Extensive insect damage areas at two levels of tree mortality (50% 
and 75%) were easily delineated from winter frames. Aerial sketch mapping 
of looper-killed areas on Anticosti Island was carried out by the Quebec 
Department of Lands and Forests in 1972 and light to severe tree mortality 
was reported for about 508 sq. miles (1315 km 2 ). The same mortality areas 
were measured from ERTS images and a slightly lower figure was obtained, 
488 sq. miles (1264 km 2 ). This latter insect damage is also easily detected 
on snow free ERTS frames, especially in band 7 (infrared) where it comes 
out in particularly dark tone. 
CONCLUSIONS 
Small-scale color-IR aerial photographs (especially the 
transparencies) of good quality have a surprising potential for forest 
cover type appraisal, particularly for detecting and mapping tree mortal 
ity after a severe insect outbreak. This study is based on visual 
examination of photos through a standard stereoscope. Even if the scale 
is always a limiting factor for mapping small units with precision, in 
many cases we feel that they should be used more often for forest surveys 
instead of conventional larger scale photos as they permit photo inter 
preters to examine a larger land area at one time and to identify forest 
features with a good level of precision. 
A study was initiated this year to evaluate the capability of 
registering various levels of defoliation caused by spruce budworm 
(Choristoneura fumiferama (Clem.)) with high altitude color-IR photos 
of two different scales (1:140000 and 1:70000 approximately). The areas 
being studied were photographed last summer. 
ERTS-I imagery shows promising possibilities for mapping broad 
vegetation cover types, and for monitoring at least severe insect damage 
to forests. 
REFERENCES 
Beaubien, J. and L. Jobin 
1974: ERTS-X imagery for broad mapping of forest damage and cover 
types of Anticosti Island. Can. Surv. 28:164-166. 
Ciesla, W.M., L.E. Drake and D.H. Wilmore 
1971: Color photos, aerial sprays, and the forest tent caterpillar. 
Photo. Eng. 37:867-873. 
Ciesla, W.M. 
1974: Forest insect damage from high-altitude color-IR photos. 
Photo. Eng. 40:683-689.