ILLUSTRATIONS 



FIQ. PAGE 



1. The forest regions of the United States viii 



2. The location and relative size of the National Forests xi 



3. Natural reproduction in an open space in a virgin forest 5 



4. Incomplete natural reproduction after lumbering and fire 6 



5. A pure stand of white pine after a reproduction cutting 11 



6. Excellent natural reproduction of white pine attained under a 



shelterwood 11 



7. Natural reproduction in groups 13 



8. Scattered seed trees left to provide seed for the natural regeneration 



of beech and to supplement the artificial regeneration of spruce 14 



9. Plantation of blue gum (Eucalyptus globulus), 28 years old 19 



10. Poor form and growth in a plantation of Scotch pine due to acid 



soil 33 



11. A mixed, uneven-aged stand of hardwoods and conifers 47 



12. A 40-year old plantation of Norway spruce spaced 4 by 4 feet, in 



which about two-thirds of the trees have been removed in the 



thinnings 57 



13. An unthinned white pine plantation 44 years old and spaced 8 by 8 



feet 58 



14. An overwood of oak with an underwood of beech 69 



15. Reforestation by direct seeding in spots after a clear-cutting 84 



16. A large opening caused by windfall which made planting necessary 



in a forest otherwise reproduced by natural regeneration 88 



17. A plantation of Norway spruce 17 years old from Austrian seed. . 93 



18. Greenhouse benches arranged for germination tests 115 



19. An improvised germinating apparatus 116 



20. Cross section of Stainer's germinating apparatus 117 



21. Germinating flask 118 



22. The Geneva seed-tester 118 



23. Standard seed-germinating oven 119 



24. Tools useful in detaching the fruit of forest trees. 142 



25. Gathering cones from a squirrel cache at the base of a tree 144 



26. Drying yellow pine cones by solar heat near Golden, Colorado 149 



27. Storage building for pine and spruce cones 151 



28. Removing the seed from dried Douglas fir cones 158 



29. Seed-extracting plant at Wyeth, Oregon 162 



30. Cross section of the Annaburg seed-extracting plant 164 



31. A broad fire line adjacent to a public highway protecting a white 



pine plantation 185 



xix 



