646 IXPBSIMENT STATION BBCOBD. 



FORESTRY. 



Light in relation to tree growth, R. Zon and H. S. Graves {U. S. Dept. 

 Agr., Forest Scrv. Bui. 92, pp. 59, figs. 10). — The aim of this bulletin is to bring 

 together the principal facts relative to the part which light plays in the life 

 of the forest and the different methods of measuring it. It is hoped that it 

 may stimulate an interest to further research to determine more accurately the 

 light requirements of our forest trees, esiiecially by actual measurements of 

 light in the forest. 



The subject is discussed under the following general headings : Kinds of light, 

 light intensities and tree growth, tolerance and intolerance of trees, factors 

 influencing tolerance, measure of tolerance, methods of determining tolerance, 

 and relative value of different methods. 



A bibliography of the subject is appended. 



[Forest plantations], C. B. Waldron (North Dakota Sta. Rpt. 1909, pp. 9^, 

 95). — Among the deciduous trees in the different tree plantations of the station, 

 the green and white ash, soft maple, hackberry, black walnut, and white birch 

 made the most satisfactory growth. The catalpa has been discarded as wholly 

 unsuited to the cliniate. The Norway maple seems to be too tender for general 

 planting. The insect enemies of the cottonwood and Norway and Carolina 

 poplars are increasing so as to discoui*age the general planting of these trees. 

 Considerable difficulty is being experienced in establishing young coniferous 

 trees. 



[Report on forest plantings], C. B. Waldron {North Dakota Sta. Rpt. 

 1910, pp. .'i9, 51). — Brief notes are given relative to the behavior of a number 

 of different species of trees as influence<l by freezing and drought. 



Uses of commercial woods of the United States. — I, Cedars, cypresses, 

 and sequoias, W. L. Hall and H. Maxwell {U. S. Dept. Agr., Forest 8erv. 

 Bui. 95, pp. 62). — This is the first of a series of bulletins in which the aim will 

 be to bring together in convenient form the available information on the uses 

 of the different commercial woods. It is believed that the series will be of 

 especial interest to lumbermen, those engaged in the wood-using industries, and 

 foresters, as well as to instructors and students in forest schools. 



The above species are considered separately, authentic information relative to 

 the physical properties of each species being first presented, after which notes 

 are given on the uses made of each wood from the earliest time, together with 

 a discussion of their various uses at the present time. In addition to original 

 data collected by the Forest Service, the subject matter has been gathered from 

 many and widely scattered sources. 



California tanbark oak (U. 8. Dept. Agr., Forest Serv. Bui. 75, pp. 34, pis. 

 10). — The purpose of this bulletin is to show how the wood of the tanbark 

 oak, which is now left in the forest to rot unused or to add fuel to forest fires, 

 may be utilized and that a careful handling of the woodlands, coupled with 

 conservative lumbering, ought to make the tanbark oak crop continuous and 

 render this resource inexhaustible. 



The bulletin consists of 3 portions. Part 1, Tanbark Oak and the Tanning 

 Industry, by W. L. Jepsou (pp. 5-23), discusses the development of the tanning 

 industry in California, the silvical characteristics of the tanbark oak, the pro- 

 duction of tanbark, the quality of the bark, prolonging the supply, tannin- 

 extract process, and possibilities of utilizing the wood. Part 2, Utilization of 

 the Wood of Tanbark Oak, by H. S. Betts (pp. 24-32), comprises results of 

 tests relative to the strength, seasoning, and shrinkage qualities of tanbark 

 oak, deals briefly with the various hardwoods used on the Coast, and suggests 

 uses for tanbark oak. The appendix, Distribution of Tannin in Tanbark Oak, 



