Vegetation of Southeast Asia Studies of Forest Types 1963-1965

E. Ajreas under Cultivation - (13) Estate and permanent native
cultivation; (1*0 Shifting cultivation and associated
secondary growth,
F. Cleared Land - (15) Herbaceous growth and lalang - drained;
(16) Herbaceous growth subject to flood.
Identification of Tree Species in the United States; In a paper
presented in Washington, D» C., on March 25, 1963, Heller, Doverspike
and Aldrich (Research foresters, Forest Insect Laboratory, Forest
Service, U. S. Department of Agriculture, Boltsville, .Maryland) discussed
a study conducted near Ely, in July I960, and repeated in the
cummer of 1Q62, to determine the best film and scale combination for
identifying tree species. Forest photo interpreters, report the
authors, have recognized for some time their inability to identify
individual tree speci.es on small scale aerial photographs (1:15,8^0
or smaller). With experience and knowledge obtained by photo scrutiny,
interpreters can new separate forest stands into broad species
(lasses, but they can seldom determine the species of individual
tree images.
The terrain of the test site is rolling, interspersed with lakes
and was previously glaciated. Forests cover about 85 percent of
the land area. A boreal area was chosen for the study because fewer
species needed to be compared. Fourteen important tree species were
selected on 29 separate locations. Nineteen replieaces were taken
of 8 of the most important species, and fewer replicates of the other
o species. The trees involved were species of Abies; Acer, '^etula,
Larix, ricea, Pinus, Populus, Sorbus, and Thuja.
In gathering ground data, trees were identified in the field on
large-scale (1:1,000)black and white prints made f-'om color transparencies.
To prevent possible bias, ground identifications were
made by one of the authors who did not ttxke the interpretation test.
A detailed description was made of each tree species selected, including
d.b.h., weight, crown class, site class, and other associaled
features. Only dominant, codominant, and intermediate crown-cla&o
trees were included, since overtopped trees are not visible on air
photographs.
To collect air data, a Hulcher 70-mra camera with a 150-mm (5-91
inches) focal length lens wad used. The films used were: Super
Aiiscochrome (General Aniline and Film Corp.), with an ASA rating of
125 for color; and Plus X Aerographic (Eastman Kodak), with an AGA
rating of 80,for the black and white photographs.
Photographic scales were approximately 1:396G> 1:15$*, and
1:1168. Tnese scales correspond to units of area measurement commonly
used by forestrs in the United States. White panels were
placed on the ground to provide identification of each of the 29
-locations on the photos while the pictures were being taken.