360 FOREST INDICATORS. 



ture content of the different sites and therefore for prognosticating the kind 

 of timber the site can best support. The native shrubs and herbaceous 

 vegetation, since they are not merely forerunners of the forest type that will 

 eventually develop on a given site, but are also associates and are characteris- 

 tic of different types as their typical undergrowth, are useful in deciding upon 

 the species to plant. This is true not only where the original forest has en- 

 tirely disappeared, but also on sites where there are still some traces of the 

 original stand but which, because of the change in the physical condition of 

 the site brought about by clear-cutting or burning, may better support a 

 species which naturally grows at a somewhat lower elevation. 



"For the purpose of artificial reforestation, Ephraim Canyon may be di- 

 vided into five vegetation belts. The upper and lower limits of these vegeta- 

 tion belts vajy, of course, on the southern and northern exposures; on the 

 southern slopes the upper limits of each vegetation belt will extend to a higher 

 elevation than on the northerly slopes, but wherever a certain vegetation is 

 found it may be indicative of one or another natural timber belt, irrespective 

 of the altitude or exposure. These five belts are as follows: (1) the lower 

 timberless belt; (2) the yellow-pine belt; (3) the Douglas-fir belt; (4) the 

 Engelmann-spruce belt; and (5) the upper timberless belt." 



The indicators of the various zones are shown in figure 25. 

 Tillotson (1917:53) has pointed out the importance of indicators in the 

 selection of planting sites (plate 91) : 



"The suitabihty of an area is very strongly indicated by the natural growth 

 present. This is a pretty fair criterion of the quahty of the site, and it points 

 out the species which are most hkely to succeed either those which naturally 

 occupy the area or others whose demands upon soil and chmate are quite 

 similar. A heavy growth of trees on similar adjacent sites will indicate that 

 the area is quite probably suitable for sowing or planting; while a sparse growth 

 of a drought-resistant species of tree on such sites will indicate that the area is 

 only suited to reforesting' with very drought-resistant species and that even 

 then success will be uncertain." 



He has also given a detailed summary of the planting indicators for the 

 various regions and the most important species of the West. The nature and 

 importance of his account may be gained from the following extract, which 

 gives the indicators for Utah and southern Idaho: 



"Western yellow pine in Utah: (1) Burned-over areas in the natural yel- 

 low-pine types; (2) areas covered with brush, mainly of oak, maple, and 

 service berry; (3) areas covered with open stands of scrubby aspen; (4) sage- 

 brush areas. 



"Western yellow pine in southern Idaho: (1) Those sites producing yellow 

 pine naturally; (2) brush areas withjn the limits of yellow pine and adjoining 

 stands of that species; (3) open grassy areas in the neighborhood of timber 

 stands. 



"Douglas fir: (1) Bums within the fir type; (2) sites covered with aspen 

 of moderate density; (3) bums in the Engelmann spmce type; (4) areas 

 covered with bmsh of oak, maple, service berry, cherry, and other deciduous 

 species; (5) open grassland and mountain meadows. The planting of this 

 species naturally centers mainly around the aspen type, particularly in Utah. 

 The last two sites are not considered favorably for planting at present. 



"Engelmann spmce: (1) Bumed-over, non-restocking Engelmann spmce 

 and balsam-fir cuttings; (2) the denser and better stands of aspen occurring 

 at high altitudes; (3) lodgepole-pine bums. 



