Changes Over Time After 

 Harvest in Clearcuts 



The above studies apparently show that viewers' ratings 

 of post-harvest activities are related to the length of time 

 the area has for recovering as well as to different treat- 

 ments. In both the Teton and Coram study areas cited 

 above an improvement of viewers' rating was often noted 

 in later years. 



We hypothesized that changes in viewer ratings after 

 harvest are related to growth in vegetation, since this is 

 the principal visual change on the site. To evaluate the 

 effect of vegetation development, we selected and 

 photographed a series of sites at different stages of 

 succession following harvest. Two forest types were in- 

 cluded; lodgepole pine and Douglas-fir/larch. The stages 

 we included were: first year after treatment; several years 

 later when herbs, grass, shrubs, etc., had developed so as 

 to give a "green" appearance; later, when young trees 

 began to be distinguishable (usually 5 to 15 years); later 

 when the young stand is large enough to be considered an 

 established vigorous forest (about 25 to 50 years), and 

 finally when the stand has reached maturity. To assure 

 reasonable comparison we selected only sites that had 

 been clearcut and burned (except for the mature stands 



where origin could not be identified, but probably is 

 not important at that age). 



The ratings by panel 5, shown in figure 5, typified the 

 trend in ratings we had expected. Both the Douglas-fir 

 and larch (DF/L) and the lodgepole pine (LPP) harvest 

 areas were rated low initially. About 10 years after 

 harvest the DF/L had reached a point on the "like" portion 

 of the scale, probably because these stands are on moist 

 sites that "green up" quickly (undergrowth is lush) and 

 trees begin to grow rapidly. LPP took longer to reach this 

 point reflecting the generally sparser vegetation and 

 slower tree growth. When stands had reached heights of 

 about 25 to 75 feet and crowns were green and vigorous, 

 ratings were the highest. 



In mature stands aged 150 years or more, ratings were 

 lower. We can speculate that this is due to more dead 

 material and debris, and also that the mature stands with 

 a high dense canopy are darker and more enclosed than in 

 younger stands. The exact age or condition at which 

 ratings begin to decline could not be determined from this 

 preliminary study. Such information might be useful in 

 managing such areas as campgrounds, recreation areas, 

 and nature trail areas. Detailed ratings of this study are 

 in table 5. 



Table 5.-Mean ratings of lodgepole pine and Douglas-fir/larch forests over time following clearcut harvest and slash burning 

 Type of forest and 



years after harvest Viewer paneP 



Douglas-fir/larch 

 1-2 

 5 



10 

 18 



23 



30-50 



Mature (150) 



Lodgepole pine 

 1-2 

 4-5 

 15-20 

 25.50 



Mature (150) 

 (Critical diff.)' 



2 76 



3 66 



6 12 

 6.04 



6,27 



1.19 

 2.22 



4 30 

 (.60) 



4.80 



6.21 

 6.63 



6.29 



1.46 

 2.65 



4.70- 

 (.60) 



-Mean rating- 



3.23 



6.51 

 7 23 



7.39 



1.07 

 1.99 



4.58 

 (-60) 



3.96 



5.56 

 5 89 



6.60 



1.37 

 2.80 



4.98 

 (.60) 



2.22 

 5 15 



6 81 

 5 9^ 



2.37 

 5.51 

 7.33 

 5.50 

 (.84) 



'Panel numbers refer to following. 

 1. University of Ivlontana psychology students. 1973, 

 2 University of Mictiigan psychology students. 1973, 



3. IVIontana public school teachers, 1973, 



4. USDA Forest Service researchers, 1973, 



5. University of IVIontana psychology students, 1979 



'Differences between means that exceed this are significant at the 95 level 

 'This panel did not evaluate this scene 



10 



