| 1. |
- Djupstrom, Line B., et al.
(författare)
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Density of dispersal sources affects to what extent restored habitat is used: A case study on a red-listed wood-dependent beetle
- 2024
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Ingår i: Forest Ecology and Management. - : ELSEVIER. - 0378-1127 .- 1872-7042. ; 555
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Tidskriftsartikel (refereegranskat)abstract
- When restoring habitats, an important question is whether the spatial distribution of habitat affects its contribution to biodiversity conservation. In Sweden, high-cut stumps are routinely created at forestry operations. By counting the number of exit holes of a red-listed beetle, Peltis grossa, we assessed occurrence, colonisations and extinctions per high-cut stump and beetle density per clear-cut. We found a threshold, at which the form of the relationship between density of the beetle and density of high-cut stumps per clear-cut changes abruptly. The beetle density was considerably higher where the density of high-cut stumps exceeded 4.5 per hectare. Such thresholds can be explained by colonisation-extinction processes. Observed colonisation-extinction dynamics were consistent with metapopulation theory. For instance, there was a positive relationship between colonisation rate and a connectivity measure that considered beetle abundance and distance for each high-cut stump in the surrounding area. However, the relationship disappeared when using a connectivity measure solely based on the distance of the high-cut stumps. The observed threshold implies that P. grossa benefits from aggregating the same total number of created high-cut stumps into fewer clear-cuts. This is because the total area with a density of high-cut stumps exceeding the threshold increases, and this expands the number and size of dispersal sources. Therefore, P. grossa and other species that reveal thresholds in their distribution patterns, are favoured when conservation measures are more spatially aggregated than what is resulting from current Swedish policy.
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| 2. |
- Gustafsson, Lena, et al.
(författare)
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Natural Versus National Boundaries: The Importance of Considering Biogeographical Patterns in Forest Conservation Policy
- 2015
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Ingår i: Conservation Letters. - : Wiley. - 1755-263X. ; 8, s. 50-57
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Gustafsson, Lena, et al.
(författare)
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Naturhänsyn vid avverkning – en syntes av forskning från Norden och Baltikum : en rapport från forskningsprogrammet Smart Hänsyn 2016
- 2016
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Rapport (populärvet., debatt m.m.)abstract
- En ny typ av naturvård har de senaste decennierna införts i svenskt skogsbruk. Vid alla skogsbruksåtgärder, och framförallt vid slutavverkning, måste hänsyn tas till den biologiska mångfalden. Det kan ske genom att medvetet välja ut och lämna enskilda träd och trädgrupper, att spara döda träd eller att skapa ny död ved med till exempel högstubbar. Hänsynen är angiven i skogsvårdslagen, men är också central inom ett certifierat skogsbruk, enligt såväl FSC som PEFC. Vad betyder naturhänsynen för de djur och växter som lever i skogen och kan man göra den ännu bättre? Vad säger egentligen forskningen? Inom forskningsprogrammet ”Smart Hänsyn” har vi försökt svara på dessa frågor genom att sammanfatta cirka 120 vetenskapligt granskade studier om naturhänsyn i norra Europa (Sverige, Norge, Finland och Baltikum). Vi har valt att begränsa oss till detta geografiska område eftersom länderna har likartade naturförhållanden och skogsbrukssätt. Urvalet är också begränsat till studier av naturhänsyn i det praktiska skogsbruket, och framför allt effekterna av hänsyn vid slutavverkning. En del stora, internationella översikter har också inkluderats. Baserat på studierna har vi gjort synteser över olika teman: kantzoner, hänsynsytor, högstubbar, död ved, asp, kostnadseffektivitet och internationella kunskapsöversikter. Syftet har varit att förmedla den stora kunskap som finns samlad inom forskningen till de som planerar och utför naturhänsyn i praktiken, till beslutsfattare på olika nivåer och till de som är allmänt intresserade av skog och miljö. Uppdraget att sammanfatta studierna gick till Silvinformation AB, där Yvonne Aldentun och Mats Hannerz har gjort huvuddelen av artikelsammanfattningarna. Synteserna har gjorts av oss som uppdragsbeställare. I de sju synteserna har vi gått ett steg vidare och försökt ge praktiska råd. Ibland är det samma råd som har getts i de artiklar som refereras, men oftare är det våra egna tolkningar baserat på den samlade kunskapen. Det är vår förhoppning att materialet ska kunna användas i undervisning och utbildning men också kunna fungera som underlag vid olika typer av utvärderingar och avvägningar. Vi hoppas också att sammanställningen ska inspirera fler forskare att presentera sina resultat på ett lättillgängligt sätt. Det är långtifrån alla som hinner följa flödet i de vetenskapliga tidskrifterna!
