Circular No. 791 



October 1948 • Washington, D. C 



UNITED STATES DEPARTMENT OF AGRICULTURE 



Silvicultural Management of Black Spruce 

 in Minnesota 1 



By Russell K. LeBarron, 2 Silviculturist, Lake States Forest Experiment Station, 3 



Forest Service 



CONTENTS 



Introduction 



Range and occurrence 



Present area and volume 



Description of stands and 



growing conditions 



Swamps 



Uplands 



Trends in forest succession 



Succession in natural stands 



Swamps 



Uplands 



The effect of forest fires 



The effect of logging prac- 

 tices 



Conditions affecting regenera- 

 tion 



Seed supply and dissemina- 

 tion 



Germination and establish- 

 ment of seedlings 



Reproduction by layering 



Growth and yield 



Growth in relation to site 

 quality 



Yields of understocked and 

 uneven-aged stands 



Page 

 2 

 6 



9 

 9 

 11 

 12 

 13 

 13 

 13 

 14 



18 



20 

 20 



21 



26 



27 



28 

 31 



Growth and yield — continued 



Longevity 



The effect of insect and dis- 

 ease enemies on growth 



Response of black spruce to 



swamp drainage 



Silvicultural operations — cutting 



and regeneration 



Thrifty swamp stands 



Application of partial cut- 

 tings 



Postcutting mortality 



Growth in cut-over stands.— 



Strip cutting 



Christmas tree operations, _ 



Decadent swamp stands 



Clear cutting 



Control of dwarf mistletoe__ 



Upland stands 



Pure type on well-drained 



uplands 



Swamp border type 



Mixed types 



Summary 



Literature cited 



Appendix 



Page 



33 



34 



36 



36 

 37 



37 



41 

 44 

 45 

 47 

 48 

 48 

 50 

 50 



50 

 52 

 52 



52 

 54 

 56 



1 Submitted for publication April 19, 1948. 



2 The author wishes to acknowledge his indebtedness to Sam Dolgaard, senior 

 timber appraiser, Earl Adams and George B. Ainidon, formerly timber appraisers, 

 Minnesota Department of Conservation, and H. L. Sundling, Superior National 

 Forest, all of whom cooperated generously in the conduct of field work and 

 supplied many suggestions ; W. R. Isaacson and G. W. Kruse, formerly junior 

 foresters, Civilian Conservation Corps, who assisted in field measurements ; 

 and R. N. Cunningham, forest economist, Lake States Forest Experiment Station, 

 who furnished data on timber areas and volumes. Particular credit is due to 

 F. H. Eyre, in charge of Forest Management Research, Lake States Experiment 

 Station, for guidance and advice throughout the entire project upon which this 

 report is based. 



3 Maintained by the United States Department of Agriculture at University 

 Farm, St. Paul, Minn., in cooperation with the University of Minnesota. 



792021° — 48 1 1 



