INTRODUCTION 



Recently there has been renewed interest in 

 partial cutting in western conifer stands. Histori- 

 cally, much of the virgin forest was initially logged 

 selectively— removing only trees of high value- 

 but for most of the past three decades clearcutting 

 has predominated. With more complex manage- 

 ment objectives and environmental concerns, 

 managers are now frequently turning to some type 

 of partial cutting. They are asking questions about 

 the impacts of partial cutting on costs, silvicultural 

 success, esthetics, wildlife, and other manage- 

 ment considerations. 



This paper reports initial logging damage to 

 residual trees in six harvest units in Douglas- 

 fir/western larch (Pseudotsuga menziesii/Larix 

 occidentalis) forests at the Coram Experimental 

 Forest (Flathead National Forest) near Hungry 

 Horse, Mont. The appraisal includes damage to 

 marked "leave" trees in two shelterwood units, 

 and damage to understory conifers in clearcut and 

 group selection cutting units where the under- 

 story was to be protected. 



The logging was part of a larger program of 

 studies dealing with impacts of residue utilization 

 and disposal. (Detailed plans on other studies are 

 available at the Hungry Horse Ranger District or 

 Forestry Sciences Laboratory, Missoula.) 



The damage reported here was observed within 

 the first year of logging. Secondary effects of 

 windthrow, insects, and disease are beyond the 

 scope of this report, but are being followed in long- 

 term studies. 



SHELTERWOOD LEAVE TREE 

 DAMAGE 



Description of the Area and 

 Cutting Units 



Two shelterwood cutting units (blocks 11 and 



21) were marked so as to leave about half of the 

 volume of trees 7 inches d.b.h. (18 cm) and larger, 

 and to provide good vigor, spacing, and species 

 diversity. Within each cutting unit, four utilization 

 and postharvest treatments were used: 



Treatment Specifications 



1 All material at least 8 feet (2.4 m) long with 

 at least a 3-inch (7.6-cm) diameter (small 

 end) was removed (this included trees 

 down to a 5-inch [1 2.7-cm] d.b.h.). Residue 

 was burned after harvest. 



2 Trees down to a 7-inch (1 8-cm) d.b.h. were 

 cut, logs down to a 6-inch (15.2-cm) top 

 diameter were removed; residue was 

 burned after harvest. 



3 All trees down to a 1-inch (2.5-cm) d.b.h. 

 were cut and removed; the area was left 

 "as is" after harvest. 



4 Trees down to a 7-inch (1 8-cm) d.b.h. were 

 cut, logs 8 feet (2.4 m) long down to a 3- 

 inch (7.6-cm) diameter were utilized; re- 

 maining trees were protected as far as 

 possible and left as advanced regenera- 

 tion. 



Although the two units had many similarities and 

 the treatments were identical, differences in ter- 

 rain possibly influenced logging damage. The 

 units are reported here as separate "case studies" 

 rather than as replications. 



A summary of the preharvest stand conditions is 

 shown in table 1. This is a fairly typical fir-larch 

 stand, and like most natural stands, fire, disease, 

 blowdown, etc., have left a mosaic of old and young 

 trees. This is reflected in the variation in volumes 

 among treatments. The cut tree volume as cruised 

 varied from 4.5 to 9.5 M bd. ft./acre (approximately 

 63 to 133 m 3 /ha). We anticipated that about 15 

 percent of the leave tree volume would be lost in 

 the logging process; therefore somewhat more 

 volume was removed than was shown in the 

 cruise. 



1 



