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was concluded that the method can compete with the application of aerial tables. At present, a 
special study is being made of the dune vegetation near Castricum (province of Noord Holland), 
using false color (Ektachrome-Infrared-Aero) film and panchromatic film, in order to specify 
the advantage of false color films for vegetation studies. More elaborate studies of particular 
interest are launched in cooperation with the Forest Research Station of the Netherlands. They 
relate mainly to Pinus silvestris and also to Populus sp. , and special test-fights, using infrared 
and false color film will be carried out for this purpose at a scale of 1/5. 000. The aim of the 
Pinus silvestris project is threefold : 
a) Improvement of the stands. When Pinus silvestris was planted on a large scale in the 
Netherlands, about a century ago, the seeds imported originated from many different parts of 
Europe. Part of the seeds produced trees not fully adapted to the climatological conditions in 
the Netherlands. A yellowish discoloring of the needle tops, usually towards the end of April, 
is characteristic for them. 
b) Estimation of the damage caused by the removal of litter. Litter is removed from some 
forests, especially in the southern part of the country. It is exported to Belgium where it is 
used as fertilizer in mushroom cultivation. Decline in tree-growth is the result and'finally the 
trees die after about 8 years. Early detection is most important. 
c) In some Pinus silvestris stands a fungus (Fomes annosus) occurs. In some instances up 
to 100 % of the trees are affected and show discolouring of the needles, particularly in summer. 
The Populus project relates to the early detection of diseased trees, which shed their 
leaves too early in the season. These flights have to be made in early September. 
The importance of false-colour aerial photography for the early detection of diseased 
trees is evident from STELLINGWERF’s studies of a forest area near Brussels, Belgium. 
P. J. D. VERSTEEGH wrote a short but interesting publication on the photo-interpretation 
methods developped at the Forestry Department of Surinam (ITC Publ. B. 34) "... 
En Hongrie : 
... "Actuellement, les recherches sont en cours à l’Institut des Forêts et de l’Industrie du 
Bois, sous la direction de M. GERENCSER. On fait des études efficaces quant aux analyses de 
tonalité des photographies et quant à l’emploi de celles-ci dans le domaine forestier en faisant 
des examens par densitométrie et par microphotométrie. On emploie aussi dans ce domaine le 
stéréopnatomètre pour les examens de la définition des diamètres de la cime, de la fermeture, 
de la hauteur des arbres, pour le nombre de tiges et des espèces d’arbres. On a fait des expé 
riences semblables avec le stéréotop, dans la Section de Photogrammétrie de l’Office Forestier. 
Outre ces travaux, on a fait des analyses très intéressantes pour examiner la corrélation entre 
le diamètre de la cime et le diamètre à la hauteur d’appui et aussi l’analyse de la déformation 
projective. (BAN J. BERDAR B. dr. BEZZEG L. SEBOR J. et TARMAS G. ). 
Dr. S. MIKE a employé aussi avec succès le stéréotop au cours de mesures d’inclinai 
son et de calibrage, pour les examens agricoles et forestiers, pour analyser l’érosion du sol, 
la défense du sol et pour faire l'analyse géomorphologique" ... 
En Australie : 
... "Black and white photographs continue to provide the major source of material for photo 
interpretation by the forest departments in all states and for land-use studies by C.S.I. R.O. in 
northen Australia. In New South Wales, pure infrared photography was used in 1964 in an 
attempt to separate conifers (e. g. Callistris sp) from hard-woods (Eucalyptus sp ), but results 
were no better than using panchromatic film and a minus blue filter. In Western Australia, the 
Director of Kings Park is using aerial photographs and mosaics for mapping vegetation systems. 
Also, in Australia, the universities are showing a greater interest in the study of photo- 
interpretation. Photographs are frequently used in relation to geomorphology, geography and 
forestry and sometimes plant ecology. At the School of Forestry, University of Melbourne, the 
spectral reflectance and geometric optics of vegetation is being examined and twin 70 mm