170 BULLETIN 1059, U. S. DEPARTMENT OF AGRlLTLTLRE. 
EXTERNAL FIELD OBSERVATIONS. 
At each station where the environment is being studied, one or 
more individual trees should be permanently marked and numbered. 
and their condition should be a matter of daily observation. The 
number of trees chosen will depend upon the composition of the 
stand. Where even-aged stands of one species are studied, probably 
two representative trees of the dominant and eodominant classes 
will be sufficient. In all-aged stands, at least three trees of various 
ages above reproduction should be included and two sets of such 
trees if the stand contains more than one prominent species, or if the 
site is being studied from the standpoint of more than one species. 
In studies of reproduction conditions, the smallest seedlings available 
should be under observation. 
In these external observations. Forest Service Form 416 may be 
used as a guide, since it covers comprehensively the ordinary phe- 
nological observations. A reduced copy of this form may well be 
kept in the field notebook, and the field observations may be given 
in the form of numbers corresponding to the captions of the " Phe- 
nological Observations " form. For example. " 1 " would lie used to 
indicate that buds were beginning to swell. 
As has been said, ocular observations on these common phenomena 
of growth, especially at the actual beginning of tree growth in the 
spring and its termination in the fall, are too crude. Some method 
of measuring and recording the actual growth from day to day is 
required. A number of auxometers might be mentioned, but a meter 
really adapted to plants in the field, and especially the exposed sway- 
ing tops of trees, has not been produced, so far as the writers know. 
There is unlimited field here for invention. 
Form 416. 
[U. S. Department of Agriculture.. Forest Service.] 
PHEXOLOGICAI. OBSERVATIONS. 
: ecies 
Period covered by observations 
Name of observer 
Residence -- 
i State, i (County.) (Town.) 
General character of country. — Mountains; foothills; plains; river valley; 
seacoast. 
Situation of trees. — Level; slope (north, cast. vest, south); hilltop; river hot- 
torn; soil {sandy, clayey, heavy, Ught, deep, shallow, moist, dry) ; forest; 
open ground; park; street. 
(Please check tne words which apply to >• ur particular locality ami to the trees 
observ. <1 1 
Approximate elevation above sea level 
Location of nearest Weather Bureau station 
State if season was wet or dry. early or late, etc- 
