| 1. |
- Angelstam, Per, et al.
(author)
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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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In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42:2, s. 229-240
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Journal article (peer-reviewed)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.
(author)
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Forest restoration to attract a putative umbrella species, the white-backed woodpecker, benefited saproxylic beetles
- 2015
-
In: Ecosphere. - 2150-8925 .- 2150-8925. ; 6:12
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Journal article (peer-reviewed)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.
(author)
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Long-term effects of clear-cutting on epigaeic beetle assemblages in boreal forests
- 2016
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 359, s. 65-73
-
Journal article (peer-reviewed)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.
(author)
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Short-term responses of beetle assemblages to wildfire in a region with more than 100 years of fire suppression
- 2011
-
In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 4:2, s. 142-151
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Journal article (peer-reviewed)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.
(author)
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Forest restoration as a double-edged sword: the conflict between biodiversity conservation and pest control
- 2017
-
In: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 54, s. 1658-1668
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Journal article (peer-reviewed)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.
(author)
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Responses of eight boreal flat bug (Heteroptera: Aradidae) species to clear-cutting and forest fire
- 2010
-
In: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 14, s. 3-9
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Journal article (peer-reviewed)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.
(author)
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Landscape and substrate properties affect species richness and community composition of saproxylic beetles
- 2012
-
In: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 286, s. 108-120
-
Journal article (peer-reviewed)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.
(author)
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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
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 428
-
Journal article (peer-reviewed)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.
(author)
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Ecological restoration in boreal forest modifies the structure of bird assemblages
- 2017
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 401, s. 75-88
-
Journal article (peer-reviewed)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.
(author)
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Keeping pace with forestry : Multi-scale conservation in a changing production forest matrix
- 2020
-
In: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 49:5, s. 1050-1064
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Journal article (peer-reviewed)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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| 11. |
- Fredriksson, Emelie, et al.
(author)
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Wildfire and prescribed burning impact moose forage availability and browsing levels in the northern boreal forest
- 2023
-
In: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 38, s. 58-69
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Journal article (peer-reviewed)abstract
- Fire regimes and herbivore densities have in parts of the boreal been heavily impacted by human activities with consequences for vegetation, forage supply and ungulate use. In this study, we evaluate the effects of natural wildfires and prescribed burning on moose forage availability, use, and browsing in northern Sweden. We studied three wildfire locations, adjacent controls, and five prescribed burns 12 years after fire. To compare forage availability and browsing levels we combined related variables with Principal Component Analyses and used the first axis in a regression analysis. The wildfire locations had a different composition of forage compared with the controls with less forage in the field layer and more woody browse and deciduous saplings. Forage availability was best explained by the occurrence of fire and differed between wildfire and the unburned control areas. Browsing levels were higher in wildfire locations compared with unburned controls. Prescribed burns varied substantially and could resemble both unburnt control and wildfire in terms of forage availability and browsing. We conclude that prescribed burning as a restoration action potentially can improve forage availability, particularly of deciduous species, if they mimic the impact of wildfires in terms of larger area burned and high fire severity.
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| 12. |
- Fredriksson, Emelie, et al.
(author)
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Wildfire yields a distinct turnover of the beetle community in a semi-natural pine forest in northern Sweden
- 2020
-
In: Ecological processes. - : Springer Science and Business Media LLC. - 2192-1709. ; 9
-
Journal article (peer-reviewed)abstract
- Background Fires have been an important natural disturbance and pervasive evolutionary force in the boreal biome. Yet, fire suppression has made forest fires rare in the managed landscapes in Fennoscandia, causing significant habitat loss for saproxylic species such as polypores and insects. To better understand how the beetle community changes (species turnover) after a wildfire in a landscape with intense fire suppression, we monitored beetles with flight intercept traps the first 3 years as well as 12 years after a large wildfire in a national park in northern Sweden (a control/unburnt area was set up for the last year of sampling). Results Species composition changed significantly among all studied years with a continuous turnover of species following the wildfire. The indicator species analysis showed that year 1 post-fire was mostly associated with cambium consumers and also the pyrophilous speciesBatrisodes hubenthali. Year 2 was the most abundant and species-rich year, withTomicus piniperdaas the most important indicator species. The indicator species year 3 were mostly secondary successional species, fungivores, and predators and were characterized by lower species diversity. Year 12 had higher diversity compared with year 3 but lower species richness and abundance. A control area was established during year 12 post-fire, and our analyses showed that the control area and burned area differed in species composition suggesting that the beetle community needs longer than 12 years to recover even after a low-intensive ground fire. Conclusion The wildfire area hosted several red-listed and fire-dependent species suggesting that after a century of landscape-level fire suppression in a semi-natural area, the reintroduction of fire benefits rare and pyrophilous species and still impacts species composition after 12 years. This study implies that fire has long-lasting effects on high latitudes and that prescribed burning has the potential to benefit biodiversity over decades in these landscapes while also highlighting the value of considering the whole species community and not only monitoring abundance and richness to assess biodiversity after management actions.
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| 13. |
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| 14. |
- Gibb, Heloise, et al.
