356 RESEARCH METHODS 



A reliable method of determining maximum forage production 

 and the composition of such a cover in its highest stages of 

 development is by means of protection plots. For purposes of 

 comparison a plot corresponding with that of the protected area 

 may be established on the open or grazed range. A plot t,^ 

 feet on a side, enclosing one-fortieth of an acre, has been found 

 satisfactory. The plot is divided into four equal squares by 

 means of division tapes, the regular sample-plot form as shown 

 in Figure 130 being used. In the upper right-hand corner of 

 each of the four squares is given the density of the vegetation, 

 and, following it, the species occurring on the plot as a whole are 

 recorded and given convenient symbols for charting. The 

 percentages of the respective species which make up the den- 

 sity of the square unit are then recorded, and the palatability 

 of each for cattle and for sheep is noted. The percentage of each 

 species, multiplied by its percentage of palatability for each class 

 of stock, gives the percentage of palatable forage for that species. 

 When the total of the percentage of palatable forage of all 

 species is multiplied by the density of the cover of the unit, the 

 forage-acre factor is derived. In the example given the data 

 are shown only for one of the four units. The forage-acre 

 factor for the entire area is obtained by averaging this factor 

 for the plot as a whole. The vegetation on the unprotected 

 plots is recorded in the same way as in the example given. 



Sample-Plot Dimensions. — In field work generally it is 

 convenient, in the establishment both of square and circular 

 plots, and for other purposes, to know the dimension require- 

 ments for an acre or a fraction thereof. As a guide for the 

 establishment of sample plots and for general pasture-inspection 

 work the following dimensions for an acre or less are given: 



Square Areas 



Feet on a side Ac 



208 .7 



147 6 



104 35 



66.0 



52.17 



46.6 



350 



Feet on a side Acre 



29- 5 = sV 



87 = rh 



75 = sffTj 



43 = TTjff 



6 = TUSH 



67 = 5?75TJ 



3 = ?cff?j 



