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The restoration of forest structure and function is increasingly being used in boreal forests in order to halt the loss of biodiversity. Often ecological restoration is aimed at increasing the volume of dead and dying trees to enhance the biodiversity of deadwood-dependent organisms, but it may also increase population sizes of pest bark beetle species, even several years following restoration. Herein, we used a large-scale restoration experiment in Northern Sweden to assess the 5 years post-restoration effects of restorative gap cutting and prescribed burning on the populations of a set of economically harmful pest bark beetles (Ips typographus , Polygraphus poligraphus , Tomicus piniperda and Pityogenes chalcographus) and the most important predators of bark beetles, Thanasimus spp. In addition, we assessed the effects of forest stand characteristics at stand and landscape scale on the abundance of I. typographus. Five years post-restoration, gap-cut stands supported the highest abundances of P. poligraphus and contained the highest count of spruce trees newly attacked by bark beetles. By contrast, prescribed burning generally sustained the lowest abundances of pest bark beetles, especially I. typographus and P. poligraphus , and the highest abundance of their natural predators Thanasimus spp. The population abundance of I. typographus was also positively affected by the area of clear cuts within a 500 m radius from the stand. In conclusion, prescribed burning appears to be a safer method for ecological restoration than gap cutting in the long-term. According to our results, a risk of a local bark beetle outbreak still remains 5 years following the initiation of ecological restoration treatments on spruce-dominated mature gap-cut stands. [ABSTRACT FROM AUTHOR]

Grafts from selected superior trees are used for establishment of seed orchards. These seeds result in trees with higher growth rates and better wood quality than trees originating from seeds collected in local forest stands., Insecticides are used to reduce damage to seeds in seed orchards. Hypothetically, this may be ineffective because the suppression of one insect species may relieve interspecific competition and trigger corresponding increases in damage caused by another species., Therefore, we investigated the effects of three insect species [ Dioryctria abietella Denis and Schiffermüller (Pyralidae), Cydia strobilella L. (Tortricidae) and Strobilomyia anthracina Czerny (Anthomyiidae)], singly and in all possible permutations, on the numbers and quality of seeds in Picea abies cones. Species were manipulated by insecticide treatments., The cones were examined for externally visible damage caused by D. abietella and S. anthracina after which the seeds were extracted, counted and X-rayed to assess seed quality and the number of seeds infested by insects. Finally, the cones were dissected to identify and count C. strobilella larvae., There was no evidence of trade-offs between absence of one species and increased damage by the remaining species. Instead, damage tended to increase as the number of species in a cone increased. The most serious pest species in the present study was D. abietella, reducing the number of filled seeds by approximately 60%. Our results indicate that there is little risk that suppression measures directed towards one particular species will lead to increased damage by other species. The insecticide, α-cypermethrin, showed promising results against D. abietella and S. anthracina. [ABSTRACT FROM AUTHOR]

Applying biogeographical insights to the regulation of production forestry and the determination of forest reserve strategies is expected to increase the effectiveness of biodiversity conservation actions. Here, we assess the extent to which such applications take place. By using Sweden as a case study, we demonstrate fundamental differences among biogeographical regions in natural patterns and processes, past land-use, and anthropogenic impacts that need to be better incorporated into strategic conservation planning and decisions. Furthermore, assessment of specific forestry regulations and biogeographical variation in a number of other countries/provinces embracing boreal and temperate biomes also indicate that natural boundaries are insufficiently considered in forest management policies. We suggest that a substantial potential exists to better align conservation priorities with biogeographical characteristics. To illustrate the application of such an approach, we present a decision support model on how forest conservation policies that rest on natural boundaries and ecological processes can be developed. [ABSTRACT FROM AUTHOR]