CHOICE OF SPECIES IN ARTIFICIAL REGENERATION 17 



the site factors of the region where the regeneration is under- 

 taken and the silvical requirements of the species tried. Because 

 of the expense and labor involved in measuring the site factors 

 and our very imperfect knowledge off the habitat requirements of 

 the different species, it is usually very difficult in practice to arrive 

 at an accurate judgment. 



2. SEEDING AND PLANTING TO REALIZE THE OBJECT IN VIEW 



In the comparison of the qualities of various species for use on 

 a particular site, it is comparatively easy to arrive at a reason- 

 ably accurate judgment of the relative value of the product, the 

 cost of reproduction, and whether the species will meet market 

 requirements and be capable of economic handling in logging 

 operations. It is far more difficult to arrive at a safe judgment 

 of the silvicultural value of the several species and to what 

 extent their requirements for growth and development are fully 

 met by the climate, soil, and other site factors. When we select 

 species for seeding and planting with the expectation that the 

 resulting stand will most fully realize the object in view, whether 

 it be for the production of a particular product or for the pro- 

 tection and improvement of the soil, we must usually depend upon 

 the best species indigenous to the immediate vicinity. Before at- 

 tempting to make our choice, a careful examination should be 

 made of all the species growing on the site and on similar sites in 

 the vicinity. The evidence of growing timber is much more re- 

 liable than a judgment of correlation between the site factors and 

 the silvical requirements of a particular species. When afforest- 

 ation is necessary, as in semi-arid and prairie regions, it is often 

 more difficult to arrive at a safe selection, because we are forced 

 in our selection to depend chiefly upon our knowledge of the site 

 factors and the silvical requirements of the various species. 



3. THE USE OF EXOTICS AND SPECIES FROM 

 REMOTE REGIONS 



In artificial reproduction, exotics and species from widely 

 different regions are not infrequently selected for use in both 

 seeding and planting to the neglect of the more useful species of 

 the locality. From the standpoint of economic results, this prac- 

 tice is usually very hazardous. We cannot hope to modify ap- 

 preciably the requirements of a species by forcing it to grow under 