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| 4. |
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| 5. |
- Högbom, Lars, et al.
(författare)
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Trilemma of Nordic-Baltic Forestry-How to Implement UN Sustainable Development Goals
- 2021
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Forests are the dominant land cover in Nordic-Baltic countries, and forestry, the management of forests for improved ecosystem-service (ES) delivery, is an important contributor to sustainability. Forests and forestry support multiple United Nations Sustainability Goals (UN SDGs) and a number of EU policies, and can address conflicting environmental goals. Forests provide multiple ecosystem services and natural solutions, including wood and fibre production, food, clear and clean water and air, animal and plant habitats, soil formation, aesthetics, and cultural and social services. Carbon sequestered by growing trees is a key factor in the envisaged transition from a fossil-based to a biobased economy. Here, we highlight the possibilities of forest-based solutions to mitigate current and emerging societal challenges. We discuss forestry effects on forest ecosystems, focusing on the optimisation of ES delivery and the fulfilment of UN SDGs while counteracting unwanted effects. In particular, we highlight the trilemma of (i) increasing wood production to substitute raw fossil materials, (ii) increasing forest carbon storage capacity, and (iii) improving forest biodiversity and other ES delivery.
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| 6. |
- Komonen, Atte, et al.
(författare)
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Ips typographus population development after a severe storm in a nature reserve in southern Sweden
- 2011
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Ingår i: Journal of Applied Entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 135, s. 132-141
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale natural disturbances pose challenges for the management of protected areas and may have undesirable consequences for commercial plantations nearby. A storm, which felled nearly 10 000 m3 of spruce forest in the Osaby nature reserve in southern Sweden, allowed us to study the subsequent population development of the spruce bark beetle (Ips typographus L.). Two summers after the storm, an exceptionally high proportion (74%) of wind-felled trees had been successfully colonized by the bark beetle, and all living spruce trees had been killed. On standing trees, colonization density was three times higher, and reproductive success one-fourth, that on wind-felled trees. The negative relationship between colonization density and reproductive success indicates that intra-specific competition is one of the main mechanisms reducing I. typographus population growth when the beetles switch from wind-felled to standing trees after storm disturbances. Indeed, there was no significant difference in beetle production between wind-felled and standing trees. Furthermore, there were no differences in colonization density, reproductive success or production at different heights in standing trees; however, a higher proportion of the new adults emerged at the tree-tops rather than lower down before overwintering. Our results also demonstrate that a large proportion (ca. 50%) of the I. typographus population that developed in the storm-fell area apparently overwintered under the bark of standing trees.
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| 7. |
- Kärvemo, Simon, et al.
(författare)
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Forest restoration as a double-edged sword: the conflict between biodiversity conservation and pest control
- 2017
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 54, s. 1658-1668
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Tidskriftsartikel (refereegranskat)abstract
- 1. Forestry has markedly changed a large proportion of the world's boreal forests, often with negative effects on biodiversity. As a result, forest restoration is increasingly implemented to counteract the negative effects. However, restoration measures aimed at mimicking natural disturbance regimes could simultaneously increase the risk of unwanted negative effects, such as damage by forest pest species. This study compares the effect of two restoration methods (prescribed burning and gap-cutting), on both biodiversity conservation and pest control, to provide a basis for solutions to this potential conflict.2. Bark beetles are ideal for studying this conflict, as this group is both species-rich and contains notorious pest species. We conducted a unique, large-scale field experiment in which we compared the effect of two different restoration methods on the abundance, species richness and assemblage composition of bark beetles. In addition, we estimated uncontrolled tree mortality by the number of trees that died post-restoration.3. Beetles were divided in two groups, primary and secondary, the former with an ability to kill growing trees. Bark beetle diversity did not differ between treatment groups prior to restoration. However, after restoration, assemblage composition and primary bark beetle abundance differed between the treatments. Furthermore, species richness was higher in burned and gap-cut stands compared to reference stands4. The number of trees that died post-restoration was highest on burned sites, whereas no difference was found between gap-cut and reference stands. The number of dead trees was correlated with the number of primary beetles.5. Synthesis and applications. We demonstrate the potential for a conflict between forest restoration for biodiversity conservation and the potential risk for tree mortality caused by forest pests. This is likely to become a problem in many boreal forests; however, our results suggest that this conflict can be moderated by the choice of restoration method. The restoration method gap-cutting had a similar positive impact on bark beetle species richness as compared to the burning method, but did not as burning, increase tree mortality. Thus, in areas where there is an apparent risk for pest outbreaks, our data suggest that gap-cutting should be the chosen method to avoid an unwanted increase in tree mortality at the stand level.
