Remote Sensing in Assessment of Forest Dieback and in Regeneration Processes

摘要

Long-term and lasting human interference in forest ecosystems, together with changing climatic conditions in Central European mountain forests have resulted in the loss of equilibrium mechanisms and a resulting increase in susceptibility to ecological disturbances. As a result, Norway spruce forests have been subject to frequent bark beetle outbreaks since the 1990's. We report on two methods for estimating bark beetle outbreaks and regeneration process in spruce forests: analysis of Landsat satellite data to quantify the spatial distribution of forest decline under bark beetle outbreaks between 1985-2002; and an assessment of forest regeneration and recovery process from recent airborne hyperspectral, color IR and LiDAR data, and botanical surveys in sites that have undergone different forest management practices during and after forest decline. The results document a significant increase in the area of highly damaged and dead forest classes, from 1% in 1985 to 16% in 1998, and a decrease in the area of healthy and moderately damaged spruce classes from 73% in 1985 to 52% in 1998. Since 1998 tree decline has continued but regeneration has started. We find differences between plant species richness and trajectory of the regeneration process for forests with and without interventions.