Distribution of a bark beetle and its predator within and outside old growth forest reserves: No increase of hazard near reserves

摘要: To test the hypothesis that reserves create a hazard because pest insects are more abundant in unmanaged forest than managed forests, pheromone trapping of lps typographus was done within and outside two small old growth (Tallet Nyteboda) southern Sweden. Initially, 2 km perpendicular transects centered Tallet reserve did not show higher abundance 1986 1987. A second hypothesis, predators existed diverse ecosystem (giving fewer bark beetles) tested. An important predator beetles, Thanasimus formkarius, monitored with kairomone traps inside reserves, together prey 1989. The catches (Ips) showed same pattern as earlier. caught numbers, but opposite to predictions reserves.