INITIAL VEGETAL DEVELOPMENT FOLLOWING PRESCRIBED BURNING 



OF DOUGLAS -FIR IN SOUTH-CENTRAL IDAHO 



L. Jack Lyon 

 INTRODUCTION 



Prescribed fires, particularly in logging slash, are not unusual in the forests of the north- 

 ern Rocky Mountains. Burning is an effective means of reducing wildfire hazards and preparing 

 timber sites for regeneration. Fires in standing timber, on the other hand, have become rela- 

 tively uncommon in this age of smokejumpers , retardant bombers, and fast transportation. 

 And, even though uncontrolled forest fires do occur occasionally, it is impractical to plan 

 studies of specific forested areas that might be burned. The probability of a burned area large 

 enough for study is low, and at best the occurrence of wildfire on areas marked for study would 

 be extremely fortuitous . Thus when personnel of the Sawtooth National Forest intentionally 

 burned 120 acres of standing Douglas-fir on the first day of August, 1963, the situation was 

 virtually unique. 



The basic objectives of this prescribed fire were sanitation and site preparation for silvi- 

 cultural purposes. A stand of Douglas-fir in Neal Canyon on the Ketchum Ranger District had 

 been logged over twice since 1950, and the remaining trees were mostly mistletoe-deformed 

 saplings and poles. After the diseased trees were burned, parts of the area were planted and 

 parts were direct-seeded to establish a new and healthy timber stand. 



From a wildlife management viewpoint, the secondary effects of the fire were as signifi- 

 cant as accomplishment of the primary objectives. Here, for example, was an opportunity to 

 measure the heat output of a fire similar to an uncontrolled forest fire; to investigate the 

 influence of a prefire plant community on postfire vegetal development; and to evaluate the post- 

 fire plant community as wildlife habitat. This paper is a report of the first 3 years of study on 

 the Neal Canyon prescribed burn. Particular emphasis has been given to the relationship be- 

 tween big- game forage values in the forest community and the influence of fire on those values. 



STUDY AREA 



Neal Canyon is a small drainage off Eagle Creek and the Big Wood River about 6 miles 

 north of Ketchum, Idaho. The 120-acre burned area is 1.5 miles east of U.S. Highway 93 in 

 the northeast quarter of Section 13, Township 5 North, Range 17 East, Boise Meridian. Its 

 general aspect is north -northeast, and the elevation is 6,500 to 7,000 feet. Since some parts 

 of the area had been heavily disturbed during logging, the specific site selected for examination 

 was a 20-acre patch of less -disturbed terrain on the lower middle slope (see fig. 1). The true 

 aspect of the study site is N 10-20° E; the slope is 64 percent. 



In this part of Idaho, summers are cool and winters rigorous. Annual precipitation at the 

 Hailey and Sun Valley weather stations is 14 to 17 inches, most of which falls in the winter. 

 Total snowfall at the respective stations averages 85 to 120 inches. The January mean min- 

 imums are within a few degrees of zero and the record minimums for the two stations are —36° 



