LARGE AREA OPERATIONAL EXPERIMENT FOR FOREST DAMAGE MONITORING IN EUROPE USING 
SATELLITE REMOTE SENSING - RESULTS OF THE TECHNICAL WORKING GROUP 
Mathias Schardt JOANNEUM RESEARCH, Graz 
Thomas Häusler, GAF Munich 
Hartmut Kenneweg, TU Berlin 
Herbert Sagischewski, TU Berlin 
KEY WORDS: 
Forest Damage, Monitoring, Standardisation, GIS, Landsat/TM, Aerial Photo Interpretation 
ABSTRACT: In January 1992, UNEP called the first Advisory Board meeting in Prague to launch the "Large Area 
Operational Experiment for Forest Damage Monitoring in Europe Using Satellite Remote Sensing" (LAOE). The 
Czech Republic, Poland and Germany agreed to participate by providing their relevant ongoing research projects as 
contributions to the experiment. The Czech Republic was nominated to be the lead country, and UNEP offered to 
provide co-ordination and secretarial services. The Advisory Board of the project appointed a Technical Working Group 
(TWG), with scientists from the Czech Republic, Poland, Finland and Germany to develop a methodology and prepare 
guidelines for the harmonisation of the various classification approaches for regional applications. The results and the 
recommendations of the TWG will be introduced in this paper. 
1. INTRODUCTION 
In the 1970's, a widespread deterioration in forest health 
was observed, first for the European fir and, 
subsequently, also for many other tree species. Now a 
large proportion of the forests in Europe is affected by 
forest decline to varying degrees. Intense research on 
the causes of this decline has been performed from that 
time on with the result that the decline can not be 
attributed to one single causal factor but rather is thought 
to be the result of a multitude of adverse environmental 
conditions (Hildebrandt, 1992; Skelly and Innes, 1994). 
Besides the fundamental research work a great variety of 
damage assessment methods have been developed, and 
numerous inventories have been carried out. In order to 
obtain reliable and comparable results on national and 
international level it has become necessary to monitor 
the forest damage by applying standardised inventory 
methods. 
Based on the Convention on Long Range-Transboundary 
Air Pollution of 1979, the "International Co-operative 
Programme on Assessment and Monitoring of Air 
Pollution Effects on Forests" (ICP-Forest) was 
established in 1985 by the Executive Body of the 
Convention. The work is based upon national monitoring 
inputs using terrestrial damage evaluation methods on 
sample points. The European governments are provided 
with statistics on forest condition on annual basis. This 
programme was funded by UNEP during 1985-1990. 
Since 1991, the countries finance the inventories 
themselves. 
Besides the statistics obtained through this national and 
transnational surveys, more detailed data is often 
required locally. Especially, there is a lack of spatial 
information of the damage distribution within the 
European Countries. The mapping of forest condition, 
displaying the spatial distribution of damage at national 
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and regional level, would be useful for determining the 
causes of forest decline and in improving the visualisation 
of damage statistics. 
Mapping of forest condition by the means of satellite 
remote sensing is a technology that should be 
considered as an additional tool for the ongoing work 
under the Convention. In various studies satellite remote 
sensing has been shown to improve the quality of forest 
change monitoring, and especially its reporting. Today 
the methodology is ready for large scale operational 
experiments, but not fully tested for regional damage 
monitoring. 
2. BACKGROUND 
The necessity to perform forest damage inventories 
arose with the occurrence of the first forest decline 
symptoms in large areas. The individual countries, 
participating in the LAOE, started from the beginning with 
research work and the establishment of damage 
assessment methods. These traditional methods are 
based on terrestrial sample surveys and partly 
accompanied by the interpretation of aerial photography. 
The approaches of the inventories, the area coverage 
and most of all the definition of damage classes varies 
widely among the countries. Despite of the immense 
costs and the lacks in providing maps, the biggest deficit 
is the inability to compare the results of these different 
damage assessments. 
The analysis of the literature shows that satellite remote 
sensing has been applied successfully in various forest 
decline mapping studies. Affected trees are characterised 
most conspicuously by discoloration and foliage loss, 
accompanied by leaf pigment, morphological and water 
content changes. It is generally acknowledged that these 
factors influence the spectral reflectance and that this 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996 
  
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