xv i CONTENTS 



CHAPTER PAGE 



3. Characteristics of tree growth 55 



4. Varieties of trees 56 



5. How trees grow and reproduce 57 



V. FOREST INFLUENCES 61 



1. The forest as a community of trees 61 



2. Silvics or forest ecology 61 



3. Influence of forest on its environment 62 



1. Climate . . 62 



2. Soil 



4. Forest types and their characteristics 63 



5. Pure and mixed forests ..... 65 



6. Factors determining the selection of species 66 



VI. FOREST PROTECTION 67 



1. General . 67 



2. Forest fires importance and extent 68 



3. Causes of forest fires . 73 



4. Methods of detection ...... 74 



5. Methods of prevention 75 



6. Methods of control and suppression 80 



7. Southern forest fire problem 82 



8. Forest insects . . . . . . . . 83 



9. Forest fungi 85 



10. Domestic animals ., . . . . . . ... .... . 88 



11. Wild animals , . . , . . 88 



12. Sand dunes and miscellaneous .......... 89 



VII. FOREST MENSURATION 91 



1. General 91 



2. Units of measure 91 



3. Instruments commonly used . . . ...... . . 92 



4. Log rules 93 



5. Scaling ''- 93 



6. Volume tables . . . . . : . . . .'. . 94 



7. Cruising 94 



8. Yield tables 95 



9. Stumpage and stumpage appraisal 96 



VIII. SILVICULTURE METHODS OF NATURAL REPRODUCTION 99 



1. Definitions and general considerations 99 



2. Advantages of natural versus artificial reproduction . . . 100 



3. Silvicultural systems 101 



4. American versus European silvicultural systems .... 106 



5. Silvicultural systems of cutting some representative types 



in the National Forests 107 



IX. SILVICULTURE METHODS OF ARTIFICIAL REPRODUCTION (REFORES- 

 TATION OR TREE PLANTING 113 



1. History and development 113 



2. Conditions requiring tree planting 116 



