DENUDED OR DEPOPULATED PLOTS 349 



The same design of sample-plot tapes is used in the listing 

 plan of mapping as for charting. The Hst plot, because of the 

 rapidity with which the mapping is done, is usually made larger 

 than the chart plot, an additional advantage in securing rep- 

 resentative conditions. 



Denuded or Depopulated Plots. — The most rehable means 

 of determining the rate of the invasion and estabHshment of 

 vegetation on badly depleted range is to locate representative 

 sample plots on areas that have been quite or nearly denuded by 

 foraging animals. Artificial depopulation of sample plots has 

 been more or less popular with students of range revegetation 

 in determining the rate of invasion of species. Data as to the 

 rate of the invasion and estabHshment on artificially denuded 

 plots may furnish some information relative to the rate at 

 which lands denuded by grazing may be built up; but the re- 

 sults are not reliable, because of the absence of a highly influen- 

 tial factor, namely, the packing of the soil. The heavy packing 

 of the soil by livestock, especially the tramphng when the soil 

 is wet, has a profound efifect upon revegetation. Accordingly, 

 in the natural reestablishment of the cover on denuded areas 

 those depopulated through excessive or untimely grazing should 

 be selected for study. 



The value of the artificially denuded plot in revegetational 

 work lies chiefly in its use for determining the viabiHty of the 

 seed of native vegetation. Here the meter quadrat is valuable. 

 Following the artificial removal of the vegetation, regular 

 quadrat tapes one meter in length, marked off at decimeter 

 intervals, are laid down; then a seed is placed at each deci- 

 meter interval, and, if desired, also midway between the inter- 

 vals, making 100 or 200 seeds to the quadrat according to the 

 spacing. The following spring the plot tapes are replaced, and 

 the results of the germination recorded. This method of de- 

 termining seed viability is valuable for use on high mountain 

 range where little is known of the temperature requirements 

 and certain other physical stimuh for normal seed germination.^ 



1 Sampson, Arthur W., "The Quadrat Method as Applied to Investigations in 

 Forestry." Forest Club Annual, Univ. of Nebr., Vol. 6, pp. 5, 6, 1915. 



