approach of the three recommended types of onsite 

 determinations. It is usually reserved for highly 

 complicated and/or large project areas, and/or when 

 the determination requires rigorous documentation. 

 Due to the latter situation, this type of onsite deter- 

 mination may be used for areas of any size. 



4.16. In applying this method, a team of experts, 

 including a wetland ecologist and a qualified soil 

 scientist, is often needed, especially when rigorous 

 documentation of plants and soils are required. It 

 is, possible, however, for a highly trained wetland 

 boundary specialist to singly apply this method. 



4.17. Two alternative approaches of the compre- 

 hensive onsite determination method are presented: 

 (1) quadrat sampling procedure and (2) point inter- 

 cept sampling procedure. The former approach 

 establishes quadrats or sampling areas in the project 

 site along transects, while the latter approach 

 involves a frequency analysis of vegetation at sam- 

 pling points along transects. The point intercept 

 sampling procedure requires that the limits of 

 hydric soils be established prior to evaluating the 

 vegetation. In many cases, soil maps are available 

 to meet this requirement, but in other cases a quali- 

 fied soil scientist may need to inventory the soils 

 before applying this method. The quadrat sampling 

 procedure, which involves identifying plant com- 

 munities along transects and analyzing vegetation, 

 soils, and hydrology within sample plots (quad- 

 rats), may be the preferred approach when soil 

 maps are unavailable or the individual is more 

 familiar with plant identification. 



Quadrat Sampling Procedure 



4.18. Prior to implementing this determination 

 procedure, read the sections of this manual that dis- 

 cuss disturbed area and problem area wetland deter- 

 mination procedures (pp. 50-59); this information 

 is often relevant to project areas requiring a com- 

 prehensive determination. 



Step \. Locate the limits of the project area 

 in the field. Previously, the project boundary 

 should have been determined on aerial photos or 

 maps. Now appropriate ground reference points 

 need to be located to ensure that sampling will be 

 conducted in the proper area. Proceed to Step 2. 



Step 2. Stratify the project area into different 

 plant community types. Delineate the locations of 

 these types on aerial photos or base maps and label 

 each community with an appropriate name. (CAU- 

 TION: In highly variable terrain, such as ridge and 

 swale complexes, be sure to stratify properly to 

 ensure best results.) In evaluating the subject area, 

 were any significantly disturbed areas observed? If 

 YES, identify their limits for they should be evalu- 

 ated separately for wetiand determination purposes 

 (usually after evaluating undisturbed areas). Refer 

 to the section on disturbed areas (p. 50) to evaluate 

 the altered characteristic(s) (i.e., vegetation, soils, 

 and/or hydrology); then return to this method to 

 continue evaluating the characteristics not altered. 

 Keep in mind that if at any time during this determi- 

 nation, it is found that one or more or these three 

 characteristics have been significantly altered, the 

 disturbed areas wetland determination procedures 

 should be followed. If the area is not significantly 

 disturbed, proceed to Step 3. 



Step 3. Establish a baseline for locating sam- 

 pling transects. Select as a baseline one project 

 boundary or a conspicuous feature, such as a road, 

 in the project area. The baseline ideally should be 

 more or less parallel to the major watercourse 

 through the area, if present, or perpendicular to the 

 hydrologic gradient (see Figure 5). Determine the 

 approximate baseline length and record its origin, 

 length, and compass heading in a field notebook. 

 When a limited number of transects are planned, a 

 baseline may not be necessary provided there are 

 sufficient fixed points (e.g., buildings, walls, and 

 fences) to serve as starting points for the transects. 

 Proceed to Step 4. 



Step 4. Determine the required number and 

 position of transects. The number of transects 

 necessary to adequately characterize the site will 

 vary due to the area's size and complexity of habi- 

 tats. In general, it is best to divide the baseline into 

 a number of equal segments and randomly select a 

 point within each segment to begin a transect (see 

 Figure 5). 



Use the following as a guide to determine the 

 appropriate number of baseline segments: 



40 



