1 .9622 

 I2R312 



UNITED STATES DEPARTMENT OF AGRICULTURE 

 FOREST SERVICE 



INTERMOUNTAIN FOREST & RANGE EXPERIMENT STATION 



OGDEN UTAH 



No. 99 September 1962 



AN APPRAISAL OF LOGGING DAMAGE TO ADVANCE REPRODUCTION 



OF PONDEROSA PINE j 2^ 



Marvin W. Foiles 

 Division of Forest Management Research 



ABSTRACT 



Heavy cutting in ponderosa pine stands in central 

 Idaho caused significantly greater damage to the 

 understory than light cutting. Damage was nearly 

 the same for stands marked by group selection and 

 stem selection, logged by large and small tractors, 

 and with original overstory volumes of 10,000 to 

 more than 20,000 board feet per acre. 







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INTRODUCTION 



Regeneration of logged ponderosa pine stands in the Intermountain Region is 

 often a difficult and expensive operation. Therefore, occurrence of advance re- 

 production as an understory is a very valuable asset. Where it occurs in sufficient 

 amount and is given reasonable protection, it will insure establishment of the 

 future stand. The great value of advance reproduction emphasizes the need for care 

 in logging the overstory to avoid excessive damage to the understory. The initial 

 logging in an experiment of single tree and group selection cuttings in ponderosa 

 pine in 1953 and 1954 gave opportunity to measure logging damage to advance repro- 

 duction and to pole stands as affected by different cutting methods and logging 

 tractors. This note reports the reduction in understory stocking caused by logging. 



THE STUDY 



The studyl/ included 847 acres of the Boise Basin Experimental Forest, Idaho 

 City, Idaho. The area was divided into 16 compartments, each of which was a minor 

 drainage. The 16 compartments included two replicates of eight compartments each, 

 representing the eight combinations of major treatments. The major treatments in- 

 cluded: (1) two reproduction methods (stem selection and group selection) , (2) two 

 levels of reserve stand volume, and (3) two sizes of logging tractors (D-4 and D-8 

 caterpillar tractors without bulldozer blades). 



JL/ Curtis, James D. A study of ponderosa pine production in central Idaho. 

 U.S. Forest Serv. Intermountain Forest and Range Expt. Sta. Misc. Pub. 4, 9 pp., 

 illus. 1955. 



