MANUAL thus had the difficult task to offer highly 
flexible concepts while maintaining standards 
designed to ensure the temporal and geographical 
comparability of the inventory results even across 
national borders. 
4. SUMMARY OF CONTENTS 
The MANUAL consists of six chapters. The first 
three (Introduction, Color-Infrared-Film, Flight 
Parameters) elaborate on the basics of the proce- 
dure. The brief characterization and comparison of 
the various methods to monitor forest damages in 
field-work and remote sensing is followed by a 
description of the photographic features and use of 
CIR-films, the planning and actual taking of aerial 
photographs, and a detailled call for tender. 
The chapter "Inventory Concept" lists selection 
criteria and supplies inventory concepts along with 
sampling designs for inventory areas of various 
sizes, ranging from multistage sampling surveys to 
complete surveys of specific single stands. 
Furthermore methods are introduced which allow to 
locate identical trees in the photographs of 
follow-up- inventories. 
The quality of interpretation results, especially 
their reproducibility and comparability, is mainly 
dependent on standardized assessment methods and 
carefully developed interpretation keys. Hence 
chapter five entitled  "Photointerpretation" is 
particularly important. It contains the 
interpretation keys for the tree species spruce, 
pine, oak, beech and silver fir which have been 
developed by the international expert team 
"Arbeitsgruppe Forstlicher — Luftbildinterpreten" 
(AFL) over a period of several years (Verein 
Deutscher Ingenieure, 1990). Meanwhile the keys 
have proved to be worthwhile in a number of 
inventories which have been carried out in various 
countries (Gross, 1990). They distinguish five 
classes of "crown condition" in accordance to 
damages classified in terrestrial inventories. 
Another important characteristic of theses 
interpretation keys is that shape characteristics 
are equivalent to, or even more important, than 
colour characteristics (Gross et al. 1990). Due to 
the fact that the present interpretation keys do 
not cover the whole spectrum of tree species in 
European forests, the MANUAL supplies all informa- 
tion which necessary to compile additional inter- 
pretation keys on the basis of the AFL-keys. 
Chapter five is completed by recommendations for 
the organisation of interpretations, technical 
equipment used in the analysis, the training of 
interpreters and means of control during the 
evaluation. 
The final chapter six deals with the basics of the 
statistical data analysis. It emphasizes how 
important it is to handle information with utmost 
care which could only be obtained with great effort 
in the first place. In addition, this chapter draws 
attention to typical problems in forest damage 
inventories, outlines possible solutions and 
describes previously applied methods. It is a 
reminder that in all phases of the inventory, from 
the conception to data analysis and the 
presentation of the results, maximum care in the 
statistical planning and processing is 
indispensable to warrant the effectiveness and 
confidence of the inventory. 
248 
5. CONCLUSION 
With the publication of the EEC-Manual standard 
preliminaries to monitor the state of forests in 
Europe with remote sensing methods have been 
established. Professional applicants have now 
access to current research in a form which is both 
concise and practice-oriented. Although the MANUAL 
does not give (legally) binding directions for 
application, future inventories on the basis of 
aerial photographs will undoubtedly have to conform 
with its minimal standards. Most importantly, the 
application of the interpretation keys improves the 
standardisation of evaluation methods and provides 
the basis for comparison between different 
inventories. 
Yet the MANUAL does not settle inventory problems 
once and for all. Its "ring binding" underlines 
that further information from research or practical 
experience can be added at any time. For the 
present the MANUAL is available in English, French 
and German, but translations into other European 
languages will follow as the application becomes 
more widespread and the demand increases. 
6. REFERENCES 
COMMISSION OF THE EUROPEAN COMMUNITIES, 1991: 
Remote Sensing Applications for Forest Health 
Status Assessment. Edition by Hildebrandt, G.und 
Gross, C.P., Printed in Belgium by Walphot S.A. 
CONSTANTINI, B. 1990: Applicazione del telerileva- 
mento per l'osservazione dei danni alle foreste. 
Rapporto finale. Venezia 
GIOT, P. 1989: Apport de la télédétection au con- 
trole de l'etat sanitaire des forets de la 
Communaute. Rapport Final. Terrebois S.A.. 
GIOT-WIRGOT, P.; MARECHAL, P.; FELTEN, V. 1986: 
Evaluation de la télédétection comme méthode 
d'identification des troubles phytosanitaires en 
foret. Rapport final, Louvain 
GROSS, C.P. 1990: Die Anwendung der AFL-Interpreta- 
tionsschlüssel in den Ländern der Europäischen 
Gemeinschaft. VDI, Kommission Reinhaltung der Luft, 
Schriftenreihe Band 14, S.89-97 
GROSS, C.P.; HEIDINGSFELD, N. 1990: Interpretation 
of Colour-Infrafred Photographs for the Assessment 
of Forest Decline in Central Europe. In: Inter- 
national Archives of Photogrammetry and Remote 
Sensing, Volume 28, Part 7-1, ISPRS Commission VII, 
Proceedings of the Symposium on Global and 
Environmental Monitoring, Victoria, Canada, S.752- 
758 
HILDEBRANDT, G., GRUNDMANN, O., SCHMIDTKE, H., 
TEPASSE, P. 1986: Entwicklung und Durchführung 
einer Pilotinventur für eine permanente europäische 
Waldschadensinventur. Schriftenreihe des 
Kernforschungszentrums Karlsruhe, KfK-PEF 11 
HILDEBRANDT, G.; BURK, R.; GROSS, C.P.; MAXIN, J. 
1989: Beitrag von Fernerkundungstechniken zur 
Erfassung des Gesundheitszustandes der Europáischen 
Wälder. Schlußbericht, Teile A, B, C. Universität 
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