(author)
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Foraging loads of red wood ants: Formica aquilonia (Hymenoptera: Formicidae) in relation to tree characteristics and stand age
- 2016
-
In: PeerJ. - : PeerJ. - 2167-8359. ; 4
-
Journal article (peer-reviewed)abstract
- Back ground. Foraging efficiency is critical in determining the success of organisms and may be affected by a range of factors, including resource distance and quality. For social insects such as ants, outcomes must be considered at the level of both the individual and the colony. It is important to understand whether anthropogenic disturbances, such as forestry, affect foraging loads, independent of effects on the quality and distribution of resources. We asked if ants harvest greater loads from more distant and higher quality resources, how individual efforts scale to the colony level, and whether worker loads are affected by stand age.Methods. First, we performed a fine-scale study examining the effect of distance and resource quality (tree diameter and species) on harvesting of honeydew by red wood ants, Formica aquilonia, in terms of crop load per worker ant and numbers of workers walking up and down each tree (ant activity) (study 1). Second, we modelled what the combination of load and worker number responses meant for colony-level foraging loads. Third, at a larger scale, we asked whether the relationship between worker load and resource quality and distance depended on stand age (study 2).Results. Study 1 revealed that seventy percent of ants descending trees carried honeydew, and the percentage of workers that were honeydew harvesters was not related to tree species or diameter, but increased weakly with distance. Distance positively affected load mass in both studies 1 and 2, while diameter had weak negative effects on load. Relationships between load and distance and diameter did not differ among stands of different ages. Our model showed that colony-level loads declined much more rapidly with distance for small diameter than large diameter trees.Discussion. We suggest that a negative relationship between diameter and honeydew load detected in study 1 might be a result of crowding on large diameter trees close to nests, while the increase in honeydew load with distance may result from resource depletion close to nests. At the colony level, our model suggests that very little honeydew was harvested from more distant trees if they were small, but that more distant larger trees continued to contribute substantially to colony harvest. Although forestry alters the activity and foraging success of red wood ants, study 2 showed that it does not alter the fundamental rules determining the allocation of foraging effort.
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| 15. |
- Gibb, Heloise, et al.
(author)
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Forest succession and harvesting of hemipteran honeydew by boreal ants
- 2010
-
In: Annales Zoologici Fennici. - : Finnish Zoological and Botanical Publishing Board. - 0003-455X .- 1797-2450. ; 47, s. 99-110
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Journal article (peer-reviewed)abstract
- Ants are important harvesters of plant-derived sugars, but little is known about how anthropogenic disturbances influence this behaviour. We investigated factors related to honeydew harvesting by red wood ants, Formica aquilonia, in managed boreal forests. Ant activity was lowest in middle-age stands (30-40 years old), which had the fewest and smallest ant mounds. It was best predicted by a model containing an interaction among tree species, basal diameter and stand age. Individual workers collected similar masses of honeydew from the different aged stands, which suggests that colonies optimise foraging efforts by adjusting the number of active foragers to match resource availability. The rate of honeydew harvesting from recently clear-cut stands during the survey was similar to that in old stands, although significantly faster than in middle-aged stands. This may be a result of high aphid loads on clear-cuts and recent changes in forest management that improve the temporal continuity of forests for red wood ants. Anthropogenic alteration of habitats thus significantly alters energy use by ants, mainly as a result of changes in the abundance and size of ant colonies. This change is likely to have further consequences for ant-driven ecosystem functions.
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| 16. |
- Gibb, Heloise, et al.
(author)
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Testing top-down and bottom-up effects on arid zone beetle assemblages following mammal reintroduction
- 2018
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In: Austral Ecology. - : Wiley. - 1442-9985 .- 1442-9993. ; 43, s. 288-300
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Journal article (peer-reviewed)abstract
- Species extinctions and declines are occurring globally and commonly have cascading effects on ecosystems. In Australia, mammal extinctions have been extensive, particularly in arid areas, where precipitation drives ecosystems. Many ecologically extinct mammals feed on soil-dwelling insects. However, how this top-down pressure affected their prey and how this contrasts with the bottom-up impacts of fluctuating precipitation remains unclear. We constructed a long-term exclusion experiment in a multi-species mammal reintroduction zone in semi-arid Australia to test how top-down (reintroduced mammals) and bottom-up (precipitation) factors affect root-feeding chafer beetles (Coleoptera: Melolonthinae). We used emergence traps in ten replicate 20 x 20 m plots of control, exclusion and procedural control treatments to trap chafers biannually from 2009 to 2015. Annual precipitation during this period varied from 173 to 481 mm. Mammal exclusion did not affect chafers, indicating that top-down regulation was not important. Instead, chafer abundance, species density and biomass increased with precipitation. Chafer body size and assemblage composition were best predicted by sampling year, suggesting that random drift determined species abundances. Increased resource availability therefore favoured all species similarly. We thus found no evidence that mammal predation alters chafer populations and conclude that they may be driven primarily by bottom-up processes. Further research should determine if the cascading effects of species loss are less important for herbivores generally than for higher level trophic groups and the role of ecosystem stability in mediating these patterns.
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| 17. |
- Hekkala, Anne-Maarit, et al.
(author)
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Ecological restoration for biodiversity conservation triggers response of bark beetle pests and their natural predators
- 2020
-
In: Forestry: An International Journal of Forest Research. - : Oxford University Press (OUP). - 1464-3626 .- 0015-752X. ; 94, s. 115-126
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Journal article (peer-reviewed)abstract
- 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.
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| 18. |
- Hjältén, Joakim, et al.
