| 1. |
- 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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| 2. |
- 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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| 3. |
- Johansson, Therese, et al.
(författare)
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Long-term effects of clear-cutting on epigaeic beetle assemblages in boreal forests
- 2016
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 359, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- Management of boreal forests for timber production has caused changes in forest structures and disturbance regimes, which have influenced a wide range of organisms. The aim of this study was to evaluate how composition of epigaeic (ground-living) beetle assemblages is influenced by stand age and management history in a heavily managed boreal forest landscape. We compared the epigaeic assemblages among stands of three ages: (1) young (8-25 years) and (2) middle-aged (40-58 years) stands regrown after clear-cutting, and mature stands (80-130 years) that had been selectively cut historically but never clear felled. We sampled epigaeic beetles in each of 42 stands, using 10 pitfall traps during seven summer weeks. More than 9000 specimens were collected and identified. The assemblages in young stands differed from those in middle-aged and mature stands, both for the Staphylinidae (rove beetles) and all beetle families combined. Carabidae (ground beetles) composition differed between young and middle aged stands only, and assemblages of Curculionidae (weevils, bark beetles and allies) differed between young and mature stands only. Assemblages of Leiodidae (round fungus beetles) had similar composition in all three stand types. Considering all families, young stands generally harbored fewer species and lower abundances compared with middle aged and mature stands. However, the Leiodidae had similar species richness in all three stand types. The lack of differences in assemblage composition, species richness and abundance between middle aged and mature stands suggests that epigaeic beetle assemblages recolonize following clear-felling. However, our collections included large numbers of unique and usually rare species in mature stands, indicating that old forest is important for the conservation of epigaeic beetles. Furthermore, the lower abundance of these beetles in young stands indicates that an increasing proportion of young stands on managed landscapes will reduce the overall abundances of epigaeic beetle species, with potentially negative impacts on recolonization.
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| 4. |
- Johansson, Therese, et al.
(författare)
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Short-term responses of beetle assemblages to wildfire in a region with more than 100 years of fire suppression
- 2011
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Ingår i: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 4:2, s. 142-151
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Tidskriftsartikel (refereegranskat)abstract
- 1. Suppression of wildfires in boreal landscapes has become widespread and has seriously affected many fire favoured species. However, little is known about the response of organism assemblages to large wildfires in regions with a long history of effective fire suppression, such as Scandinavia.2. We studied the short-term effects of a >1600 ha wildfire on beetle assemblages in northern Sweden. The first summer after fire, beetles were sampled in 12 sites using 36 large window traps, half in old pine forest stands in the burned area and half in similar, but unburned control stands. The entire beetle assemblage and eight subgroups were analysed: saproxylics, non-saproxylics, moderately fire favoured, strongly fire favoured, fungivores, predators, cambium consumers and red-listed species.3. Species composition differed markedly between burned and unburned forests in all nine groups. Furthermore, beetle abundance was higher in the burned area for the entire assemblage and for saproxylics, both groups of fire favoured species, predators and cambium consumers. Species number was higher only for non-saproxylics, strongly fire favoured species and cambium consumers.4. Our results show that wildfire has rapid and strong effects on a wide range of beetles. However, we only trapped two individuals of fire-dependent beetles, which may suggest a lack of such species in the region, possibly due to >100 years of fire suppression. At the regional scale, the studied wildfire may potentially increase the abundance of these beetles after a longer period of reproduction in the burned area.
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| 5. |
- 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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| 6. |
- Löfroth, Therese, et al.
(författare)
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Responses of eight boreal flat bug (Heteroptera: Aradidae) species to clear-cutting and forest fire
- 2010
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Ingår i: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 14, s. 3-9
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Tidskriftsartikel (refereegranskat)abstract
- Boreal flat bugs include a high proportion of species that are considered negatively affected by forestry. Knowledge on the biology and habitat demands of individual species is generally limited. We examined the influence on flat bugs of stand-age and clear-cutting, comparing five classes of spruce stands. The five classes were: clear-cut, unthinned, and thinned (all three products of current clear-cutting forestry), mature managed and old-growth stands (these two had never been clear-cut). We also compared unburned and recently burned mature pine forest. Fire, but not stand age, had a pronounced effect on species richness and total abundance. Aradus depressus showed a significant association with older forest stands. Aradus betulae occurred only in clear-cuts and burned forest indicating that this species is favored by disturbance in general. Aradus lugubris, Aradus crenaticollis and Aradus brevicollis were found only in the burned forest. Aradus brevicollis has not previously been shown to be associated with fire.
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| 7. |
- Olsson, Jörgen, et al.
(författare)
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Landscape and substrate properties affect species richness and community composition of saproxylic beetles
- 2012
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Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 286, s. 108-120
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Tidskriftsartikel (refereegranskat)abstract
- Intensive forest management has dramatically reduced the area of old-growth forest in Fennoscandia. We examined if the proportion of old forest in a landscape affects species composition, richness and abundance of saproxylic beetles. We used tube-shaped window traps in five pairs of sites, selected so that the sites within each pair differed with respect to the proportion of old forest (>125 years) in the surrounding landscape. A landscape level inventory of the wood fungi Fomitopsis rosea, as a proxy for forest with high conservation values, was used to complement the data on old forests. In addition, to testing whether mycelia-colonised wood may attract saproxylic beetles, the tube-shaped window traps were baited with wood colonised by Fomitopsis pinicola or F. rosea. Old-forest-rich landscapes supported significantly more species and a higher abundance of saproxylic beetles than old-forest-poor landscapes. The analysis revealed a clear connection between the community composition of saproxylic beetles and the proportion of old forest and number of F. rosea fruiting bodies in the surrounding landscape (radius 3 km). The local landscape species pool thus appears to be important for the beetle species that are trapped since the composition of saproxylic beetles differed between the two landscape types. The effects of the different baits were less pronounced than the effect of landscape type, although species-specific responses to the two mycelia baits were observed. This indicates that volatiles from mycelia of wood-decaying fungi and the mycelial community may affect colonisation patterns of saproxylic beetles. Our results suggest that forest fragmentation and habitat loss have resulted in depauperate beetle faunas in old-forest-poor landscapes. Our results highlight the need to invoke a landscape scale approach for preserving biodiversity, in this case the need to maintain a sufficient proportion of forest with old growth characteristics in the managed landscape.
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| 8. |
- 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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| 9. |
- 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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| 10. |
- Felton, Adam, et al.
(författare)
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Keeping pace with forestry : Multi-scale conservation in a changing production forest matrix
- 2020
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 49:5, s. 1050-1064
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Tidskriftsartikel (refereegranskat)abstract
- The multi-scale approach to conserving forest biodiversity has been used in Sweden since the 1980s, a period defined by increased reserve area and conservation actions within production forests. However, two thousand forest-associated species remain on Sweden's red-list, and Sweden's 2020 goals for sustainable forests are not being met. We argue that ongoing changes in the production forest matrix require more consideration, and that multi-scale conservation must be adapted to, and integrated with, production forest development. To make this case, we summarize trends in habitat provision by Sweden's protected and production forests, and the variety of ways silviculture can affect biodiversity. We discuss how different forestry trajectories affect the type and extent of conservation approaches needed to secure biodiversity, and suggest leverage points for aiding the adoption of diversified silviculture. Sweden's long-term experience with multi-scale conservation and intensive forestry provides insights for other countries trying to conserve species within production landscapes.
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