24 
den: 
Sweden Thon 
Conifers can usually be clearly distinguished from deciduous trees by MCN 
means of infrared photographs. For other forestry purposes, however, The a 
these seem to be of less value than panchromatic photographs. It is still i UA 
not possible to distinguish pine and spruce with certainty, but experiments tained, 
with various filters and different sorts of film are now being made. ne | 
Finall 
U. S. A-: 1: 10.00€ 
nano are usec 
. : . ir : T 
In regions where the species mixture is simple as in the scuth and west of Te 
they can be done with scales of about 1:8.000 in softwood stands. be limit 
vantagec 
ground, 
while th 
Question No. 4: per hec 
Determination of height (trees, stand). One 
measu, 
Finland: the tre 
f : : coeffic 
The height of the stand was surveyed with stereomicrometer and paral- 
lax wedge at the experiment. The results were promising. 
France: Heig 
ments. 
The height of trees can be estimated by measuring their shadows on a heen u 
photograph. 2 mete 
Germany: to bet 
dt TUUM dis photog 
Relative estimation from stereoscopic pictures. Measurement of parallax. eos 
ments 
Italy: graphs 
(Question 4 and 5). The determination of height and volume was made 
after cartographic plotting in a stereocartograph Santoni 3° at the E.LR.A. 
(Officine Galileo, Florence). The relation between the scale of the plotting The 
and that of the map was usually kept within 2x — 4x. In the plotting and co 
instruments the experiments to measure the trees were executed according 
to the following methods: 
(1) for deciduous trees of the same age and for coniferous trees the 
profile method was used. Dete 
(2) For forests of high stems and different ages and for forests of Me- mentio 
diterranean type, the method of calculating the average value of the dif- manay 
ferent parts of one hectare was tried. of the 
measui 
When using the profile method the claims of the surveying were determined, and 
the profile-line of tbe ground and vegetation was then mechanically drawn in the plotting 
instrument. The volume of the tree was calculated through the known formulae, using a 
plottingcoefficient, determined by earlier observations on the ground. 
The experimental method of taking the average values of small parts within one hec- In 1 
tare, when dealing with high-stemmed or Mediterranean forests, was discovered by Dr. an exa 
Cosma. This method consists of an approximative calculation in a stereoscope of an d 
tograp! 
average developed zone within the boundaires of the stand, and a complete plotting of 
one hectare, chosen in this average developed zone. The circumferences of the trees are issued 
plotted as well as their individual height.