(author)
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Biodiversity benefits for saproxylic beetles with uneven-aged silviculture
- 2017
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 402, s. 37-50
-
Journal article (peer-reviewed)abstract
- Large scale use of even-aged silviculture (clear-cutting) commencing in the mid-20th century has had negative impacts on forest biodiversity. As a consequence, uneven-aged silviculture is currently being considered to help meet the ecological and social criteria required for sustainable forest management. Uneven-aged silviculture (e.g. selective felling) involves selective removal of some older trees in a stand which may to some extent mimics natural small scale stand dynamics and thus potentially benefit species associated with old forests. Here we test whether selective felling benefits beetle biodiversity by producing beetle assemblages that better resemble those of old growth stands than those found in uncut production stands. We conducted a field study in northern Sweden, comparing beetles assemblages collected with window traps in three spruce dominated stand types: (1) Stands recently (on average 7 years prior to the study) subjected to selective felling (Selective felling), (2) mature uneven-aged stands without recent history of management, resembling selective felling stands prior to management (Uncut), and (3) old-growth stands with high conservation values (Old growth). As predicted, we found that assemblage composition was similar in selective felling and old growth stands, and that assemblages of cambivores and obligate saproxylics (marginally significant) differed between these two stand types and uncut stands. The differences were largely explained by a higher abundance of saproxylic species presumably associated with old growth conditions and large volumes of deadwood. Thus, although overall assemblage composition did not differ between stand types, part of the beetle community seemingly benefited from selective felling. We therefore recommend that selective felling is considered as an alternative to clear-felling to maintain biodiversity values. (C) 2017 Elsevier B.V. All rights reserved.
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| 19. |
- Hjältén, Joakim, et al.
(author)
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Forest restoration by burning and gap cutting of voluntary set-asides yield distinct immediate effects on saproxylic beetles
- 2017
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In: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 26:7, s. 1623-1640
-
Journal article (peer-reviewed)abstract
- Today, the importance of restoring natural forest disturbance regimes and habitat structures for biodiversity is widely recognized. We evaluated the immediate effects of two restoration methods on wood-inhabiting (saproxylic) beetles in boreal forest voluntary set-asides. We used a before-after control-impact experimental set-up in 15 set-asides; each assigned to one of three treatments: (1) restoration burning, (2) gap cutting and (3) no-treatment reference stands. Before treatment, abundance, species richness and assemblage composition of trapped beetles did not differ significantly among treatments. Burning resulted in a significant change in assemblage composition and increased species richness and abundance compared to reference stands. As predicted, saproxylic species known to be fire favoured increased dramatically after burning. The immediate response shows that, initially, fire favoured species are attracted from the surrounding landscape and not produced on site. Gap cutting increased the abundance of cambium consumers but had no significant effect on total species richness or assemblage composition of saproxylic beetles. The stronger effect of burning compared to gap cutting on saproxylic assemblages is probably due to the very specific conditions created by fires that attracts many disturbance-dependent species, but that at the same time disfavour some disturbance-sensitive species. By contrast, gap cutting maintained assemblage composition, increased abundances and is likely to increase species richness in the years to follow, due to elevated level of dead wood. The restoration methods applied in this study may prove particularly useful, partly because of positive effect on saproxylic beetles, but also due to the cost-efficiency of the measures; the voluntary set-asides were already established and the restoration costs fully covered by revenue from the extracted timber.
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| 20. |
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| 21. |
- Hjältén, Joakim, et al.
(author)
-
Saproxylic Insects and Fire
- 2018
-
In: Saproxylic Insects : Diversity, Ecology and Conservation. - Cham : Springer International Publishing. - 9783319759364 ; :1, s. 669-691
-
Book chapter (peer-reviewed)
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| 22. |
- Hof, Anouschka, et al.
(author)
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Simulating Long-Term Effects of Bioenergy Extraction on Dead Wood Availability at a Landscape Scale in Sweden
- 2018
-
In: Forests. - : MDPI AG. - 1999-4907. ; 9
-
Journal article (peer-reviewed)abstract
- Wood bioenergy may decrease the reliance on fossil carbon and mitigate anticipated increases in temperature. However, increased use of wood bioenergy may have large impacts on forest biodiversity primarily through the loss of dead wood habitats. We evaluated both the large-scale and long-term effects of different bioenergy extraction scenarios on the availability of dead wood and the suitability of the resulting habitat for saproxylic species, using a spatially explicit forest landscape simulation framework applied in the Swedish boreal forest. We demonstrate that bioenergy extraction scenarios, differing in the level of removal of biomass, can have significant effects on dead wood volumes. Although all of the scenarios led to decreasing levels of dead wood, the scenario aimed at species conservation led to highest volumes of dead wood (about 10 m(3) ha(-1)) and highest connectivity of dead wood patches (mean proximity index of 78), whilst the scenario aimed at reaching zero fossil fuel targets led to the lowest levels (about 8 m(3) ha(-1)) and least connectivity (mean proximity index of 7). Our simulations stress that further exploitation of dead wood from sites where volumes are already below suggested habitat thresholds for saproxylic species will very likely have further negative effects on dead wood dependent species.
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| 23. |
- Hägglund, Ruaridh, et al.
