Sma 1 1 mamma 1 s 



The success of natural and artificial regeneration can be affected 

 adversely by seed-eating mammals. Forest managers need to know what 

 levels of small mammal populations can be tolerated in direct seeding 

 and in planning for natural regeneration. Information is also needed 

 on how control measures should be designed in relation to small mammal 

 population characteristics. 



Studies of forest-small mammal relationships have been started in South- 

 east Alaska in cooperation with the U. S. Fish and Wildlife Service. 

 Published and unpublished sources show that small mammals occurring in 

 Southeast Alaska include three species of shrews (Sorex) , two species of 

 white-footed mice ( Peromyscus ) , and six species of voles (Microtias and 

 Clethrionomys ) . 



Small mammal population studies on ten 5-acre plots in the Maybeso 

 Experimental Forest clear cutting showed that animal density was as high 

 as six per acre and was greater in the valley bottom sites than on side- 

 hills. Shrew populations were concentrated on the most recently logged 

 sidehill sites. Meadow voles were limited to areas of succulent 

 vegetation. 



Populations of from one to three white-footed mice per acre were almost 

 entirely eliminated on two 75-acre plots broadcast-sown with sodium 

 f luoroacetate treated wheat. On the valley bottom sites the re- 

 establishment of original population levels was nearly complete 14 weeks 

 after poisoning. In this period the population on sidehill sites re- 

 turned to about one-half of the original level. The usefulness of 

 poisoned baits appears to be limited because the population vacuum 

 created is quickly reoccupied. 



Direct seeding 



The average cutover area will have sites, particularly along streams or 

 valley bottom flats, where brush invasion may preclude or delay natural 

 regeneration. In the absence of a good natural seed crop, such areas 

 may need artificial seeding immediately after logging to establish re- 

 production before brush competition becomes a problem. Such" areas will 

 probably average only about five percent of the total cutover commercial 

 forest land in Southeast Alaska, but they include the most productive 

 sites. 



Studies were started in May 1957 on nine one-acre plots seeded by 

 natural seed fall, and artificially with Endrin- treated seed and 

 untreated seed to determine if satisfactory stands of western hemlock 

 and Sitka spruce reproduction could be established by broadcast seeding. 

 Results in the fall of 1957 showed that Endrin may be an effective 



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