iUKEBT SERVICE. 7 



resources and forest use thru making ready special publications in 

 popular form, thru cooperation with teachers and officers of public 

 instruction, and thru further systematization and extension of lec- 

 tures and addresses. 



SILVICS. 



The work of the year in Silvics followed two main lines — collect- 

 ing, critically examining, and systematically organizing • the data 

 already gathered by past studies of the Forest Service or accessible 

 from other sources, and establishing permanent sample plots for 

 gathering new data. 



A knowledge of the requirements of the various species which 

 form the forests of the United States, and of their behavior under 

 varying conditions, is the foundation of intelligent forest manage- 

 ment. Yet the vastness of our forested area, the wide range of cli- 

 matic and other conditions, and the great number of species found 

 make the gathering of this knowledge a huge task, which systematic 

 study by foresters has only begun to attack. The problems of man- 

 agement which the care of the national forests imposes upon the 

 Service makes the need of such laiowledge urgent. 



During the year data were compiled for 67 species. Their range, 

 rate of growth, light, moisture, and soil requirements, reproduction, 

 and behavior in pure stands and in competition with other species 

 were among the subjects treated. At the same time notes were gath- 

 ered as to the silvical conditions of 41 of the forest reserves. 



Work on permanent sample plots was done chiefly on loblolly pine 

 in South Carolina and Maryland, white pine in Massachusetts and 

 NeAV Hampshire, and red spruce in New Hampshire. A less amount 

 of work was done on thinnings in chestnut coppice in mixture with 

 white and red oak and other species in Connecticut; on yellow 

 birch in mixture with paper birch, sugar maple, black cherry, and 

 other species in New Hampshire, and on scrub pine in Maryland. 



The study of loblolly pine in Maryland was to learn, first, what 

 different densities of seedling stands will produce, and what consti- 

 tutes a full stand; second, the effects of thinnings in even-aged 

 stands at various stages. Separate series of plots were established in 

 pure stands on several different soils. A few plots were taken in 

 stands where loblolly was growing in mixture with hardwoods. 

 The plots are in Worcester County, where the growth is rapid, where 

 the greater part of the land is probably better suited for growing 

 pine than for agriculture, and where much land formerly under culti- 

 vation is now going back into even-aged stands of loblolly. 



The South Carolina plots deal also with the effects of fire. 



The white pine plots in Massachusetts and New Hampshire will 

 furnish data concerning thinnings in young stands, the effect of 

 thinning upon partially supprest trees and their ability to recover 

 after the removal of larger trees, and thinning in an overcrowded 

 stand of pine. 



WORK or THE COMING YEAR. 



New sample plots will be laid out in the North and Middle Atlantic 

 States. Data will be gathered concerning red spruce, balsam, white 

 pine, and mixt hardwoods. Among the subjects of investigation will 

 be the effect of different methods of planting, thinning, and lumber- 

 ing upon the present and future forest. 



