| 1. |
- Andersson, Jon, et al.
(författare)
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Defining stump harvesting retention targets required to maintain saproxylic beetle biodiversity
- 2016
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 371, s. 90-102
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Tidskriftsartikel (refereegranskat)abstract
- Stumps comprise up to 80% of the residual deadwood following clear cutting and are a significant source of biomass for bioenergetic applications. However, stump harvesting may pose significant conservation risks for saproxylic organisms that occur in residual deadwood. To define retention targets for stump harvesting operations, we compared abundance and species richness of saproxylic beetles within individual stumps as well as species accumulation curves in replicated pairs of clear cuts with and without stump harvesting in northern Sweden. Using 20 stands, we sampled 1049 stumps using eclector traps and collected 9821 beetles representing 253 species with known saproxylic biology. Nineteen of these species were red-listed in Sweden. We hypothesized that individual stumps left following stump harvesting would contain higher densities and species richness than in clear cuts without stump removal due to crowding of beetles into increasingly limited habitats. However, we found no difference in density or richness within individual stumps between control clear cuts and stumped stands. We also compared species richness between control and stumped treatments using rarefaction within individual stands and across all stands and found no difference. As with density and richness, beetle composition at the stand-level did not differ between control and stumped stands. Thus, the density of surrounding stumps within a stand had very little effect on beetle assemblages in residual stumps. We estimated the effect of stump harvest on species richness at the stand level by combining all samples and extrapolating a rarefaction curve derived from the landscape-level species pool to an accumulated sample volume of 48 m(3) which corresponds to the total volume of stumps on average-sized clear cuts in Northern Sweden. Using this curve, we compared differences in species richness in average-sized clear cuts with 100% (48 m(3)) and 25% (12 m(3)) stump retention and found that stump harvest resulted in a 26% (95% C.I. 7-41%) loss of species. While the absolute scaling of the landscape-derived rarefaction does not reflect species loss at the stand-level because the combined curve reflects all rare species in the landscape, the relative species loss derived from this curve may serve as credible benchmark for species loss at the stand level following current stump harvesting practices. This benchmark may be further calibrated with additional information on number of singleton species and estimates of maximum species richness. (C) 2016 Elsevier B.V. All rights reserved.
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| 2. |
- Andersson, Jon, et al.
(författare)
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Long-term effects of stump harvesting and landscape composition on beetle assemblages in the hemiboreal forest of Sweden.
- 2012
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Ingår i: Forest Ecology and Management. - Amsterdam : Elsevier. - 0378-1127 .- 1872-7042. ; 271, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- Studies on the effects of stump harvesting on forest biodiversity are scarce and studies on long-term effects are until now non-existent. We evaluated such long-term effects by sampling beetles at 14 clear-cuts with and 14 clear-cuts without stump harvesting; harvesting had been done 21–28 years before this study. By using window traps, we collected 6429 individuals belonging to 432 species in 55 taxonomic families. To control for potentially confounding effects of among-site variations in landscape setting we also assessed forest age and volume of deciduous trees within the forest surrounding each site. The long-term effects from harvesting on beetle abundance, species richness and species composition was generally small in comparison to the influence of the characteristics of the surrounding forests. The species richness of the beetle family Latridiidae and the functional group fungivores appeared, however, to be negatively affected by the previous stump harvesting, while several other groups showed strong associations to the characteristics of the surrounding forest. We found little support for considerable long-term effects of stump harvesting on beetles flying in the stands. Long-term effects of stump harvesting at the landscape scale accumulated from harvest of many localities may still be severe, and should be the subject of future studies.
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| 3. |
- Andersson, Jon, et al.
