(1810) Sowder, James E. 



1953. Lumber grade recovery from young ponderosa pine. U.S. Forest Serv. Pacific 



Northwest Forest and Range Exp. Sta. Res. Note 88, 2 pp. 



(1811) 



1960. Seeding grass on areas disturbed by logging or fire on eastside Oregon and Wash- 

 ington forests . Soc. Amer. Forest. Proc. 1959: 166-168. 



(1812) Spada, Benjamin. 



1960. Estimating past diameters of several species in the ponderosa pine subregion of 

 Oregon and Washington. U.S. Forest Serv. Pacific Northwest Forest and 

 Range Exp. Sta. Res. Note 181, 4 pp. 



(1813) Spain, H. M. 



1925. Western yellow pine volume table. Timberman 26(8): 178. 



(1814) Sparhawk, W. N. 



1918. Effect of grazing upon western yellow pine reproduction in central Idaho. U.S. 

 Dep. Agr. Bull. 738, 31 pp. Review in J. Forest. 17: 705-707, 1919. 



(1815) Spencer, Donald A. 



1954. Rodents and direct seeding. J. Forest. 52: 824-826. 



(1816) 



1964. Porcupine population fluctuations in past centuries revealed by dendrochronology. 

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(1817) and Nelson B. Kverno. 



1952. Research in rodent control to promote reforestation by direct seeding. U.S. 



Fish & Wildlife Serv. Wildlife Res. Lab. (Denver, Colo.) 1952 Progr. Rep. 

 3, 66 pp.; 1953 Progr. Rep. 4, Sect. 1, 39 pp.; Sect. 2, 28 pp. 



(1818) Spencer, John S. , Jr. 



1964. Forest products output in Utah and Nevada, 1962. U.S. Forest Serv. Res. Pap. 

 INT-12, 10 pp. 



(1819) 



1964. Utah's forest area and timber volume. U.S. Forest Serv. Res. Note INT-27, 

 4 pp. 



(1820) and Thomas O. Farrenkopf. 



1964. Timber products output in Colorado, Wyoming, and western South Dakota, 1962. 

 U.S. Forest Serv. Res. Pap. INT- 14, 18 pp. 



(1821) Sperry, O. E. 



1934. The rate of growth of the ponderosa pine in Estes Park, Colorado. Torrey Bot. 

 Club Bull. 61: 19-34. 



(1822) 



1936. A study of the growth, transpiration, and distribution of the conifers of the 

 Rocky Mountain National Park. Torrey Bot. Club Bull. 63: 75-103. 



(1823) Spilsbury, R. H. , J. W. C. Arlidge, N. Keser, and others. 



1963. A cooperative study of the classification of forest land in British Columbia. 



Pp. 503-527. IN: Forest -Soil Relationships in North America (Chester T. 

 Youngberg, Ed.). Oreg. State Univ. Press. (Other authors: L. Farstad 

 and D. S. Lacate) 



(1824) Sproat, W. J. 



1930. Natural reproduction of western yellow pine . J. Forest. 28: 334-337. 



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