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| 8. |
- Lindmark, Matilda
(författare)
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Increased resilience in managed boreal forests : Controlling damage by spruce bark beetle and moose in Sweden
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Most of the forests growing in Europe today have been planted, or heavily affected, by humans. This is because the forest industry provides crucial raw materials for diverse products, including timber, pulp and paper, cellulose-based substances and renewable energy sources. However, forest management has turned heterogenic natural forests into homogenous forest stands that are highly susceptible to various kinds of damage. This thesis focuses on moose (Alces alces L.) browsing and attacks by spruce bark beetle (Ips typographus L.), both of which cause large economic losses. Empirically, it is based on field experiments conducted in managed forests in Sweden. Moose browsing on vulnerable top shoots of young pines during wintertime is a substantial problem in northern Europe. My colleagues and I (hereafter we) found that extracts of spruce trees (which moose prefer less than pine) can act as efficient natural browsing repellents.Spruce bark beetles attack spruce (Picea abies) trees throughout Europe. Thus, we also evaluated the field behavior of the beetles exposed to non-host- and fungal volatiles in efforts to identify more efficient ways to protect susceptible spruce stands. In addition, we evaluated the predator:prey ratio between the beetles and Thanasimus predators in representative forest stands, to assist efforts to enhance the biological control of spruce bark beetles in managed forests. Finally, we investigated changes in bacterial communities in wood after attacks by spruce bark beetles to improve knowledge of their ecology.Changes in forest management regime are needed to increase structural and tree species diversity, and thus raise forests’ resilience and ability to cope with ongoing climate change. Results presented in this thesis indicate that changing forest management to increase the variation in tree species variation will enhance the resilience of managed forests, thereby reducing damaging by both moose and spruce bark beetle.
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| 9. |
- Rosenberg, Olle, et al.
(författare)
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Effects of different insect species on seed quantity and quality in Norway spruce
- 2015
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Ingår i: Agricultural and Forest Entomology. - : Wiley. - 1461-9555 .- 1461-9563. ; 17, s. 158-163
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Tidskriftsartikel (refereegranskat)abstract
- 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 Schiffermuller (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, -cypermethrin, showed promising results against D. abietella and S. anthracina.
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| 10. |
- Santaniello, Francesca, et al.
(författare)
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Climate impacts of retention forestry in a Swedish boreal pine forest
- 2018
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Ingår i: Journal of Land Use Science. - 1747-423X .- 1747-4248. ; 13, s. 301-318
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Tidskriftsartikel (refereegranskat)abstract
- The excessive simplification of forest structure associated with clear cutting can carry risks for biodiversity. Tree retention is an alternative practice that maintains greater structural diversity, but its effects on climate change impacts relative to conventional harvesting are largely unexplored. By integrating field measurements from 12 forest stands with modelling approaches, we investigated the post-harvest effects on radiative forcing of tree retention in a Swedish boreal pine forest. In the near-term, impacts from carbon fluxes and surface albedo were of the same order of magnitude but with opposite sign (warming for carbon and cooling for albedo), with a net warming effect. In the long-term, the net effect turns to cooling, as the forest becomes a strong carbon sink. Retention had a significant effect on climate in the near-term, where differences between the various retention levels are more evident. At increasing tree retention, warming impacts from carbon fluxes tend to decrease, but cooling contributions from surface albedo are less pronounced. Balancing these effects, we find a net climate warming that increases with tree retention.
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