(författare)
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Short-term response to stump harvesting by the ground flora in boreal clearcuts
- 2017
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 32:3, s. 239-245
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Tidskriftsartikel (refereegranskat)abstract
- We studied short-term ground vegetation responses to stump harvesting by recording the occurrence of all species of bryophytes, vascular plants and the cover of soil disturbance on 20 clearcuts in the Southern and Middle Boreal zone in northern Scandinavia. All 20 clearcuts were slash-harvested and scarified and 10 of the clearcuts were also stump-harvested. The added effect of stump harvesting was assessed by comparing stump-harvested clearcuts with non-stump-harvested clearcuts. We tested whether stump harvesting causes extra soil disturbance compared to conventional forestry and if stump harvesting is affecting the assemblage, species richness and occurrence of individual species of vascular plants and bryophytes in boreal clearcuts. Our results revealed that stump harvesting causes an increase in the area of disturbed soil surface compared to conventional harvesting. Four of the most commonly occurring plant species in this area were significantly affected by stump harvesting, and Vaccinium vitis-idaea had a median occurrence of only 20% of that in non-stump-harvested clearcuts. The large impact on some plant species from a relatively modest increase of soil disturbance caused by stump harvesting suggest that stumps, with their slightly elevated bases, contributes to the survival of certain species on clearcuts.
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| 4. |
- Andersson, Jon, et al.
(författare)
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Wood-Inhabiting Beetles in Low Stumps, High Stumps and Logs on Boreal Clear-Cuts: Implications for Dead Wood Management
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- The increasing demand for biofuels from logging residues require serious attention on the importance of dead wood substrates on clear-cuts for the many forestry-intolerant saproxylic (wood-inhabiting) species. In particular, the emerging harvest of low stumps motivates further study of these substrates. On ten clear-cuts we compared the species richness, abundance and species composition of saproxylic beetles hatching from four to nine year old low stumps, high stumps and logs of Norway spruce. By using emergence traps we collected a total of 2,670 saproxylic beetles among 195 species during the summers of 2006, 2007 and 2009. We found that the species assemblages differed significantly between high stumps and logs all three years. The species assemblages of low stumps, on the other hand, were intermediate to those found in logs and high stumps. There were also significant difference in species richness between the three examined years, and we found significant effect of substrate type on richness of predators and fungivores. As shown in previous studies of low stumps on clear-cuts they can sustain large numbers of different saproxylic beetles, including red-listed species. Our study does, in addition to this fact, highlight a possible problem in creating just one type of substrate as a tool for conservation in forestry. Species assemblages in high stumps did not differ significantly from those found in low stumps. Instead logs, which constitute a scarcer substrate type on clear-cuts, provided habitat for a more distinct assemblage of saproxylic species than high stumps. It can therefore be questioned whether high stumps are an optimal tool for nature conservation in clear-cutting forestry. Our results also indicate that low stumps constitute an equally important substrate as high stumps and logs, and we therefore suggest that stump harvesting is done after carefully evaluating measures to provide habitat for saproxylic organisms.
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| 5. |
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| 6. |
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| 7. |
- Angelstam, Per, et al.
(författare)
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Evidence-Based Knowledge Versus Negotiated Indicators for Assessment of Ecological Sustainability : The Swedish Forest Stewardship Council Standard as a Case Study
- 2013
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42:2, s. 229-240
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Tidskriftsartikel (refereegranskat)abstract
- Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards' ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC's ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process.
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| 8. |
- Axelsson, Petter, et al.
(författare)
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Can leaf litter from genetically modified trees affect aquatic ecosystems?
