that date had many showy yellow flowers. 
However, infrared was much better for separ- 
ating Purshia tridentata from Artemisia tri- 
dentata (see color plate II B in accompanying 
paper by D. M. Carneggie). On the other hand, 
Carex exerta, a low-growing sedge, was only 
faintly visible in outline on color infrared in 
July when it was mature and dry; however, it 
stood out in a bright pink outline on June 10, 
when it was in a green vegetative stage. The 
two previously mentioned shrubs—both in 
early leaf stages—were not so easily distin- 
guished on June 10. The identification relation- 
ship between the two shrubs was similar at the 
Middle Park, Colo., test site. 
At the Black Mesa, Colo., test site, photo- 
graphs taken in July, when all herbaceous veg- 
etation was growing vigorously, provided mini- 
mum differentiation among species with either 
kind of film. However, by late August, when 
some species were completing their summer 
growth, species were more readily differentia- 
table. For example, Geranium fremontit, which 
had developed seed and leaves turning red, ap- 
peared gold in the color infrared photographs. 
No other image with this color characteristic 
was detected. Helenium hoopesii appeared as a 
pink rosette, brighter in the center than 
around the edges, on the color infrared. These 
and other species were not as easily identified 
in the color photographs (see color plate II C 
in accompanying paper by D. M. Carneggie). 
While it will take several conclusive photo 
interpretation tests to fully determine how 
much more useful one film type is over the 
other, we do have some indication that color 
infrared has distinct advantages in differen- 
tiating species. On three dates, for instance, 
Cirsium spp. consistently showed as unique 
brilliant red spots on color infrared. For the 
three dates, Purshia tridentata and Artemisia 
tridentata both appeared a very similar shade 
of green on color film, but on color infrared 
photos Purshia tridentata tended to be a brigh- 
ter red than Artemisia tridentata. A deer car- 
cass, which was placed along the flight line at 
the Kremmling, Colo., site, tended to show a 
brighter whitish tone on color infrared photo- 
graphs taken in August. Thus, it contrasted 
more with nearby vegetation than with the 
image characteristic on color film, thereby in- 
dicating the feasibility of this film type in as- 
sessing winter deer losses. 
This initial work with large-scale aerial 
photography has shown that many features— 
some surprisingly small—can be detected. A 
complete list of these detectable features would 
include the following: 
1. Individual shrub, grass, and forb plants. 
2. Flowers on forbs such as Eriogonum. 
192 
Larger seed heads on some grasses such 
as Bromus inermis. 
Colonies of tiny annuals such as Gayo- 
phytum spp. 
Cattle tracks and droppings. 
Soil surface erosion and surface mois- 
ture. 
Rocks as small as 1 or 2 inches in diam- 
eter. 
Dead deer and shed antlers. 
Rodent holes and casts. 
Anthills. 
POTENTIAL USES 
Because so many features can be seen on 
large-scale aerial photography, as compared to 
small-scale photography, prospects are good 
for developing techniques to: 
1. Identify many plant species and soil sur- 
face features. 
2. Better classify grass and shrub communi- 
ties into specific habitat types or sites. 
3. Measure herbaceous and shrub vegetation 
parameters such as cover, density, height, spa- 
tial distribution, and utilization. 
4, Monitor changes in vegetation and in soil 
surface conditions in relation to time. 
5. Monitor natural causal agents of vegeta- 
tion changes such as rodent, insect, and plant 
disease outbreaks; and livestock and big-game 
concentrations, etc. 
6. Increase the accuracy of interpretations 
made from small-scale surveillance systems, 
such as earth orbital satellite photography, or 
conventional small-scale aerial photography, 
within a multiple sampling procedure where 
interpretations from large-scale photography 
and ground truth (fig. 2) can be extrapolated 
to small-scale photography (see color plate I in 
accompanying paper by D. M. Carneggie). Fac- 
tors such as precipitation, wildfire, and plant 
die-off, which often occur uncontrolled over ex- 
tensive areas, could be monitored by such a 
system. 
7. Relate wildlife dynamics to habitat condi- 
tions. Also, by tying in early nighttime thermal 
sensing of campfires, hunter density and distri- 
bution might be related to big-game distribu- 
tions. 
8. Obtain early detection of situations which 
may have serious management implications, 
such as influx of noxious plants, unbalanced 
distribution of livestock, rodent concentrations, 
and environmental deterioration caused by rec- 
reational malpractice such as off-road vehicu- 
lar travel and littering near hunter camps. 
ADVANTAGES OF A PROVEN 
70-MM. SYSTEM 
An effective technique based on large-scale 
70-mm. aerial photography would have many 
Slo NA on . © 
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