Forest ecosystem health assessment by exergy approach.

The plant cover is the main absorbing landscape surface. Morphological and biochemical changes in this surface are associated with the extraction of information from the environment, including the solar spectrum. Interaction of the solar radiation with vegetation is resulting as a new composition of the spectrum of outgoing radiation. The exergy of the solar radiation, reflected by the surface of forest ecosystem, has been calculated by using digital data, recorded by the remote sensing satellites. In the study this approach has been applied to the assessment of the forest ecosystem health in the North-East part of the Czech Republic on the base of Landsat TM and ETM data. Changes of exergy values indicated the changes in the forest ecosystem processes.