- 2010
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Ingår i: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 13:7, s. 1049-1059
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Tidskriftsartikel (refereegranskat)abstract
- In addition to potential benefits, biotechnology in silviculture may also be associated with environmental considerations, including effects on organisms associated with the living tree and on ecosystems and processes dependent on tree residue. We examined whether genetic modification of lignin characteristics (CAD and COMT) in Populus sp. affected leaf litter quality, the decomposition of leaf litter, and the assemblages of aquatic insects colonizing the litter in three natural streams. The decomposition of leaf litter from one of the genetically modified (GM) lines (CAD) was affected in ways that were comparable over streams and harvest dates. After 84 days in streams, CAD-litter had lost approximately 6.1% less mass than the non-GM litter. Genetic modification also affected the concentration of phenolics and carbon in the litter but this only partially explained the decomposition differences, suggesting that other factors were also involved. Insect community analyses comparing GM and non-GM litter showed no significant differences, and the two GM litters showed differences only in the 84-day litterbags. The total abundance and species richness of insects were also similar on GM and non-GM litter. The results presented here suggest that genetic modifications in trees can influence litter quality and thus have a potential to generate effects that can cross ecosystem boundaries and influence ecosystem processes not directly associated with the tree. Overall, the realized ecological effects of the GM tree varieties used here were nevertheless shown to be relatively small.
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| 9. |
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| 10. |
- Axelsson, Petter, et al.
(författare)
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Leaf litter from insect-resistant transgenic trees causes changes in aquatic insect community composition
- 2011
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Ingår i: Journal of Applied Ecology. - Malden : Wiley-Blackwell. - 0021-8901 .- 1365-2664. ; 48:6, s. 1472-1479
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Tidskriftsartikel (refereegranskat)abstract
- 1. Recent research has addressed how transgenic residues fromarable crops may influence adjacent waterways, aquatic consumers and important ecosystem processes such as litter breakdown rates. With future applications of transgenic plants in forestry, such concerns may apply to forest stream ecosystems. Before any large-scale release of genetically modified (GM) trees, it is therefore imperative to evaluate the effects of genetic modifications in trees on such ecosystems. 2. We conducted decomposition experiments under natural stream conditions using leaf litter from greenhouse grown GM trees (Populus tremula x Populus tremuloides) that express Bacillus thuringiensis (Bt) toxins (cry3Aa; targeting coleopteran leaf-feeding beetles) to examine the hypothesis that GM trees would affect litter decomposition rates and/or the aquatic arthropod community that colonizes and feeds on leaf litter in streams. 3. We show that two independent transformations of isogenic Populus trees to express Bt toxins caused similar changes to the composition of aquatic insects colonizing the leaf litter, ultimately manifested in a 25% and 33% increases in average insect abundance. 4. Measurements of 24 phenolic compounds as well as nitrogen (N) and carbon (C) in the litter did not significantly differ among modified and wild-type trees and were thus not sufficient to explain these differences in the insect assemblage. 5. Decomposition rates were comparable among litter treatments suggesting that the normal suite of leaf traits influencing decomposition was similar among litter treatments and that the shredding functions of the community were maintained despite the changes in insect community composition. 6. Synthesis and applications. We report that leaf litter from GM trees affected the composition of aquatic insect communities that colonized litter under natural stream conditions. This suggests that forest management using GM trees may affect adjacent waterways in unanticipated ways, which should be considered in future commercial applications of GM trees. We also argue that studies at different scales (e.g. species, communities and ecosystems) will be needed for a full understanding of the environmental effects of Bt plants.
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| 11. |
- Axelsson, Petter, et al.
(författare)
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Leaf ontogeny interacts with Bt modification to affect innate resistance in GM aspens
- 2011
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Ingår i: Chemoecology. - : Springer Science and Business Media LLC. - 0937-7409 .- 1423-0445. ; 21:3, s. 161-169
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Tidskriftsartikel (refereegranskat)abstract
- Bioassays with a non-target slug (Deroceras spp.) and chemical analyses were conducted using leaf tissue from already existing genetically modified insect-resistant aspen trees to examine whether genetic modifications to produce Bacillus thuringiensis (Bt) toxins could affect plant phytochemistry, which in turn might influence plant-herbivore interactions. Three major patterns emerged. First, two independent modifications for Bt resistance affected the phytochemical profiles of leaves such that both were different from the isogenic wild-type (Wt) control leaves, but also different from each other. Among the contributors to these differences are substances with a presumed involvement in resistance, such as salicortin and soluble condensed tannins. Second, bioassays with one Bt line suggest that the modification somehow affected innate resistance ("Innate" is used here in opposition to the "acquired" Bt resistance) in ways such that slugs preferred Bt over Wt leaves. Third, the preference test suggests that the innate resistance in Bt relative to Wt plants may not be uniformly expressed throughout the whole plant and that leaf ontogeny interacts with the modification to affect resistance. This was manifested through an ontogenetic determined increase in leaf consumption that was more than four times higher in Bt compared to Wt leaves. Our result are of principal importance, as these indicate that genetic modifications can affect innate resistance and thus non-target herbivores in ways that may have commercial and/or environmental consequences. The finding of a modification-ontogeny interaction effect on innate resistance may be especially important in assessments of GM plants with a long lifespan such as trees.
