Das Walderkrankungssyndrom im Gleinalmgebiet - Synopse der Ergebnisse

The Forest Decline Syndrome in the Gleinalm area - Synopsis of Results

Wien

1995

31 Lit. Ang.

Unselbständiges Werk

673

200032352

The forest decline syndrome in the Gleinalm area included yellowing of needles (of Norway spruce and silver fir), growth reduced, a high percentage of tree mortality in young trees and older age classes, root and stem rot and poor mykorrhiza. Studies concentrated on chemical analyses, of soil, air and needles, on increment, as well as on mykorrhizae, root and stem rots and some physiological parameters (electrical conductivity, deposition of nutrients in the xylem). Further, the stand history provided data on earlier stresses and treatments of the sites. The centire area suffered from cattle grazing, large-scale clear-cuts, surface burning and loss of biodiversity over a long period - until the middle of this century; forest management concentrated on monocultures of Norway spruce. The major part of present spruce stands suffer from stem rot after bark-peeling by red deer; in addition, root rot is common. Nitrogen deficiency ist the most common nutrition problem of the needles. The presence of air pollutants was proved, but the concentrations or rates of deposition seem to be too low for an explanation of the decline. Increment depressions have occurred since the late 1950ies or early 1960ies, the symptoms of the decline, however, became obvious as late as by the end of the 1970ies. This implies that visible symptoms became evident only after several very severe drought periods. The principal stress situation is caused by long-term excessive exploitation of the site and silvicultural treatment. Strategies of future forest management are discussed.