3o8 Forestry Quarterly. 



SILVICULTURE, PROTECTION, AND EXTENSION. 



Dr. Matthes furnishes a very interesting 

 Influencing and important contribution to our knowl- 



Root edge of symbiotic processes which may be 



System utiUzed in silviculture. It has reference to 



of the possibility of influencing the root sys- 



Spruce. tem and therewith the growth energy of 



spruce on poor soils. Such influences 

 should be to increase the number of roots without too much 

 root competition, an increase of "anchor" roots which penetrate 

 more deeply into fertile soil, nourish the tree better and 

 make it windfirm, thereby avoid tearing of roots and the con- 

 sequent root rot. A series of experiments lasting through lo 

 years are at the basis of his conclusions. 



A 1 2-year-old plantation of 4-year-old spruce transplants set out 

 on a heath in plats had hardly grown at all, making hardly 16-inch 

 height, one-half inch diameter at base, and three or four pri- 

 mary roots of 8 to 40-inch length with little branching. A part 

 of the plantation was after 4 years from planting fertilized with 

 ammonia-superphosphate, and the fertilizing continued for six 

 years. The plants grew to over 3 feet in height and 2-inch diam- 

 eter with a much larger root system. This fertilizing was, how- 

 ever, expensive, $2 per acre per year, or for the six years $12.00. 



In another series the influence of green manuring and of mixing 

 in Black Locust and Alder was tested. 



The following observation was suggestive: An 18-year-old 

 Spruce of 5-inch diameter and 12 feet height was surrounded by 

 8 alder stocks ; which altogether having still live sprouts had a 

 number of dead roots. Four roots of the spruce had reached one 

 of these dead roots. These roots were unusually stout, i to 2 

 inches in diameter and 32 inches to 8 feet long, while 8 other 

 primary roots which had not reached the alder stocks were less 

 than I inch and quite long, 4 to 10 feet. The former had bored 

 into the rotten alder roots and formed an immense number of 

 fibrils. There were also three "anchor" roots formed which, with 

 a diameter of nearly 2 inches, sunk to a depth of 8 to 14 inches. 



In the experiment proposed and started, the author planted 

 about 2,000 spruce to the acre; after 10 to 15 years he takes out 

 1,200 as Christmas trees which he can sell at a net return of 



