Federal Register / Vol. 56, No. 157 / Wednesday. August 14, 1991 / Proposed Rules 40465 



(dominants) exceeds that of FACU and 

 UPL species (dominants), the area is 

 considered wetland and the wetland- 

 nonwetland boundary is the line 

 delineated by the limits of conditions 

 that verify the wedand hydrology 

 criterion. If not, then the point intercept 

 or other sampling procedures should be 

 performed to do a more rigorous 

 analysis of site characteristics. 



Plant Community Assessment Procedure 



Step 1. Scan the entire project area, if 

 possible, or walk, if necessary, and 

 identify plant community types present. 

 In identifying communities, pay 

 particular attention to changes in 

 elevation throughout the site. 



CautioD: In highly variable sites, such as 

 ridge and swale complexes, be sure to 

 stratify properly, i.e., divide the site into 

 homogeneous landforms to evaluate each 

 landform separately. 



If possible, sketch the approximate 

 location of each plant community on a 

 base map, an aerial photograph of the 

 project area, or a county soil survey map 

 and label each community with an 

 appropriate name. 



Note: For large homogeneous wetlands, 

 especially marshes dominated by herbaceous 

 plants and shrub bogs dominated by low- 

 growing shrubs, it is usually not necessary to 

 walk the entire project area. In these cases, 

 one can often see for long distances and 

 many have organic mucky soils that can be 

 extremely difficult to walk on. Forested 

 areas, however, will usually require a walk 

 through the entire project area. 



In examining the project area, are any 

 significandy disturbed areas observed? 

 If yes, identify their limits for they 

 should be evaluated separately for 

 weUand determination piurpose (usually 

 after evaluating undisturbed areas). 

 Refer to the section on disturbed areas 

 to evaluate the altered characteristic(s) 

 (i.e., vegetation, soils, or hydrology). If 

 appropriate, determine vi/hether weUand 

 regulatory policy exempts the area from 

 Federal regulatory jurisdiction (e.g., 

 regulatory policy on vireUands converted 

 to cropland); then return to this method 

 to continue evaluating characteristics 

 not altered. Keep in mind that if at any 

 time during this determination one or 

 more of these three characteristics are 

 foimd to have been significanUy altered, 

 the disturbed area procedures should be 

 followed. If the area is not significanUy 

 disturbed, proceed to Step 2. 



Step 2. Consider the following: 



(1) Is the area presenUy lacking 

 hydrophytic vegetation or hydrologic 

 indicators due to annual, seasonal or 

 long-term fluctuations in precipitation, 

 surface water, or ground-water levels? 



(2) Are hydrophytic vegetation 

 Indicators lacking due to seasonal 



fluctuations in temperature (e.g., 

 seasonality of plant growth)? 



If the answer to either of these 

 questions is Yes or uncertain, and the 

 area meets the description of one of the 

 exceptions to the three criteria, proceed 

 to the appropriate section of this 

 manual. If the answer to both questions 

 is No, normal conditions are assumed to 

 be present, so proceed to Step 3. 



Note: In some cases, normal climatic 

 conditions, such as snow cover or frozen 

 soils, may prevent an accurate assessment of 

 the wetland criteria; one must use best 

 professional judgement to determine if 

 delaying the wetland delineation is 

 appropriate. 



Step 3. Select representative 

 observation area(3). Select one or more 

 representative observation areas within 

 each community type. A representative 

 observation area is one in which the 

 apparent characteristics (determined 

 visually) best represent characteristics 

 of the entire community. Mark the 

 approximate location of the observation 

 areas on the base map or photo. Proceed 

 to Step 4. 



Step 4. Characterize each plant 

 community in the project area. Within 

 each plant community identified in Step 

 1, visually estimate the dominant plant 

 species for each valid vegetative 

 stratum in the representative 

 observation areas and record them on 

 an appropriate data form. Vegetative 

 strata may include tree, sapling, shrub, 

 herb, woody vine, and bryophyte strata 

 (see glossary for definitions). Make sure 

 the size of the observation area is 

 sufficient to insure a representative 

 assessment of the plant commimity. A 

 separate form must be completed for 

 each plant community identified for 

 wetland determination purposes. After 

 identifying domineuits within each 

 vegetative stratum, proceed to Step 5. 



Step 5. Record the indicator status of 

 dominant species in all strata. Indicator 

 status is obtained from the interagency 

 Federal list of plants occurring in 

 weUands for the appropriate geographic 

 region. Record indicator status for all 

 dominant plant species on a data form. 

 Proceed to Step 6. 



Step 8. Determine whether the 

 hydrophytic vegetation criterion is met. 

 Complete the vegetation section of the 

 data form. Portions of the project area 

 failing this test are usually not weUands, 

 although under certain ciraunstances 

 they may have weUand hydrology and 

 therefore be weUand (see list of 

 exceptions). Proceed to Step 7. 



Step 7. Determine whether the hydric 

 soil criterion is met. Locate the 

 observation area on a county soil survey 

 map, if possible, and determine the soil 

 map unit delineation for the area. Using 



a soil auger, probe, or spade, make a 

 hole at least 18 inches deep at the 

 representative location in each plant 

 community type. Examine soil 

 characteristics and compare i| possible 

 to soil descriptions in the county soil 

 survey report or classify to Subgroup 

 following "Soil Taxonomy" (often 

 requires digging a deeper hole), or look 

 for regional indicators of significant soil 

 saturation. If soil has been plowed or 

 otherwise altered, which may have 

 eliminated these indicators, proceed to 

 the section on disturbed areas. Complete 

 the soils section on the appropriate data 

 sheet and proceed to Step 8 if conditions 

 satisfy the hydric soil criterion. Areas 

 having soils that do not meet the hydric 

 soil criterion are nonweUands. 



(Caution: Become familiar with problematic 

 hydric soils that do not possess good hydric 

 field indicators, such as red parent material 

 soils, some sandy soils, and some floodplain 

 soils, so that these hydric soils are not 

 misidentified as nonhydric soils. See 

 discussion under "Atypical Hydric Soils".) 



Step 8. Determine whether the 

 weUand hydrology criterion is met. 

 Record observations and complete the 

 hydrology section on the appropriate 

 data form. If the weUand hydrology 

 criterion is met, proceed to Step 9. If the 

 weUand hydrology criterion is not met, 

 the area is nonweUand. 



(Caution: Certain exceptions to the three 

 criteria may not meet the hydrology criterion; 

 see discussion of these areas.) 



Step 9. Make the weUand 

 determination. Examine data forms for 

 each plant commimity identified in the 

 project area. Each community meeting 

 the hydrophytic vegetation, hydric sod. 

 and weUand hydrology criteria is 

 considered weUand. If all communities 

 meet these three criteria, then the entire 

 project area is a weUand. If only a 

 portion of the project area is weUand, 

 then the weUand-nonweUand boundary 

 must be established. Proceed to Step 10. 



Step 10. Determine the weUfind- 

 nonweUand boundary. Where a base 

 map or armolated photo was prepared, 

 mark each plant community type on the 

 map or photo wiUi a "W" if weUand or 

 an "N" if nonweUand. Combine all "W" 

 types into a single mapping unit, if 

 possible, and aU "N" types into another 

 mapping unit On the map or photo, the 

 weUand boimdary will be represented 

 by the interface of Uiese mapping units. 

 If flagging die boundary on the ground, 

 the boundary is established by 

 determining the limits of the indicators 

 that verify aU these criteria. 



