REPORT OF COMMISSION VII 
  
KEY FOR THE IDENTIFICATION OF WILD VEGETATION TYPES IN THE 
TROPICAL PACIFIC AREA 
A Plants growing in swampy or poorly drained sites; subject See B 
to flooding. 
A Plants growing in well drained sites, rarely or never sub- See F 
Ject to flooding. 
B Plants with palm frond leaves. See C 
B Plants without palm frond leaves. See D 
C Leaves light in tone; rarely in distinct rosettes; all plants 
in elump of uniform height (about 10 ft.) ; without distinet 
flower stalks. Usually grow in compaet stands along stream 
banks near coast with roots submerged in brackish water. Nipa 
C Leaves dark in tone; in distinet rosettes; plants in same 
clump usually of variable height (10-30 ft.). Conspieuous 
white flower stalk frequently protrudes above center of 
rosette. Usually grow in rather open stands in areas sub- 
  
  
jeet to periodie flooding by fresh water. Sago 
D Grass of uniformly grey tone and with ''velvety^? texture 
resembling sugar cane; usually confined to stream banks. Wild Cane 
D Trees of variable tone and texture. See E A | 
  
  
AY A, CROPPED : 
L Dense undergrowth beneath trees; erown canopy of trees 
usually of variable height with frequent small openings 
where direct sunlight can strike ground. Common on steep Rain Forest 
slopes, along stream banks and at edge of clearings. with undergrowth 
L Very little undergrowth beneath trees; largest trees form 
almost continuous crown canopy which permits little or no 
direct sunlight to strike the forest floor. Rain Forest 
  
  
  
F1G. 9. Portion of a dichotomous type of photo-interpretation key. 
D. TERMINOLOGY SCALES FOR DESCRIBING PHOTO IMAGE CHARACTERISTICS: 
The terms used in a key for describing such photographic image character- 
istics as shape, tone, texture, pattern, etc., should be as precise as possible. 
With the increased emphasis on construction and use of photo-interpretation 
keys, this matter assumes great importance. The inadequacy of presently-used 
terminology is manifest when we consider the variety of meanings that each 
of the following terms commonly used in keys may connote to different readers: 
“grayish tone’’; ‘mottled texture’; ‘‘rounded shape’; ‘‘dissected pattern’’; 
"steep slope"; "moderately high density," etc. One solution to this difficulty 
would appear to lie in the development and use by interpreters of various 
"terminology scales" of the types described below: 
(1) Tone Scales. Tone refers to the brilliance with which light is reflected 
by an object. On conventional black-and-white photography, tone is registered 
in varying shades of gray. In describing the characteristic tone of certain photo- 
graphic images, it is helpful to make reference to a standard "gray scale" such 
as that shown in Figure 10 (Daehn, 1949). 
(2) Size Scales. Size relates to the surface or volume dimensions of an object. 
  
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