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| 12. |
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| 13. |
- Axelsson, Petter, et al.
(författare)
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Tolerance and growth responses of populus hybrids and their genetically modified varieties to simulated leaf damage and harvest
- 2012
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 276, s. 217-223
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Tidskriftsartikel (refereegranskat)abstract
- Our results give a strong indication that the growth responses of the GM varieties to leaf damage and harvest were substantially equivalent with their corresponding non-GM varieties. These similarities predict that the effect of damage on production should be alike regardless of if the GM or non-GM products are used. (C) 2012 Elsevier B.V. All rights reserved.
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| 14. |
- Bell, David, et al.
(författare)
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Forest restoration to attract a putative umbrella species, the white-backed woodpecker, benefited saproxylic beetles
- 2015
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Ingår i: Ecosphere. - 2150-8925 .- 2150-8925. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- Umbrella species are often spatially demanding and have limited ability to adapt to environmental changes induced by human land-use. This makes them vulnerable to human encroachment. In Sweden, broadleaved trees are disadvantaged by forestry, and commercially managed forests are often deprived of dead wood. This has led to a situation where previously widespread top predators in saproxylic food webs, such as the white-backed woodpecker (Dendrocopos leucotos), have become species of conservation concern. The white-backed woodpecker is generally considered an umbrella species, and it has been linked to forests with large volumes of dead wood from broadleaved trees. In recent years, forest stands have been restored for the white-backed woodpecker, but post-treatment evaluations have rarely included other species that also occur in broad-leaved forests (co-occurring species). Many co-occurring species are saproxylic beetles. In this study, we collected saproxylic beetles and environmental data in restored and commercially managed forests to evaluate if habitat restoration for the white-backed woodpecker also benefited other species with similar habitat associations. We found that volumes of coarse woody debris were higher in restored than in commercially managed forests, and that a majority of man-made snags and downed logs were created from birch trees (Betula spp.). Most spruce trees (Picea abies) were extracted during forest restoration, and this opened up the forest canopy, and created stands dominated by broadleaved trees. Many saproxylic beetles were more common in restored forests, and there were significant differences in species composition between treatments. These differences were largely explained by species traits. Effects of sun-exposure were particularly important, but many beneficiary species were also linked to dead wood from broadleaved trees. Red-listed saproxylic beetles showed a similar pattern with more species and individuals in restored sites. The white-backed woodpecker is still critically endangered in Sweden, but important prey species are already responding to forest restoration at the stand level. We recognize that landscape-level improvements will be required to bring the white-backed woodpecker back, but also that the umbrella species concept can provide a useful framework for successful forest restoration as many co-occurring saproxylic beetle species seemingly benefitted from restoration for the white-backed woodpecker.
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| 15. |
- Bergmark, Paulina, et al.