(author)
-
Restoration measures emulating natural disturbances alter beetle assemblages in boreal forest
- 2020
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 462
-
Journal article (peer-reviewed)abstract
- Accelerating declines in biodiversity worldwide have accentuated the need for conservation actions. Unfortunately, the decline is unlikely to be reversed by traditional conservation alone, e.g., green tree retention at clear-felling and setting aside protected areas for free development. Instead the practice of ecological restoration has come to play an ever increasing role. Using a before-after control-impact experiment in boreal forest voluntary set-asides, we evaluated the usefulness of two methods of ecological restoration aimed at promoting biodiversity by emulating natural disturbances through restoration burning and artificial gap creation involving dead wood creation. In burned stands (n = 6) we removed up to 35% of the standing volume prior to burning, and in gap cut stands (n = 10) we removed the cut trees from every second gap; harvested trees covered costs for restoration. We used saproxylic and non-saproxylic beetles as a proxy for biodiversity to evaluate the two restoration methods. We compared species compositions of beetles collected with window traps one year before and one year after treatment. In addition, we compared catches in the treatments with those in untreated reference stands. Before treatment, we found no differences between the three groups of stands in terms of overall abundance, species richness or species composition. After treatment, the overall abundance of beetles was higher in the burned sites compared to the reference stands. Overall species richness was higher in burned stands compared to references and gap-cut stands. Gap-cut stands had higher species richness of cambivores and fire favoured species than reference stands. Species composition differed significantly between all three groups of stands. Among the 96 species that significantly contributed to the differences in species composition, 58 were more common in burned stands and 34 more common in gap-cut stands than in the other two stand groups. Nineteen of the 96 species are considered to be favored by forest fires, and 17 of these fire-favored species were more abundant in burned stands than gap-cut stands and/or references. Based on our results that burning and gap-cutting changed the beetle communities in partly different directions, we propose the use of both methods as complements to traditional conservation efforts in future attempts to improve conditions for biodiversity in managed boreal forest landscapes.
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| 24. |
- Joelsson, Klara, et al.
(author)
-
Uneven-aged silviculture can reduce negative effects of forest management on beetles
- 2017
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 391, s. 436-445
-
Journal article (peer-reviewed)abstract
- Decline in biodiversity have increased the interest in alternative forest management approaches. Uneven-aged silviculture has been proposed as a mean to maintain continuity of forest canopy cover, mimic small-scale disturbances and provide a stratified forest structure similar to that of old-growth forests and therefore better maintain species associated with unmanaged forest. We used a large-scale chronosequence study spanning 50 years to study beetle diversity in uneven-aged silviculture compared with both short-term impacts and the longer-term legacy of even-aged silviculture. We compared: (1) even-aged recently clear-felled stand, (2) even-aged recently thinned stand, (3) uneven-aged stands subjected to selective felling with (4) uneven-aged reference stands to evaluate whether abundance, species richness and composition of beetles (Coleoptera) were affected differently by even-aged than by uneven-aged management. We collected 15,147 beetles from 461 species using flight interception traps in 30 stands. Beetle composition was maintained in uneven-aged managed stands; composition did not differ from unmanaged reference stands, the exception being cambium consumers. Both even-aged silviculture treatments (clear-felling and thinning) had different beetle composition compared to the reference stands, indicating that assemblages had yet to recover even 50 years into the rotation. However, beetle composition did not differ between uneven-aged managed and thinned stands. The result supports our prediction that uneven-aged silviculture better maintains beetles assemblages associated with semi-natural mature forest than even-aged silviculture. The greater temporal continuity in selectively felled stands could benefit species dependent of mature or old growth forest since some of the needed habitat qualities are continuously available. Uneven-aged silviculture could therefore serve as an important tool for landscape planning to benefit biodiversity and thus help fulfil environmental commitments. However, uneven-aged silviculture may still alter the forest and should therefore be viewed as an alternative to even-aged silviculture, rather than to set-asides.
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| 25. |
- Larsson Ekström, Albin, et al.
(author)
-
A decadal study reveals that restoration guided by an umbrella species does not reach target levels
- 2024
-
In: Journal of Applied Ecology. - 0021-8901 .- 1365-2664. ; 61, s. 513-525
-
Journal article (peer-reviewed)abstract
- Maintaining structural and functional elements of ecosystems are essential in order to preserve biodiversity and ecosystem function. As a means of guiding conservation work, the umbrella species concept was developed. In Sweden, one putative umbrella species, the white-backed woodpecker, has guided conservation and restoration of deciduous forests for two decades. Here, we evaluate the decadal effects of restoration aimed at the white-backed woodpecker on biodiversity of saproxylic beetles. We compare stands that were restored 12 to 21 years ago to non-restored stands and historical white-backed woodpecker habitats acting as restoration target stands. Restored stands contained higher deciduous deadwood volumes than non-restored stands but lower volumes than restoration target stands. The deadwood in restored stands was concentrated in later decay stages, whereas target stand deadwood was more evenly distributed across decay stages. Restored stands had similar species richness and abundance of most groups of saproxylic beetles compared with non-restored stands while not reaching the levels of restoration target stands. Species assemblages differed among all stand types with restored stands supporting late decay stage and generalist species while target stands supported more deciduous associated and threatened species. Synthesis and applications: We conclude that after one to two decades, restoration improve stand structure and benefit beetle diversity but that target levels are not yet reached. Thus, only partial restoration is achieved. Our results stress that for restoration to be successful both continuous and repeated restoration efforts are needed and that it is important to identify target levels of important habitat characteristics when assessing restoration outcome.We conclude that after one to two decades, restoration improve stand structure and benefit beetle diversity but that target levels are not yet reached. Thus, only partial restoration is achieved. Our results stress that for restoration to be successful both continuous and repeated restoration efforts are needed and that it is important to identify target levels of important habitat characteristics when assessing restoration outcome. image
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| 26. |
- Larsson Ekström, Albin, et al.
