82 FORESTRY [Bot. Absts. 



559. Mitchell, J. A. Bear clover. Jour. Forestry 17: 39-43. 1919. — A study of bear- 

 clover (Chamoebatia foliolosa) on the Eldorado and Stanislaus forests [western U. S. A.] in 

 1912 indicates that forest reproduction is adversely affected by a bear-clover ground cover and 

 that the relative percentage of incense-cedar reproduction increases, while that of pine repro- 

 duction diminishes, as the density of bear-clover increases. In extremely heavy stands all 

 reproduction is excluded. — E. N. Munns. 



560. Munns, Edw. N. Some biological and economic aspects of chaparral. Jour. For- 

 estry 17: 9-14. 1919. — The relationship between chaparral and tree-growth in the transition 

 belt in western U. S. A. is pointed out, with consideration of the bearing of the brush on the 

 problem of forestation. By coppicing, chaparral forms a soil cover quickly after fire and it 

 is valuable as a soil binder, preventing erosion and landslides. The economic value of chapar- 

 ral is briefly discussed. — E. N. Munns. 



561. Munns, Edw. N. Women in southern lumbering operations. Jour. Forestry 17: 

 144-149. 1919. — Owing to the shortage of labor in the South [U. S. A.] during the latter part 

 of 1918, women undertook much work formerly done by men. Few positions in the woods, 

 mill, or office were not occupied by women, who generally proved satisfactory. — E. N. Munns. 



562. Myhrwold, Prof. Skogkultur i Frankrike. [French silviculture.] Tidskr. Skog- 

 bruk 27: 8-15. PL 1-7. 1919. 



563. Nansen, Fritjof [and others]. Frankrike-Norge-Skogen. [France-Norway for- 

 ests.] Tidskr. Skogbruk 27: 1-8. 1919. — Original correspondence between the two govern- 

 ments relating to proposed plantations of Norway spruce in France by Norwegian foresters. — 

 /. A . Larsen. 



564. Pearson, G. A. [Rev. of: Hesselman, Henrik. Soil nitrification in relation to 

 forest reproduction. Skogsvordsforeningens Tidskr. (Haft 1) 104 P- 1918.] Jour. Forestry 

 17: 69-73. 1919. — Investigations of the absence of forest reproduction on the heath lands of 

 northern Sweden showed that the chemical condition of the floor was of more importance than 

 was soil moisture deficiency. Most of these forest soils are characterized by the fact that 

 transformation of organic matter toward nitrates stops with the formation of ammonia. This 

 is remedied by clear cutting or heavy thinning or by cultivation or burning. The result is 

 due to the activity of bacteria which require salts for development. The condition of the soil 

 may be determined by the vegetation cover, certain plants indicating nitrogen deficiency. — In 

 America, the application of these findings is limited to the humid regions, and it is significant 

 that heavy cutting and burning are practiced in the douglas fir region. In open yellow pine 

 stands the soil has a deficiency of litter and humus, except under old trees, and reproduc- 

 tion occurring under such circumstances is due more to better moisture conditions than to 

 improved chemical conditions of the soil. Lack of reproduction in these yellow pine forests 

 is due to poor soil moisture conditions at a critical period in the life-history of the tree. — 

 E. N. Munns. 



565. Recknagel, A. B. Timber census in the northeastern states [U. S. A.]. Jour. For- 

 estry 17: 178-179. 1919. — A timber census was made of the northeastern states during 1918. 

 The stand of spruce in New York is given as 3,500,000,000 feet. Other data are not yet com- 

 piled — E. N. Munns. 



566. Record, S. J. Mahogany and some of its substitutes. Jour. Forestry 17: 1-8. 

 1919. — A key is given embracing the woods known in the trade as 'mahogany," or used as 

 substitutes for the wood to which this name belongs. Representatives of 13 families and 27 

 genera are described, 11 genera belonging to the mahogany family, Meliaceae. The key is 

 based on gross and lens characters. [See Bot. Absts. 2, Entry 748.] — E. N. Munns. 



