22 THE NATIONAL FOREST MANUAL. 



oughly. It should be done after rains or whenever the soil shows 

 signs of baking or drying. 



Where winters are severe, it is advisable to mulch the seed beds to 



protect the seedlings from injury by cold or drying 

 ^Protection in win- w i n d Sj as well as to keep the ground from heaving in 



the spring. Where snow lies ah 1 winter, mulching is 

 unnecessary. Any substance, such as leaves, straw, or moss, which 

 is free from weed seed, placed in a layer from 3 to 4 inches deep, is 

 suitable. The mulch can be held in place by laying sticks or strips 

 of boards across the beds between the rows. It should be removed 

 at the beginning of the growing season. 



In the spring, when the soil is in good workable conolition, but before 



a new growth begins, evergreen seedlings when 1 or 2 

 ttns ' years old should, in some cases, be transplanted to 

 open nursery rows. Transplant beds should be near the seed beds 

 and on good soil which has been thoroug;hly prepared. Transplant 

 beds should be slightly elevated, 6 feet wide, and of any convenient 

 length, with rows 8 inches apart running across the beds. The seed- 

 lings should be set free from 2 to 4 inches apart in the rows, the exact 

 distance depending upon the size of the plants. In transplanting the 

 roots of the seedlings should not be allowed to become dry, since even 

 a short exposure to sun or air will be fatal. They can best be carried 

 roots downward in a pail containing 4 or 5 inches of water. 



PROTECTION -AGAINST RODENTS. 



Great damage is done by mice, wood rats, squirrels, chipmunks, 

 gophers, and rabbits in nurseries, seeding areas, and 

 young plantations. Before establishing a nursery or 

 plantation or seeding denuded areas, therefore, the presence of de- 

 structive rodents should be carefully investigated. 



The cost of the protective method adopted must be worked out in 



detail, as it may be found upon investigation that 



really effective protection will cost more than the 



results justify, and that it will be preferable to abandon the project 



and select a new site in a less infested locality. 



For the protection of nurseries against rabbits a small-mesh chicken- 

 wire fence may be used. This should reach at least 

 3 feet above ground and one-half foot below. The 

 portion below the surface should be bent in toward the ground to be 

 protected at an angle of 45, so that the burrowing animal will come 

 up against it diagonally when trying to reach the surface. 



Many types of traps for catching rodents are in use. Forest officers 



engaged upon such work should fully investigate their 



effectiveness. Information concerning special kinds 



of traps may be secured from the Biological Survey upon application 



through the Forester. 



The best results in the extermination of rodents have been obtained 

 from the use of poison. The following formulas and 

 directions are recommended by the Biological Survey 

 after a series of experiments in the field: 