(author)
-
Reinventory of permanent plots show that kelo lichens face an extinction debt
- 2023
-
In: Biological Conservation. - 0006-3207 .- 1873-2917. ; 288
-
Journal article (peer-reviewed)abstract
- Intensive forestry has led to landscape level deficits of important substrates such as deadwood and its associated biodiversity. Several taxa face extinction debts due to continuous declines and lack of regeneration of important habitats. Deadwood-dependent lichens are of great conservation concern due to a general lack of deadwood and due to their slow establishment, especially of rare species. In a field restoration experiment in central Sweden, we studied deadwood-dependent lichens for eight years, their association to different types of deadwood and their response to environmental change caused by variable retention forestry, deadwood enrichment and prescribed burning. Prescribed burning and site preparation caused depauperate lichen species assemblages throughout the study period but retention felling did not majorly affect lichen species assemblages. We found that lichen species were nested along deadwood qualities and deadwood created in the experiment only hosted a subset of lichen species found on kelo wood. Despite large reductions of kelo wood with lichen occurrences over the study period, overall species richness did not decrease. The fact that a large part of the lichen community occur only on kelo wood and that kelo wood is not regenerated implies that lichens associated with kelo wood face an extinction debt. In order to avoid local extinctions of deadwood-dependent lichens, site preparation and prescribed burning should be avoided in areas rich in high quality deadwood. There is urgent need to start creating new kelo wood through reoccurring fires in order to halt the impending extinction debt.
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| 27. |
- Lindberg, Eva, et al.
(author)
-
Can Airborne Laser Scanning (ALS) and Forest Estimates Derived from Satellite Images Be Used to Predict Abundance and Species Richness of Birds and Beetles in Boreal Forest?
- 2015
-
In: Remote Sensing. - : MDPI AG. - 2072-4292. ; 7, s. 4233-4252
-
Journal article (peer-reviewed)abstract
- In managed landscapes, conservation planning requires effective methods to identify high-biodiversity areas. The objective of this study was to evaluate the potential of airborne laser scanning (ALS) and forest estimates derived from satellite images extracted at two spatial scales for predicting the stand-scale abundance and species richness of birds and beetles in a managed boreal forest landscape. Multiple regression models based on forest data from a 50-m radius (i.e., corresponding to a homogenous forest stand) had better explanatory power than those based on a 200-m radius (i.e., including also parts of adjacent stands). Bird abundance and species richness were best explained by the ALS variables "maximum vegetation height" and "vegetation cover between 0.5 and 3 m" (both positive). Flying beetle abundance and species richness, as well as epigaeic (i.e., ground-living) beetle richness were best explained by a model including the ALS variable "maximum vegetation height" (positive) and the satellite-derived variable "proportion of pine" (negative). Epigaeic beetle abundance was best explained by "maximum vegetation height" at 50 m (positive) and "stem volume" at 200 m (positive). Our results show that forest estimates derived from satellite images and ALS data provide complementary information for explaining forest biodiversity patterns. We conclude that these types of remote sensing data may provide an efficient tool for conservation planning in managed boreal landscapes.
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| 28. |
- Lindberg, Eva, et al.
(author)
-
Can airborne laser scanning or satellite images, or a combination of the two, be used to predict the abundance and species richness of birds and beetles at a patch scale?
- 2014
-
Conference paper (peer-reviewed)abstract
- Management of forests for biodiversity conservation requires knowledge on the habitat needs of forest-dwelling species. Important habitat factors include local stand conditions such as forest structure and tree species composition as well as the amount and distribution of suitable local habitats in a surrounding landscape. Information at both these scales can be efficiently derived from remotely sensed data.Focusing on the European boreal forest, this paper presents an analysis of the relation between the local-scale abundance and species richness of forest-dwelling birds and beetles on the one hand, and information derived from airborne laser scanning (ALS) data and satellite images on the other. The aim is to answer the following questions: 1. Can ALS-data or satellite image data or a combination of the two be used to identify important habitats for forest dwelling beetles and birds in boreal forest? 2. Which type of remote sensing data can best explain biodiversity patterns for beetle and birds species in boreal forest? 3. How accurate can different remote sensing methods predict biodiversity patterns at different spatial scales?
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| 29. |
- Lindberg, Eva, et al.
(author)
-
Does detailed vegetation structure derived from airborne laser scanning (ALS) contribute to prediction of abundance and species richness of birds and beetles in boreal forest?
- 2015
-
Conference paper (other academic/artistic)abstract
- In managed landscapes, conservation planning requires effective methods to identify high-biodiversity areas. Satellite images and airborne laser scanning (ALS) can provide information about vegetation over large areas. This study evaluates the potential of detailed vegetation structure derived from ALS data for predicting the stand-scale abundance and species richness of birds and beetles in a managed boreal forest landscape. Earlier results have shown that bird abundance and species richness were best explained by the ALS variables "maximum vegetation height" and "vegetation cover between 0.5 and 3 m" (both positive), while the abundance and species richness of flying beetles as well as epigaeic (i.e., ground-living) beetles were best explained by a model including the ALS variable "maximum vegetation height" (positive) and the satellite-derived variable "proportion of pine" (negative). Now we include new explanatory variables describing the size of the tree crowns and the patchiness of the canopy derived from ALS data. The results demonstrate the level of detail in vegetation structure that can be obtained from ALS data and the importance of this information compared to other variables derived from remote sensing on a coarser scale.