(författare)
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Trait-environment interactions of saproxylic beetles as a guide to biodiversity conservation strategies
- 2024
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Ingår i: Journal of Environmental Management. - 0301-4797 .- 1095-8630. ; 360
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Tidskriftsartikel (refereegranskat)abstract
- Conservation of biodiversity requires in-depth knowledge of trait-environment interactions to understand the influence the environment has on species assemblages. Saproxylic beetles exhibit a wide range of traits and functions in the forest ecosystems. Understanding their responses to surrounding environment thus improves our capacity to identify habitats that should be restored or protected. We investigated potential interactions between ecological traits in saproxylic beetles (feeding guilds and habitat preferences) and environmental variables (deadwood, type and age of surrounding forest). We sampled beetles from 78 plots containing newly created high stumps of Scots pine and Silver birch in boreal forest landscapes in Sweden for three consecutive years. Using a model based approach, our aim was to explore potential interactions between ecological traits and the surrounding environment at close and distant scale (20 m and 500 m radius). We found that broadleaf-preferring beetle species are positively associated with the local broadleaf-originated deadwood and broadleaf-rich forests in the surrounding landscapes. Conifer-preferring species are positively associated with the local amount of coniferous deadwood and young and old forests in the surrounding landscape. Fungivorous and predatory beetles are positively associated with old forests in the surrounding landscapes. Our results indicate that both local amounts of deadwood and types of forests in the landscape are important in shaping saproxylic beetle communities. We particularly highlight the need to increase deadwood amounts of various qualities in the landscape, exempt older forests from production and to increase broadleaf-rich habitats in order to meet different beetle species' habitat requirements. Trait responses among saproxylic beetles provide insights into the significance of broadleaf forest and dead wood as essential attributes in boreal forest restoration, which helps conservation planning and management in forest landscapes.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Dynesius, Mats, et al.
(författare)
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Bryophyte species composition at the stand scale (1 ha) – Differences between secondary stands half a century after clear-cutting and older semi-natural boreal forests
- 2021
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 428
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Tidskriftsartikel (refereegranskat)abstract
- A growing proportion of the boreal biome consists of managed even-aged secondary forest stands regenerated after clear-cutting. Many disturbance-intolerant species may not be able to recolonize or reach their original abundance in these stands before the next clear-cutting, potentially causing large-scale biodiversity losses. Boreal bryophytes (mosses and liverworts) include many species intolerant to clear-cutting, and at small spatial scales species richness and occupancy has been shown to remain changed in secondary stands half a century after logging. To assess if such persistent changes occur also at the stand scale, we listed and estimated cover of all bryophyte species in 1-ha plots, comparing 14 secondary stands originating from clear-cutting 40–60 years earlier with 14 older semi-natural stands. The large plots also made it possible to assess differences in occupancy and abundance for more bryophyte species than in previous studies. Species composition differed significantly for both mosses and liverworts, but unlike earlier studies, we could not detect any significant difference between stand types in species numbers. Thirteen species were significantly associated with semi-natural stands and the total cover of liverworts was less than half in secondary stands. Secondary stands had significantly fewer species typically occurring under shady conditions and/or mostly growing on “tree substrates” (dead wood and/or bases and stems of living trees). Ordination analysis further emphasized the importance of shade and suitable deadwood substrates; the among-plot variation in bryophyte species composition was related to amount of coarse deadwood as well as to gradients from shady spruce dominated to open pine dominated stands and from polar- to equator-facing slopes. Besides lack of suitable habitat conditions in secondary stands, dispersal limitation may have caused a colonization time lag for some species. The clear importance of stand scale habitat conditions for bryophyte species composition calls for management adaptions to facilitate life boating and/or recolonization by ensuring availability of shade, coarse decomposing logs, and specific deciduous tree species (Populus, Salix, Sorbus) in secondary stands.
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| 20. |
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| 21. |
- Eggers, Sönke, et al.
