'0 SAMPLE PLOT STUDIES 



DlKLX'TlONS: • 



A. Parties. — A men. 'I'lic organization of (he work for each man is loft to 



the "Chief of I^irty " designated by the instructor. lie will be marked 

 on the efficiency with which his party carries out the work. Remember 

 that every man should be kept busy. 



B. Equipment Required. 

 1 100-foot steel tape. 



1 surveyor's compass, or 1 angle mirror. 



2 pairs of tree calipers. 

 1 cross-cut saw. 



1 hand axe. 



2 bark scratchers (white carpenter's chalk often answers the purpose 



even better) . 



3 field notebooks (one per man), with blank Forms 1, 2 A, and 3 A, and 



cross-section paper. 



C. Method of Procedure. 



1. Determine the area of the tract. In order to save time assume an 



arbitrary area of 40 acres. 



2. Make a careful examination of the entire tract for the purpose of 



selecting a plot that will represent average conditions. 



3. Carefully lay off a sample plot (i to r& acre will do to illustrate the 



problem). Mark the bovmdaries carefully. 



4. Cafiper all the trees in the sample area at D.B.H. to the nearest inch, 



down to a minimum diameter of 2 inches. Mark each tree calipered, 

 to avoid repetition. For convenience in recording the measurements 

 use a form similar to that used when cruising on the basis of diameters 

 only. (Form 3 A.) 



5. Arrange all data, including the calculated values, in a convenient 



tabular form. 



6. Determine the diameter of the average tree by the formula: 



6ini+52n2+63^i3 4-etc. 

 '' = - N • 



in which 6 = the average basal area of all trees on the plot; 



6i, hi, etc. = basal areas of the ditTerent diameters; 



Ml, n-,, etc. = number of trees of each diameter; 

 A^ = total number of trees on the plot. 

 Use table of basal areas for getting the diameter values of h. 



7. Cut three trees whose diameters fall within 0.5 of an inch of the diam- 



eter of the average tree. Be careful to select trees of average height 

 and crown development. Number the stump of each tree to corre- 

 spond ivith the number of the record sheet so that both may be used for 

 future problems. Record measurements on Form 2 A. 