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| 30. |
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| 31. |
- Löfroth, Therese, et al.
(author)
-
Deadwood Biodiversity
- 2023
-
In: Boreal Forests in the Face of Climate Change : Sustainable Management. - Cham : Springer International Publishing. - 9783031159879 ; :74, s. 167-189
-
Book chapter (peer-reviewed)abstract
- Deadwood is a key component for biodiversity and ecosystem services in boreal forests; however, the abundance of this critical element is declining worldwide. In natural forests, deadwood is produced by tree death due to physical disturbances, senescence, or pathogens. Timber harvesting, fire suppression, and salvage logging reduce deadwood abundance and diversity, and climate change is expected to bring further modifications. Although the effects of these changes are not yet fully understood, restoring a continuous supply of deadwood in boreal forest ecosystems is vital to reverse the negative trends in species richness and distribution. Increasing the availability of deadwood offers a path to building resilient forest ecosystems for the future.
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| 32. |
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| 33. |
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| 34. |
- Löfroth, Therese, et al.
(author)
-
Flow-on effects of an introduced tree species: Lodgepole pine plantation affects function and performance of boreal ants
- 2022
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 512
-
Journal article (peer-reviewed)abstract
- Increased demand on forests to produce renewable biomass have accelerated the use of non-native tree species in forestry worldwide, often with negative effects on native biodiversity. In Sweden, the North American lodgepole pine (Pinus contorta Douglas ex. Loudon var. latifolia) was introduced already in the 1970's. Even though the species now covers large areas, effects on native flora and fauna have not been thoroughly evaluated. In this study, we used a large-scale field experiment with 30 paired P. contorta and P. sylvestris stands in central and northern Sweden to study the effects of P. contorta plantation on the abundance and activity of red wood ants of the Formica rufa-group, density and species richness of other ant species, as well as possible effects on the abundance of the specialized ant predator Pella humeralis. We collected epigaeic insects with pit fall traps, surveyed wood ant mound density and volume, and monitored ant activity on trees in all stands. Our analyses revealed a trend with higher mound density in P. sylvestris compared with P. contorta stands, although wood ant worker catch did not differ between the pine species. However, red wood ant activity was significantly higher in P. sylvestris stands, suggesting that P. contorta is not a preferred tree species for the tending of aphids for honeydew. Total ant species richness as well as the catch of Camponotus herculeanus and Myrmica ruginodis were higher in P. sylvestris stands, suggesting that they constitute a more favorable habitat for ants. Ant species richness was negatively influenced by wood ants in P. sylvestris stands only. A similar pattern was shown for C. herculeanus. Myrmica ruginodis was more abundant in P. sylvestris stands only if no thinning had been applied. Wood ant catch was positively correlated with catch of the specialized predatory rove beetle Pella humeralis showing that there is a strong interaction between the predatory beetle and wood ants.Our results suggest that P. contorta plantations impact both red wood ants and associated species and although competition from wood ants is more pronounced in P. sylvestris stands they still constitute a more favorable habitat for most ant species. Thus, large scale plantation of the non-native but closely related P. contorta may negatively impact epigaeic assemblages, a pattern that is not compensated by released competition by dominant red wood ants.
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| 35. |
- Löfroth, Therese, et al.
(author)
-
Forestry Alters Foraging Efficiency and Crop Contents of Aphid-Tending Red Wood Ants, Formica aquilonia
- 2012
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7
-
Journal article (peer-reviewed)abstract
- Forest management alters species behaviours, distributions and interactions. To evaluate forestry effects on ant foraging performance, we compared the quality and quantity of honeydew harvested by ants among clear-cuts, middle-aged and mature spruce-dominated stands in boreal forests in Sweden. Honeydew quality was examined using honeydew collected by squeezing the gasters of laden Formica aquilonia workers. We used fifteen laden individuals at each study site (four replicates of each stand age) and analysed honeydew chemical composition with gas chromatography-mass spectroscopy. To compare the quantity of honeydew collected by individual ants, we collected and weighed five ants moving up and five ants moving down each of ten trees at the twelve sites (totally 1200 ants). The concentration of trehalose in honeydew was lower in clear-cuts compared with middle aged and mature stands, and similar trends were shown for sucrose, raffinose and melezitose, indicating poorer honeydew quality on clear cuts. Concentrations of the amino acid serine were higher on clear-cuts. The same trend occurred for glutamine, suggesting that increased N-uptake by the trees after clear cutting is reflected in the honeydew of aphids. Ants in mature stands had larger heads and carried proportionally more honeydew and may therefore be more efficient foragers. Human alternation of habitats through clear-cutting thus affects food quality and worker condition in F. aquilonia. This is the first study to show that honeydew quality is affected by anthropogenic disturbances, likely contributing to the reduction in size and abundance of F. aquilonia workers and mounds after clear cutting.
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| 36. |
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| 37. |
- Löfroth, Therese, et al.
