Sonoran life zone of Washington. Amer. Jour. 

 Sci. 239: 503-522. 



Discusses postglacial plant succession. 



HANSEN, H. P. 1943. A poUen study of a sub- 

 alpine bog in the Blue Mountains of northeast- 

 ern Oregon. Ecology 24: 70-78. 



HANSEN, H. P. 1948. Postglacial forests of 

 the Glacier National Park Region. Ecology 

 29: 146-152. 



Discusses postglacial succession. 



HANZLIK, E. J. 1927. Engelmann spruce and 

 lodgepole pine. Four L Lumber News 9(19): 

 8, 40-41. 



HANZLIK, E. J. 1928. Trees and forests of the 

 western United States. 128 pp. Portland: 

 Dunham. 



HARLOW, WILLIAM M. , and ELWOOD S. 

 HARRAR. 1958. Textbook of dendrology, 

 4th ed., 561 pp. New York: McGraw-Hill 

 Book Co . , Inc . 



HARRAR, ELWOOD S. (See Harlow and Harrar. 

 1958) 



HARRINGTON, H. D. 1954. Manual of the plants 

 of Colorado. 666 pp. Denver: Sage Books. 



Taxonomy of Colorado plants . 



HARRISON, B. F. (See Christensen and 

 Harrison. 1961) 



HARSHBERGER, JOHN W. 1958. Phytogeo- 

 graphic survey of North America. 790 pp. 

 2d (Reprint) ed. Weinheim/Bergstr., Germany: 

 H. R. Engelmann (J. Cramer). 



HARTLEY, CARL. 1921. Damping-off in forest 

 nurseries. U.S. Dept. Agr. Bui. 934, 99 pp. 



Relative susceptibility to damping-off of dif- 

 ferent conifer species. 



HARTLEY, CARL, and ROY G. PIERCE. 1917. 

 The control of damping-off of coniferous seed- 

 lings. U.S. Dept. Agr. Bui. 453, 32 pp. 



Soil-disinfection tests on Engelmann spruce in 

 Colorado and New Mexico. 



HARTLEY, CARL, T. C. MERRILL, and A. S. 

 RHOADS. 1918. Seedling diseases of coni- 

 fers. Jour. Agr. Res. 15: 521-558. 



Discusses damping-off in Engelmann spruce 

 seedlings . 



HARTLEY, CARL. (See Rhoads et al. 1918) 



HARTLEY, CARL, ROY G. PIERCE , and 

 GLEN G. HAHN. 1919. Moulding of snow- 

 smothered nursery stock. Phytopathology 9: 

 521-531. 



BotrytLs cinerea ; Pestalozyia sp. 



HATT, ROBERT T. 1943. The pine squirrel in 

 Colorado. Jour. Mammal. 24:311-345. 



Reports use of Engelmann spruce as food by 

 pine squirrel and distribution of pine squirrel in 

 Engelmann spruce stands. 



HAWKSWORTH, FRANK G. , and DONALD P. 

 GRAHAM. 1963. Dwarfmistletoes on spruce 

 in the western United States. Northwest Sci. 

 37: 31-38. 



HAWKSWORTH, FRANK G. , and THOMAS E. 

 HINDS. 1959. Progress report on the rate 

 of deterioration of beetle -killed Engelmann 

 spruce in Colorado. U.S. Forest Serv., 

 Rocky Mountain Forest and Range Expt. Sta. 

 Res. Note 36, 6 pp. 



HAWKSWORTH, FRANK G. , and THOMAS E. 

 HINDS. 1960. Cytospora canker of Engel- 

 mann spruce in Colorado. Plant Dis. Rptr. 

 44: 72. 



HAYWARD, C. LYNN. 1945. Biotic communi- 

 ties of the southern Wasatch and Uinta Moun- 

 tains. Great Basin Nat. 6: 1-124. 



Community description. 



HAYWARD, C. LYNN. 1952. Alpine biotic 

 communities of the Uinta Mountains, Utah. 

 Ecol. Monog. 22: 93-120. 



Description of spruce -fir zone is included. 



HAYWARD, C. LYNN. (See Tanner and 

 Hayward. 1934) 



HEDGCOCK, GEORGE GRANT. 1912. Notes on 

 some diseases of trees in our national forests. 

 II. Phytopathology 2: 73-80. 



Reports on several diseases of Engelmann 

 spruce . 



HEDGCOCK, GEORGE GRANT. 1912. Notes on 

 some western Uredineae which attack forest 

 trees. Mycologia 4: 141-147. 



14 



