(d) Repeat (b) and (c) as required by 

 the sampling scheme. 



(e) Construct a species area curve (see 

 example, Appendix C) for the plot to determine 

 whether the number of quadrats sampled sufficient- 

 ly represent the vegetation in the stratum; the num- 

 ber of samples necessary corresponds to the point 

 at which the curve levels off horizontally; if neces- 

 sary, sample additional quadrats within the plot 

 until the curve levels off. 



(f) For each plant species sampled, deter- 

 mine the average percent areal cover by summing 

 the percent area! cover for all sample quadrats with- 

 in the plot and dividing by the total number of 

 quadrats (see example. Appendix C). Proceed to 

 substep B below. 



(2) Fixed interval sampling approach: 



(a) Place one (1) - 40" x 40" sample 

 quadrat centered on the transect 

 point. 



(b) Determine percent areal coverage for 

 each species. Proceed to substep B 

 below. 



B) Rank plant species by their average percent 

 areal cover, beginning with the most abundant spe- 

 cies. 



C) Sum the percent cover (fixed interval sam- 

 pling approach) or average- percent cover (plant 

 community transect sampling approach). 



D) Determine the dominance threshold number - 

 the number at which 50 percent of the total domi- 

 nance measure (i.e., total cover) for the stratum is 

 represented by one or more plant species when 

 ranked in descending order of abundance (i.e., 

 firom most to least abundant). 



E) Sum the cover values for the ranked plant 

 species beginning with the most abundant until the 

 dominance threshold number is immediately 

 exceeded; these species contributing to surpassing 

 the threshold number are considered dominants, 

 plus any additional species representing 20 percent 

 or more of the total cover of the stratum; denote 

 dominant species with an asterisk on the appropri- 

 ate data form. 



F) Designate the indicator status of each domi- 

 nant. 



2) Bryophyte stratum (mosses, homed liverworts, 

 and true liverworts): Bryophytes may be sampled 

 as a separate stratum in certain wedands, such as 

 shrub bogs, moss-lichen wedands, and the wetter 

 wooded swamps, where they are abundant and rep- 

 resent an important component of the plant commu- 

 nity. If treated as a separate stratum, follow the 

 same procedures as listed for herb stratum. In 

 many wetlands, however, bryophytes are not abun- 

 dant and should be included as part of the herb stra- 

 tum. 



3) Shrub stratum (woody plants usually between 3 

 and 20 feet tall, including multi-stemmed, bushy 

 shrubs and small trees below 20 feet): 



A) Determine the percent areal cover of shrub 

 species within the entire plot by walking through 

 the plot, lisring all shrub species and estimating the 

 percent areal cover of each species. 



B) Indicate the appropriate cover class (T and 1 

 through 7) and its corresponding midpoints (shown 

 in parentheses) for each species: T = <1% cover 

 (None); 1 = 1-5% (3.0); 2 = 6-15% (10.5); 3 = 16- 

 25% (20.5); 4 = 26-50% (38.0); 5 = 51-75% 

 (63.0); 6 = 76-95% (85.5); 7 = 96-100% (98.0). 



C) Rank shrub species according to their mid- 

 points, from highest to lowest midpoint; 



D) Sum the midpoint values of all shrub spe- 

 cies. 



E) Determine the dominance threshold number - 

 the number at which 50 percent of the total domi- 

 nance measure (i.e., cover class midpoints) for the 

 stratum is represented by one or more plant species 

 when ranked in descending order of abundance 

 (i.e., from most to least abundant). 



F) Sum the midpoint values for the ranked 

 shrub species, beginning with the most abundant, 

 until the dominance threshold number is immediate- 

 ly exceeded; these species are considered domi- 

 nants, plus any additional species representing 20 

 percent or more of the total midpoint values of the 

 stratum; identify dominant species (e.g., with an 

 asterisk) on the appropriate data form. 



43 