(author)
-
Interspecific competition and coexistence between wood ants
- 2016
-
In: Wood Ant Ecology and Conservation. - 9781107261402 ; , s. 123-144
-
Book chapter (peer-reviewed)abstract
- Competition among or within species has long been considered one of the most fundamental processes shaping ecological communities, affecting distributions and the evolution of species. While its importance and detectability are strongly debated (Schaffer et al. 1979; Schoener 1982; Connell 1983; Schoener 1983), its role in structuring ant assemblages has often been uncritically accepted and competition is even referred to as ‘the hallmark of ant ecology' (Hölldobler and Wilson 1991). Competition between species, i.e. interspecific competition, has been a major theme in the study of wood ants and their role in species assemblages. This chapter considers interspecific competition as it relates to wood ants, including the behavioural interactions with other ant species and mechanisms of coexistence. Theories regarding the competitive structuring of ant assemblages by wood ants through dominance hierarchies (see below) and the observational and experimental evidence for this are discussed. Factors that regulate competition from wood ants, competitive interactions with other taxa and avenues for advancing our understanding of this topic are also considered.
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| 38. |
- Löfroth, Therese, et al.
(author)
-
Land-sparing benefits biodiversity while land-sharing benefits ecosystem services : Stakeholders’ perspectives on biodiversity conservation strategies in boreal forests
- 2024
-
In: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 53:1, s. 20-33
-
Journal article (peer-reviewed)abstract
- Biodiversity conservation and economic profit from forests can be combined by various land-sparing and land-sharing approaches. Using a semi-structured survey, we evaluated support for scenarios representing contrasting conservation strategies in a managed boreal forest landscape. Land-sparing approaches were supported by the conservation organisation, regional administrations and the forest company, mainly motivated by the benefit for biodiversity based on ecological theory. Land-sharing approaches were supported by one recreational organisation, some municipalities and the forest owners’ association, mainly motivated by the delivery of ecosystem services. Stakeholder groups using certain ecosystem services had motivations that we related to an anthropocentric mindset, while others focused more on species conservation, which can be related both to an anthropocentric or an ecocentric mindsets. Forest conservation planning should consider stakeholders’ preferences to handle land-use conflicts. Since reaching consensus among multiple stakeholders seems unfeasible, a combination of land-sparing and land-sharing approaches is probably the best compromise.
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| 39. |
- Löfroth, Therese, et al.
(author)
-
Responses of woody vegetation to exclusion of large herbivores in semi-arid savannas
- 2012
-
In: Austral Ecology. - : Wiley. - 1442-9985. ; 37, s. 56-66
-
Journal article (peer-reviewed)abstract
- The Nkuhlu large-scale long-term exclusion experiment in Kruger National Park was designed to study the long-term effects of large herbivores on vegetation. One treatment excludes elephants, another excludes all herbivores larger than hares and another one comprises an open, control area. Vegetation monitoring was implemented in 2002 when a baseline survey was conducted prior to exclusion. Monitoring was repeated 5 years after exclusion. Data from the surveys were analysed to establish how structure and composition of woody vegetation had changed 5 years after herbivore exclusion. The analysis showed that neither plant assemblage nor mean vegetation height had changed significantly since exclusion. However, both species richness and density of woody plants increased 5 years after exclusion of all large herbivores, but not after the exclusion of elephants alone. One already common species, Dichrostachys cinerea, became more common after excluding all large herbivores compared with either no exclusion or elephant exclusion, possibly leading to competitive suppression of other species. Species other than D. cinerea tended to either increase or decrease in density, but the changes were insufficient to induce significant shifts in the overall assemblage of woody plants. The results indicate that after 5 years of exclusion, the combined assemblage of large herbivores, and not elephants alone, could induce changes in species richness and abundances of woody plants, but the effect was so far insufficient to induce measureable shifts in the assemblages of woody plants. It is possible that assemblages will change with time and increasing elephant numbers may amplify future changes.
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| 40. |
- Löfroth, Therese, et al.
(author)
-
Soil humidity, potential solar radiation and altitude affect boreal beetle assemblages in dead wood
- 2017
-
In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 209, s. 107-118
-
Journal article (peer-reviewed)abstract
- Topographic heterogeneity causes gradients in altitude, potential solar radiation and soil humidity on a range of scales from micro- to macro-habitat These gradients are important determinants for the distribution of many organisms but have been largely neglected in studies of species associated with dead wood, a group of great conservation concern. In this study, we evaluated the effects of topography-related gradients (altitude, potential solar radiation and soil humidity) and habitat characteristics (bark cover, ground contact and dead wood volume) on saproxylic (wood-inhabiting) beetle assemblages. We sampled boreal saproxylic beetles hatching from 750 experimentally exposed spruce and birch logs in a regional scale field experiment including 10 landscapes and spanning gradients of altitude (range 85-510 m asl), potential solar radiation (based on slope and slope aspect and highest in equator-facing slopes, PADIR, range 0.24-0.71) and soil humidity (humidity index, range 2.3-3.1). The logs were placed in north Swedish forests and clear-cuts and beetles were sampled with emergence traps the 4th summer after the logs were introduced. Saproxylic assemblage composition varied considerably in response to altitude, potential solar radiation and soil humidity. The response was evident in both forests and clear-cuts and for both birch and spruce logs. Species density and abundance responses differed among trophic groups. For birch logs, fungivore species density increased significantly with increased potential solar radiation. For spruce logs, altitude affected total species density and density of cambium consumers positively and abundance of fungivores negatively, suggesting a delay in succession due to slower decomposition at higher altitudes. In addition to the topography-related gradients, ground contact and bark cover of logs as well as the availability of dead wood in the vicinity influenced the beetle assemblages. Our results clearly show that topography-related gradients affect assemblage composition of saproxylic beetles. These factors should be considered in the management of saproxylic biodiversity. To ensure the safeguarding of intact saproxylic assemblages it is important that the full range of dead wood habitats is conserved. Topographic heterogeneity may provide opportunities for landscape scale survival in response to rapid climate change but there is also a risk that some niches will disappear. Some of the negative effects of climate change could be mitigated by allocating set asides and restoration efforts in areas where gradient in altitude, solar radiation and soil humidity are particularly well developed over short distances. (C) 2017 Elsevier Ltd. All rights reserved.
