iation estimates were based on the percentage of liye conifers, 30% or more 
defoliated. The defoliation percentage classes were the same as the mortality 
classes. Areas of all type& were determined through the use of a dot-grid. 
However, the average volume loss per acre was determined by an independent 
ground sample of random cluster plots, and was estimated to be 2.76 m^/ha. 
(40 cubic feet per acre) for the entire Park. More important for recreation 
management was the fact that the infestation had caused widespread tree mortal 
ity on 3,100 hectares of the 20,700 hectares in the park, but most of the 
heavy mortality was concentrated within 2,392 hectares of the spruce-fir complex. 
It is erahpasized that the damage survey was done from color-infrared photos 
taken in September, ~ long after the dead-needle detritus has been rain- 
washed away from the trees. Several insect survey personnel maintain that 
the red-brown needle detritus must be on the tree when any budworm damage 
survey is done. 
Over the last couple of years, the gypsry moth QPorthetria dispar) 
has caused defoliation of an estimated 1.4 million acres (566,000 hectares) of 
forests in the north eastern United States. After a film/filter test, it was 
concluded that Plus-X film and a 25A filter were a satisfactory combination for 
mapping total defoliation of hardwoods, however, color-infrared was considered 
superior for detecting and mapping light and medium forest canopy defoliation 
(Rohde and Moore, 1973). On a test site in the State of Rhode Island, three 
levels of hardwood defoliation (light 25-50% defoliated; medium 50-80% defoliated 
and heavy 80-100% defoliated) were mapped. 
A chemical herbicide (Tordon 101) was used to control vegetation 
growth in the International boundary zone between Waterton Lakes National Park, 
Canada, and Glacier National Park (U.S.A.) in 1968. Some of the herbicide 
killed trees in the Parks outside the boundary zone. In order to establish a 
case against future spraying, a survey was done to estimate the damage (tree 
mortality). 1:6,000 scale color-infrared photos were interpreted by counting 
dead tree crowns. Since the principal tree species affected were lodgepole 
pine (Pinus oontorta Dougl.), white spruce (Pioea glauoa (Moench) Voss), and 
alpine fir (Abies Zasiooarpa (Hook) Nutt.) the small size of the defoliated 
dead tree crowns dictated the use of the larger scale. Strips of dead trees 
were noted to adjoin 45% of the forested boundary on the Canadian side and 
52.3% on the U.S. side. On the Canadian side 1,490 dead trees were counted 
whereas 1,236 dead trees were counted on the U.S. side of the boundary (Murtha, 
1972,). 
Since a number of studies have reported on the capability of photo 
interpretation to delineate bark-beetle caused tree—mortality and defoliator 
defoliation on medium-, and large scale photos, Ciesla (1974) reported on the 
use of ultra-small scale (1:126,720) for interpretation of the above noted 
damage types. Defoliation of ponderosa pine ( Pinus ponderosa Laws) forests by 
pine butterfly ( Neophasia Tnenapia ( F. & F.)) was readily noted on color—infrared 
positive transparencies. Photo interpretation of conifer mortality caused 
by mountain pine beetle ( Dendrootonus ponderosae Hopk.) was only partially 
successful. Western spruce budworm ( Choristoneura ocoidentalis Freeman) defol 
iation of current year’s foliage was not resolved on the ultra-small scale