Dynamics of forest disturbance in central part of the Šumava mountains between 1985 and 2007 based on Landsat TM/ETM+ satellite data

Abstract

During the last more than twenty years, various types of forest disturbance (i.e. insect outbreak, clearcutting) occurred in the central part of the Šumava Mountains. The bark beetle (Ips typographus [L.]) outbreak in this region resulted in regional-scale spruce forest decay. Clear-cutting was done here to prevent further bark-beetle propagation in the buffer zones. Dynamics of the disturbance types has been analyzed by processing 15 satellite Landsat TMIETM+ scenes from the years 1985, 1987, 1989, 1990, 1992, 1994, 1995, 1996, 1998, 1999,2002,2003, 2004, 2006 and 2007. Supervised classification (Maximum Likelihood) was used to identify deforested areas. Classification proved that main forest disturbance in the Central Šumava Mountains occurred between 1995 and 1998, when the dispersion of the spruce bark beetle in forest stands accelerated. Total area of decayed spruce forests doc to bark beetle during the whole period was estimated at 1 763 ha, Out of jI I 013 ha in the Bavanan Forest NP, 749 ha in the Šumava NP. Total clear-cut areas reached more than 387 ha in the Šumava NP, whereas they only reached a total of 13 ha in the Bavarian Forest NP. Compared to published data, the results for both disturbance types are lower as they did not include the area to the east of the peak Luzný. The hnal disturbance model shows progress and dynamics of spruce bark beetle spreading in both national parks as well as the development of forest losses due to clear-cutting mainly in the Šumava NP