THE NORTHERN HARDWOOD FOREST. 35 



growth of centuries, and (2) the advantage of placing the stand on 

 an active, producing, instead of an idle, nonproducing basis. The 

 problem of management then becomes how best to dispose of the old 

 growth so as to secure the most desirable composition of the ensuing 

 stand of young growth. Before making cuttings the species which 

 are to be favored in securing reproduction must be decided upon. 



CHOICE OF SPECIES. 



Wherever possible, a mixture of hardwoods and conifers is desirable. 

 Mixed forests produce heavier yields of better quality, are more 

 effective for watershed protection, and present less risk of total loss 

 from various sources than pure forests. From the standpoint of 

 aggressiveness conifers are not as a rule a menace to the supremacy 

 of hardwoods on fertile soils. To secure natural softwood growth 

 among hardwoods is, in fact, usually a difficult matter, requiring 

 a high degree of technical skill. Red spruce, hemlock, and white 

 pine are the best species to grow among hardwoods. 



Of the hardwoods, white ash, basswood, elms, black birch, yellow 

 birch, and red oak are to be favored when in mixture with the more 

 tolerant beech and sugar maple. Beech is usually the least valuable 

 of the species, commercially, so that where possible it should be 

 eliminated and its place given to better species. Its silvicultural value 

 is high, but so closely resembles that of sugar maple that ordinarily no 

 object is gained in keeping it in stands containing both. Sugar maple 

 is the easiest of the intensive species to perpetuate in management. 

 Its reproductive aggressiveness is such that in many regions it will 

 . probably be necessary to discourage it in favor of softwoods and 

 preferred hardwoods. The birches are of great present and pros- 

 pective value, commercially, and their forest value is hardly less 

 than that of beech and maple. Their maintenance in the stand 

 should, therefore, be one of the objects of silviculture wherever the 

 climate and soils are favorable. In the Lake States and at lower 

 altitudes in the mountains the intolerant species — ash, basswood, 

 elm, and red oak — should be given every advantage. As in the 

 natural forest, these will require a commanding position in the crown 

 cover. 



The most desirable composition of the stand will be determined 

 chiefly by the climate and market conditions. In general it will com- 

 prise a shady, tolerant understory and an intolerant overstory of 

 the most valuable species, hard and soft. The understory will con- 

 sist largely of sugar maple, but with as much yellow or black birch 

 as can be secured, and possibly a subordinate growth of red spruce 

 or hemlock. The overstory will be of ash, basswood, white pine, or 

 elm, or of any combination of these that the climate permits and the 

 local demand indicates. Where black cherry, red oak, walnut, or 



