Analysis of human impact on boreal vegetation around Monchegorsk, Kola peninsula, using automated remote sensing technique

The boreal vegetation of the sub-Arctic comprises more than 30% of the Earth's forest area and plays a major role in controlling the global environment. In the 20th century the boreal vegetation of Fennoscandia was significantly changed by heavy industrialisation leaving many forest areas damaged or dying. Due to severe climate conditions of the sub-Arctic such vegetation changes are traceable over long periods of time. This provides an opportunity to study all types of human impact on vegetation in time and to develop methods to monitor geographical and structural changes in the vegetation cover. Here we present the first part of a larger study in which we use the remote sensing technique to investigate the dynamics of the boreal vegetation in Fennoscandia in context of human impact. We have developed a novel method for an automated analysis and mapping of vegetation and of all types of human impact based on a single support-vector-machines classifier (for the whole area). Implemented with free and open source software the method uses Landsat TM and ETM+ band data (for which it automatically performs atmospheric correction) and a number of indices like NDVI, NBR, etc. The accuracy of the 16-class classification has been assessed using field data and literature sources and determined to be 74.1%. The method has been successfully applied to a study area around Monchegorsk, Kola peninsula, Russia, the most industrialised part of northern Europe. We have characterised all major types of human impact on the boreal forest and tundra vegetation performing the change detection analysis in an area of 1750 km(2) between 1986 and 2005. The analysis has confirmed industrial atmospheric pollutions as the primary type of human impact here. We have discussed the role of forest fires and uncovered temporal trends in the vegetation cover. We have found that during the 19 years covered by the study more than one third of all coniferous forest in the area was transformed primarily to wetland, deciduous forest and typical tundra vegetation. The success of the method in this area allows us to extend the study to the rest of Fennoscandia and look at large scale changes in the boreal vegetation cover.