 highly organic soils and long 

 hydroperiods during which inundation 

 may but does not always occur. The 

 largest areas of pocosin wetiands occur 

 in the outer Coastal Plain of North 

 Carolina. Although early setUers used 

 the term to depict a variety of swamp 

 vegetation types, pocosin weUands 

 usually are described as marshy or 

 boggy shrub areas or flatwoods wiHi 

 poor drainage where peaty soils 

 typically support scattered pines and a 



dense growth of shrubs, mostly 

 evergreen (Sharitz and Gibbons 1982). 

 Hydrology of pocosins may not be 

 readily apparent due to the thick 

 underlying peaty soils that may dry out 

 rapidly after the early part of the 

 growing season due to 

 evapotranspiration. This, in addition to 

 the strong colloidal bonding between 

 water and organic matter in the soil may 

 make it difficult to squeeze or shake 

 water from the surface soil. Thus, other 

 indicators should be used to identify 

 wetland hydrology in pocosins. Located 

 on the Coastal Plain, pocosins perform 

 important aquatic functions such as 

 storing rainwater and regulating its 

 discharge into nearby estuaries where 

 aquatic life is affected by fluctuations in 

 streamflow and salinity. Pocosins also 

 function to stabilize nutrients, reducing 

 the potential for nutrient overloading in 

 nearby estuaries. 



Playas 



Playas occur in many arid and 

 semiarid regions of the world. Although 

 occurring throughout much of the 

 western United States, they are 

 concentrated in the southern Great 

 Plains as either ephemeral or permanent 

 lakes or weUands. The topography of 

 most playa regions is flat to genUy 

 rolling and generally devoid of drainage. 

 Playa basins collect water primarily in 

 two peak periods — May and 

 September — as a result of regional 

 convectional storms. Wetiand hydrology 

 is best characterized by examining 

 hydrological indicators over a multi-year 

 period. Playa basins may have a dense 

 cover of annual or perennial vegetation 

 or may be barren, depending on the 

 timing and other factors such as 

 precipitation and irrigational runoff. As 

 with potholes, the process of aimual 

 drsdng in playas enables the invasion of 

 FAG, FACU, and UPL plants during dry 

 periods which may persist into other 

 seasons. Playas typically are important 

 waterfowl habitat. Additional 

 information to assist in playa weUand 

 identification is in appendix 5. 



Prairie Potholes 



Prairie potholes are glacially-formed 

 depressional weUands located in the 

 north central United States and southern 

 Canada. Many prairie potholes are 

 seasonally dry but fill with snovraielt 

 and rain early in the grov^dng season. 

 This is because average precipitation is 

 far too sparse to meet the demands of 

 evaporation and as a result, some 

 potholes are dry for a significant portion 

 of the year. The process of annual 

 drying in potholes enables the invasion 

 of FAC, FACU, or UPL plant species 

 during dry periods which may persist 



into wet seasons. Nevertheless, a 

 variety of vegetation characteristic of a 

 freshwater marsh can exist in a prairie 

 pothole with submergent and Ooating 

 plants in deeper water, bulrushes and 

 cattails closer to shore, and sedges 

 located toward the upland. The 

 drastically fluctuating climate and 

 alteration for farming have resulted in 

 highly disturbed conditions that make 

 wetiand identification difficult. Potholes 

 are typically known for supporting an 

 abundance of resident and migratory 

 waterfowl. Additional information to 

 assist in prairie potholes wetiand 

 identification is in appendix 5. 



Vernal Pools 



Vernal pools are natural wetiands are 

 depressional wetiands that are covered 

 by shallow water for variable periods 

 from winter to spring, but may be 

 completely dry at the surface for most of 

 the summer and fall. They hold water 

 long enough to allow some aquatic 

 organisms (e.g., salamanders and frogs) 

 to grow and reproduce (complete their 

 life cycles), but not long enough to 

 permit the development of a typical 

 pond or marsh ecosystem. Since vernal 

 pools vary considerably in depth and 

 duration of both from year to year, 

 wdthin a year, or between different 

 pools, plant composition is quite 

 dynamic. Depending on the seasonal 

 phase of the pool, plants can range from 

 OBL aquatic plants to FAC and FACU 

 species. Additional information to assist 

 in vernal pool wetiand identification is 

 in appendix 5. 



List of Special Wetlands That Fail the 

 Hydrophytic Vegetation Criterion 



Some wetiands demonstrate a 

 prevalence of wetiand plant species that 

 are more typically found in uplands. 

 This usually occurs as a result of the 

 adaptabUity of the species to saturated 

 soil conditions. Wetiand-adapted 

 populations or ecotypes of species that 

 more frequentiy occiir in uplands occur 

 in a wide variety of species (Tiner 

 1991). — Recognizable wetiand types in 

 which this phenomenon occurs are 

 listed below. These areas must meet the 

 wetiand hydrology and hydric soils 

 criteria. 

 White Pine Bogs of Uie Northeast and 



Northern Midwest 

 Eastern Hemlock Swamps and Bogs in 



the Northeast 

 Tamarack Bogs 



Part in. Standard Methods for 

 Identification and Delineation of 

 Wetlands 



Four basic approaches for identifying 

 and delineating wetiands have been 



