INTRODUCTION 



Much has been written concerning the seedbed requirements for efficient natural 

 regeneration of Engelmann spruce (Picea engelmannii Parry) , western larch (Larix 

 occidentalis Nutt.) and their associated species (Lowdermilk 1925, Barr 1930, Smith 

 1955, Day 1964, Roe 1952, Roe and DeJarnette 1965, and Alexander 1966). Seedling 

 establishment is favored by the exposure of mineral soil through scarification and, to 

 a lesser extent, by burning. It is generally agreed that some sort of seedbed prep- 

 aration is necessary for prompt and adequate reproduction. But what is the best way to 

 create the optimum environmental conditions? Is the scarification that results from 

 logging sufficient--or should additional mechanical scarification be used? Is prescribed 

 broadcast burning more efficient? Can the composition of the future stand be controlled 

 by modifications of the site-preparation m.easures? These were the objectives of a 

 cooperative study started in a northern Idaho larch-spruce stand in 1954.-^ 



STUDY AREA 



The study area is located on Roundtop Mountain in the St. Joe National Forest in 

 northern Idaho. The entire study area is on a northerly aspect at an elevation of 5,200 

 to 5,800 feet and is representative of the Picea - Abies/Menziesia habitat type (Daubenmire 

 1952). 2 



The existing mature stand was over 200 years old and averaged approximately 13 MBF 

 per acre. Composition of the main merchantable stand, based on the number of trees per 

 acre, was as follows: 



Occurrence 



Species in total stand 



Western larch ( Larix o ccidentalis Nutt.) 56% 



Engelmann spruce ( Picea engelmannii Parry) 22% 



Mountain hemlock ( Tsuga mertensiana (Bong.) Carr.) 15% 



Subalpine fir ( Abies lasiocarpa (Hook.) Nutt.) 7% 



Minor amounts of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco), western white pine 

 (Pinus monticola Dougl.) and grand fir (Abies grandis (Dougl.) Lindl.) were also present. 

 Stands were rather open with an almost continuous undergrowth of false huckleberry 

 (Menziesia ferrugina Sm.). 



Approximately one-half of the volume on the area was harvested in 1951-53 by the 

 strip-clearcutting method. The cut strips averaged 640 feet in width and 2,200 feet 

 in length, with the long axis extending up and down the slope and in a north-south 

 direction (fig. 1). The intervening uncut strips were approximately the sariie size. 



^Cooperators included: Potlatch Forests, Inc.; the St. Joe National Forest; the 

 University of Idaho College of Forestry; and the Northern Pacific Railway Company. 



The study was designed by C. A. Wellner. Initial measurements were made by R. F. 



Watt . 



^The area would be reclassified as Tsuga mertensiana/Menziesia according to re- 

 visions in classification planned by Dr. Daubenmire (personal communication). 