(författare)
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Ecological restoration in boreal forest modifies the structure of bird assemblages
- 2017
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 401, s. 75-88
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Tidskriftsartikel (refereegranskat)abstract
- Ecological restoration is increasingly recognised as a useful tool for biodiversity conservation in boreal forests. Most restoration methods in this environment aim to emulate natural disturbances, and thereby promote the development of key ecological structures. However, research about forest ecosystem restoration is still in its infancy and the responses of many boreal species groups remain to be described. We established a large-scale field experiment to evaluate the short-term effects of two restoration treatments - prescribed burning and gap cutting involving the creation of dead wood - on breeding bird assemblages in boreal Sweden. We censused breeding birds using territory mapping during two years in forest stands subjected to the two restoration treatments, in untreated controls and in old-growth references (nature reserves) (n = 10 per treatment). Averaged over the two census years, we found 1145 territories of 36 bird species. Total bird species richness and abundance did not differ among treatments. However, prescribed burning led to clear changes in the structure of the bird assemblages. When dividing species according to four functional categorizations (migration, foraging, nesting and successional stage), we found that the abundance of long-distance migrants, ground breeders, strong cavity excavators and species preferring early-successional habitat was higher in burned stands than in untreated controls and gap-cut stands, as was the species richness of bark feeders and strong cavity excavators. In contrast, abundance of off-ground breeders and species richness of crown feeders were lower following prescribed burning than in the controls. The gap cutting treatment did not have any significant effects on the bird assemblages. Ecological restoration through prescribed burning can be a useful tool for the conservation of boreal forest birds, including the ecologically important strong cavity excavators (i.e. woodpeckers (Picidae)). Forest managers should therefore be encouraged to use prescribed burning as a restoration tool to quickly provide habitat for bird species adapted to natural disturbances in boreal forest. (C) 2017 Elsevier B.V. All rights reserved.
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| 22. |
- Ekholm, Adam, et al.
(författare)
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Long-term yield and biodiversity in stands managed with the selection system and the rotation forestry system: A qualitative review
- 2023
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 537
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Forskningsöversikt (refereegranskat)abstract
- There is an increasing interest in implementing Continuous Cover Forestry (CCF) as a tool to mitigate negative effects of the traditional rotation forestry system on biodiversity. However, the effects of CCF on forest growth and yield and on biodiversity is still poorly known. In this qualitative review, we compare biodiversity and longterm yield between the selection system, which is a type of CCF practiced in full-storied forests, and the traditional rotation forestry system. We specifically focus on forests dominated by Picea abies, which is a tree species of high economic relevance. Our literature search resulted in 17 publications on stand growth and yield and 21 publications on biodiversity. A majority of simulation studies found a higher long-term yield in the rotation forestry system, but it is challenging to conclude which system is the most productive. The magnitude of the difference in yield between systems, and how it varies across different environmental conditions, remains to be determined. For biodiversity, comparisons of species assemblage and individual species were only made to certain phases of the rotation cycle (recent clearcuts and middle-aged stands). Nevertheless, two aspects can be highlighted: i) the species assemblage in clearcuts differ substantially from stands managed with the selection system. Some of these effects may however be short lasting as examplified by studies on beetle assamblages showing that middle-aged rotation forestry stands become more similar to stands managed with the selection system, ii) the selection system maintains a similar species assemblage as the uncut control during the first years after cutting. In conclusion, management with the selection system may come with a loss in long-term stand yield, but much of the species assemblage is maintained after logging. We recommend future studies to specifically focus on long-term effects on biodiversity - in particular on species of conservation concern. There is also a need to establish a long-term research infrastructure to further develop the field.
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| 23. |
- Ekholm, Adam, et al.
(författare)
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Short-term effects of continuous cover forestry on forest biomass production and biodiversity: Applying single-tree selection in forests dominated by Picea abies
- 2022
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Ingår i: AMBIO: A Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 51, s. 2478-2495
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Tidskriftsartikel (refereegranskat)abstract
- The rotation forestry system provides high biomass production, but could also have a negative impact on species sensitive to disturbance. Continuous cover forestry (CCF) could contribute to solving these conflicting goals, but its feasibility in nutrient limited boreal forests is yet unresolved. In a unique experiment, we simultaneously assessed the short-term effect of single-tree selection on both biomass production and biodiversity (vascular plants, bryophytes, wood-inhabiting fungi), and tested fertilization as a way to mediate growth-biodiversity trade-offs. We found that unharvested stands and stands subjected to single-tree selection had a similar species assemblage of vascular plants, bryophytes, and wood-inhabiting fungi. Fertilization increased growth by 37% and induced shifts in two understory species (favoring the grass Avenella flexuosa and disfavoring the bryophyte Hylocomium splendens). We conclude that single-tree selection may become a useful tool to enhance biodiversity in managed forests.
