Geographical information systems and remote sensing in mapping and monitoring fire-altered forest

This work results from the urgent need to monitor the impact of forest fires on sensitive ecosystems such as the Mediterranean forest. It was done in order to examine forest vulnerability to global change and the extent to which changes in traditional land use patterns in Mediterranean Europe impact upon this vulnerability. These changes have recently affected the fire regime which in tum has led to an increase in the occurrence and destructiveness of wildfires in Southern Europe. The research aims to monitor the impact of fires upon the Mediterranean forest on the Greek island of Thasos and consequently, to estimate forest vulnerability to the changes mentioned above. The specific objectives of the research are: 1. To map recent and old burned areas accurately by using satellite images. 2. To accurately assess the area and wood volume affected by fire using a Digital Elevation Model (DEM) ofThasos and employing GIS analysis. 3. To monitor Pinus brutia forest and ecosystem regeneration using a combined approach involving GIS and Global Positioning System (GPS). 4. To understand the ways in which controlling factors influence existing patterns of Pinus brutia regeneration in Thasos. From the analysis the following were concluded : 1. Although different image processing techniques are necessary for the mapping of recent and old bums the use of satellite images ended in accurate burned area mapping. However, topographic correction of the satellite images prior to their use in the analysis improved the accuracy of mapping. 2. More than 70% of the area covered by Pinus brutia is estimated to have been affected by the fires. The Pinus brutia wood volume affected by the fires was 90% of the total. 3. Measurements of regeneration, eight to thirteen years after fire suggest that the Pinus brutia forest in Thasos is making a complete recovery. 4. Finally, controlling factors affect regeneration patterns in a complex hierarchical way. Understanding of critical values or thresholds in several of these factors is important to understand patterns of regeneration.Digitisation of this thesis was sponsored by Arcadia Fund, a charitable fund of Lisbet Rausing and Peter Baldwin