ENTOMOLOGICAL ASPECTS REGARDING THE CONVE RSION OF MONTANE SPRUCE FORESTS IN CENTRAL-EUROPE

The last decades impressively demonstrated the extraordinary instabili ty of secondary stands of Norway spruce. New concepts of forest manage ment are now considered, mostly including the conversion of unnatural pure spruce forests to mixed or deciduous forests. Entomological probl ems are substantially touched by such approach to more natural conditi ons at least in two points: biodiversity and forest protection. Thus, forest entomology is challenged to assist forestry supplying construct ive expertise. This is particularly necessary with montane forests, wh ich require very differentiated considerations. A brief survey of the threatenings by insects, to which Norway spruce is exposed at differen t altitudes of the montane region, demonstrates the relief which can b e expected from forest conversions. The transitional stage bears speci al risks, since a temporary destabilization of forests may provoke exc essive damage also by insects. Reintroduction of admired or alternativ e tree species may be accompanied by new tree-specific pest problems. Within certain limitations, leaving dead trees for raising animal dive rsity in forests can be reconciled with the necessities of forest prot ection.