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| 24. |
- Espinosa del Alba, Clara, et al.
(författare)
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Restoration strategies in boreal forests: Differing field and ground layer response to ecological restoration by burning and gap cutting
- 2021
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 494
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Tidskriftsartikel (refereegranskat)abstract
- The boreal biome is one of the largest in the world and its forests have been widely exploited for centuries. Consequently, large areas have suffered ecological simplification and loss of biodiversity. Under the current circumstances passive conservation measures are no longer enough and active restoration techniques need to be developed and assessed to preserve and recover the loss of biodiversity. We evaluated short- and long-term effects of two restoration methods aimed at mimicking natural disturbances on species richness, Shannon Diversity and community composition of vascular plants in the field layer and bryophytes in the ground layer. The experiment consisted of 18 forest stands in northern Sweden; each assigned to a different treatment: prescribed burning, gap cutting and untreated stands left as controls. A before-after control-impact (BACI) study design was applied and data was collected on three occasions: once prior to restoration (2010) and twice post restoration; one year (2012) and eight years after (2019). We analysed the differences in species richness and Shannon Diversity with linear mixed effect models and community composition changes with multivariate methods. Fire treatment caused an initial decline in diversity for both field and ground layer, but in the long-term, field layer surpassed the species richness and Shannon Diversity values found prior to restoration. Ground layer bryophytes species richness and Shannon Diversity remained lower than pre-treatment. Prescribed burning should, therefore, be used with caution in core areas for bryophyte diversity. Community composition in burned stands differed significantly between each time point as well as when compared to other treatments, for both layers. By contrast, we found no significant differences in diversity measures or community composition after gap cutting. The absence of effects from gap cutting suggests that minor changes in canopy cover does not affect the vegetation structure of forest stands. The organism group-specific responses, and temporal variability to restoration, highlight the importance of including more than one organism group, different restoration methodologies, and long-term studies in order to properly assess restoration outcomes at landscape level.
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| 25. |
- Felton, Adam, et al.
(författare)
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How climate change adaptation and mitigation strategies can threaten or enhance the biodiversity of production forests: Insights from Sweden
- 2016
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 194, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic climate change is altering the management of production forests. These changes are motivated by the need to adapt to the uncertainties and risks of climate change, and by the need to enlist their carbon storage and sequestration capacity as part of global mitigation efforts. These changes do however raise concerns regarding the potential implications for forest biodiversity. Here we evaluate these concerns by assessing the biodiversity implications of climate change adaptation and mitigation strategies (CCAMS) being implemented in the production forests of Sweden. We do so by identifying biodiversity goals aimed specifically at closing the existing gap between the habitat requirements of forest-dependent species, and the conditions provided by production forests, in terms of tree species composition, forest structures, and spatio-temporal forest patterns. We then use the existing literature to determine whether and by which pathway each CCAMS is likely to bridge or extend this gap. Our results indicate that CCAMS will often come into direct or partial conflict with Swedish biodiversity goals in production forests. Furthermore, some CCAMS which are inconsistent with biodiversity goals, such as logging residue removal, are being implemented more extensively than those which were most consistent with biodiversity goals. We nevertheless challenge the necessity of setting the preservation of forest biodiversity against climate change mitigation and adaptation. We clarify how CCAMS with negative biodiversity implications may still be implemented without adverse outcomes, if coupled with conservation interventions, or combined with other CCAMS deemed complementary in habitat provision. (C) 2015 Elsevier Ltd. All rights reserved.
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