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| 41. |
- Rodriguez, Antonio, et al.
(author)
-
Boreal forest fertilization leads to functional homogenization of ground beetle assemblages
- 2021
-
In: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 58, s. 1145-1154
-
Journal article (peer-reviewed)abstract
- Intensive fertilization of young spruce forest plantations (i.e. 'nutrient optimization') has the potential to meet increasing demands for carbon sequestration and biomass production from boreal forests. However, its effects on biodiversity, other than the homogenization of ground-layer plant communities, are widely unknown.We sampled ground beetles (Coleoptera: Carabidae) in young spruce forest plantations of southern Sweden, within a large-scale, replicated ecological experiment initiated in 2012, where half of the forest stands were fertilized every second year. We assessed multi-scale effects of forest fertilization on ground beetle diversity and community assembly, 4 years after commencement of the experiment.We found that nutrient optimization had negative effects on ground beetle diversity at multiple spatial scales, despite having negligible effects on species richness. At the local scale, ground beetle species had lower variation in body size at fertilized sites, resulting in within-site functional homogenization. At the landscape scale, fertilized sites, with higher basal area and lower bilberry cover, filtered carabid traits composition to larger body sizes, generalist predators and summer breeding species.Synthesis and applications. Fertilization of young spruce plantations is a strong filter for ground beetle assemblages, leading to functionally homogeneous communities in the short term, without changes in species richness. The large-scale functional impoverishment of carabid communities because of fertilization may have negative consequences on system resilience and on ecosystem service provision by this functionally diverse group. Large-scale establishment of nutrient optimization threatens ground beetle diversity in young conifer plantations, underlining the risks of introducing more intensive management schemes in already heavily managed forest landscapes.
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| 42. |
- Stenbacka, Fredrik, et al.
(author)
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Saproxylic parasitoid (Hymenoptera, Ichneumonoidea) communities in managed boreal forest landscapes
- 2010
-
In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 3, s. 114-123
-
Journal article (peer-reviewed)abstract
- 4. The general distribution pattern revealed no significant differences in species richness among stand types, but parasitoid assemblages were affected by forest successional stage. Idiobionts, dominated by Ontsira antica and Bracon obscurator, preferred clear-cuts over forested sites, while koinobionts, especially Cosmophorus regius, were more common in mature forests and reserves. We conclude that the stand types studied were complementary in assemblage composition, but that none held a complete assemblage of saproxylic parasitoids and we suggest that a range of successional stages be retained to help conserve the entire parasitoid community.
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| 43. |
- Tranberg, Olov, et al.
(author)
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Translocation of deadwood in ecological compensation: A novel way to compensate for habitat loss
- 2024
-
In: AMBIO: A Journal of the Human Environment. - 0044-7447 .- 1654-7209. ; 53, s. 482-496
-
Journal article (peer-reviewed)abstract
- Restoration of degraded habitat is frequently used in ecological compensation. However, ecological restoration suffers from innate problems of long delivery times of features shown to be good proxies for biodiversity, e.g., large dead trees. We tested a possible way to circumvent this problem; the translocation of hard-to-come deadwood substrates from an impact area to a compensation area. Following translocation, deadwood density in the compensation area was locally equivalent to the impact area, around 20 m3 ha-1, a threshold for supporting high biodiversity of rare and red-listed species. However, deadwood composition differed between the impact and compensation area, showing a need to include more deadwood types, e.g., late decomposition deadwood, in the translocation scheme. To guide future compensation efforts, the cost for translocation at different spatial scales was calculated. We conclude that translocation of deadwood could provide a cost-efficient new tool for ecological compensation/restoration but that the method needs refinement.
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| 44. |
- Tälle, Malin, et al.
(author)
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Land sharing complements land sparing in the conservation of disturbance-dependent species
- 2023
-
In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 52:3, s. 571-584
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Research review (peer-reviewed)abstract
- Alteration of natural disturbances in human-modified landscapes has resulted in many disturbance-dependent species becoming rare. Conservation of such species requires efforts to maintain or recreate disturbance regimes. We compared benefits of confining efforts to habitats in protected areas (a form of land sparing) versus integrating them with general management of production land (a form of land sharing), using two examples: fire in forests and grazing in semi-natural grasslands. We reviewed empirical studies from the temperate northern hemisphere assessing effects of disturbances in protected and non-protected areas, and compiled information from organisations governing and implementing disturbances in Sweden. We found advantages with protection of areas related to temporal continuity and quality of disturbances, but the spatial extent of disturbances is higher on production land. This suggests that an approach where land sparing is complemented with land sharing will be most effective for preservation of disturbance-dependent species in forests and semi-natural grasslands.
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