| 1. |
- Bergmark, Paulina, et al.
(author)
-
Trait-environment interactions of saproxylic beetles as a guide to biodiversity conservation strategies
- 2024
-
In: Journal of Environmental Management. - 0301-4797 .- 1095-8630. ; 360
-
Journal article (peer-reviewed)abstract
- Conservation of biodiversity requires in-depth knowledge of trait-environment interactions to understand the influence the environment has on species assemblages. Saproxylic beetles exhibit a wide range of traits and functions in the forest ecosystems. Understanding their responses to surrounding environment thus improves our capacity to identify habitats that should be restored or protected. We investigated potential interactions between ecological traits in saproxylic beetles (feeding guilds and habitat preferences) and environmental variables (deadwood, type and age of surrounding forest). We sampled beetles from 78 plots containing newly created high stumps of Scots pine and Silver birch in boreal forest landscapes in Sweden for three consecutive years. Using a model based approach, our aim was to explore potential interactions between ecological traits and the surrounding environment at close and distant scale (20 m and 500 m radius). We found that broadleaf-preferring beetle species are positively associated with the local broadleaf-originated deadwood and broadleaf-rich forests in the surrounding landscapes. Conifer-preferring species are positively associated with the local amount of coniferous deadwood and young and old forests in the surrounding landscape. Fungivorous and predatory beetles are positively associated with old forests in the surrounding landscapes. Our results indicate that both local amounts of deadwood and types of forests in the landscape are important in shaping saproxylic beetle communities. We particularly highlight the need to increase deadwood amounts of various qualities in the landscape, exempt older forests from production and to increase broadleaf-rich habitats in order to meet different beetle species' habitat requirements. Trait responses among saproxylic beetles provide insights into the significance of broadleaf forest and dead wood as essential attributes in boreal forest restoration, which helps conservation planning and management in forest landscapes.
|
|
| 2. |
- Hekkala, Anne-Maarit, et al.
(author)
-
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
-
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.
|
|
| 3. |
- Hekkala, Anne-Maarit, et al.
(author)
-
Habitat heterogeneity is a good predictor of boreal forest biodiversity
- 2023
-
In: Ecological Indicators. - : Elsevier BV. - 1470-160X .- 1872-7034. ; 148
-
Journal article (peer-reviewed)abstract
- Reliable assessment measures are crucial for tracking changes in biodiversity and for evaluating the state of biodiversity. Two of the main drivers of biodiversity are habitat heterogeneity and resource amount. These drivers are used as proxies of biodiversity but assessing both is costly, limiting their practical use. To test which of the drivers best predicts the number and abundance of sessile species of conservation concern (including macrofungi, lichens, bryophytes, and vascular plants), we assessed forest stand heterogeneity using a method developed in Sweden ('Habitat Heterogeneity Score HHS'), and quantified the resource amount and quality of ecologically important structural variables (deadwood volume, basal area of living trees, proportion of broadleaved trees, and the age of the oldest tree in the stand). We conducted the assessments in 77 boreal coniferdominated forest stands in two regions of Sweden. Despite some group-specific organism differences, HHS was the best predictor of both number and abundance of all species of conservation concern, regardless of the region. Further, HHS was the best predictor of red-listed species number and abundance in the southern region, while a model including the volume of deadwood and the age of the oldest tree performed best in the northern region. Deadwood (CWD) volume was the single best resource amount predictor of the number and abundance of species of conservation concern, emphasizing the critical role that dead trees have for biodiversity. In addition, we calculated threshold values for deadwood volume and HHS depicting the level above which the number of red-listed species is significantly higher, and found this value to be higher in the southern region (22.4 m(3) ha(-1) deadwood and a HSS value of 17) than in the north (20.0 m(3) ha(-1) and 16). These values can be used as guidance when identifying coniferous forests with high enough qualities to support red-listed species. To conclude, the method of assessing habitat heterogeneity presented in this study is a practical and reliable way to identify forests of high biological diversity, and can therefore be part of the toolbox for sustainable forestry in boreal forests.
|
|
| 4. |
- Hekkala, Anne-Maarit
(author)
-
Restoring volume, diversity and continuity of deadwood in boreal forests
- 2016
-
In: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 25, s. 1107-1132
-
Journal article (peer-reviewed)abstract
- Restoration of boreal forests by emulating natural disturbances is used to bring back typical components of natural forests that are reduced by silvicultural management. The volume, diversity and continuity of deadwood are the most important factors determining the diversity of deadwood-dependent species. In a large-scale experiment consisting of 43 experimental stands and 15 controls we assessed how alternative restoration methods enhancing deadwood availability (felling and felling + burning with two levels of felling: 20 and 40 % of initial volume of living trees, and a storm treatment) would affect short-and long-term deadwood volume and diversity using 7-year deadwood measurements and simulation modelling. In short-term, restoration by felling + burning increased both the volume and diversity of deadwood, whereas felling only increased merely the volume of deadwood. The simulations of tree growth, mortality and wood decomposition indicated that in comparison to controls, felled and storm-treated stands have greater deadwood volumes up to 40 years and felled + burned stands more than 60 years after restoration. Our results suggest that felling with 20 % of initial tree volume does not harm the future deadwood continuity, whereas intensive burning may imperil the deadwood continuity in a stand level. In conclusion, restoration clearly speeds up the development of the deadwood volumes needed to host large portions of biodiversity, and burning is the most effective restoration method in short- and long term. In practice, several restoration methods could be used concurrently in the landscape to obtain the best results.
|
|
| 5. |
- Hekkala, Anne-Maarit, et al.
(author)
-
The use of response measures in meta-analyses of land-use impacts on ecological communities: a review and the way forward
- 2018
-
In: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 27, s. 2989-3005
-
Research review (peer-reviewed)abstract
- Species richness and total abundance are two of the most commonly used response measures in empirical studies of the effects of anthropogenic land-use on biodiversity, in spite of the fact that they are insensitive to changes in a range of community attributes. We evaluated the extent to which meta-analyses about the effects of forest land-use on ecological communities make use of gross species richness, diversity and abundance measures (hereafter low-informative measures) as opposed to more refined response variables conveying a higher degree of conservation-relevant information, e.g., by accounting for compositional or functional changes in the communities (high-informative measures). Nearly one-half of the 221 included meta-analyses were based solely on low-informative measures. The prevalence of low-informative measures was higher for meta-analyses belonging to studies encompassing a broad taxonomic scope and it has increased since 2002. Few differences were detected in the use of response measures among taxonomic groups, although there were indications that some better-known groups tended to be more often studied with high-informative measures. To provide guidance for future work, we synthesized the high-informative measures of biodiversity used in the reviewed studies. For better-informed meta-analyses, we encourage the use of more refined approaches to quantify impacts on communities in addition to species richness and total abundance measures. This may involve, for example, the use of beta diversity and functional diversity measures, as well as separate analyses for different ecological groups or conservation status categories.
|
|
| 6. |
- 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)
|
|
| 7. |
- Hägglund, Ruaridh, et al.
(author)
-
Positive effects of ecological restoration on rare and threatened flat bugs (Heteroptera: Aradidae)
- 2015
-
In: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 19, s. 1089-1099
-
Journal article (peer-reviewed)abstract
- Intensive management of boreal forests has replaced natural disturbances, leading to losses of residual deadwood and saproxylic biodiversity. Declining population sizes have been well documented for insect groups such as bark and wood-boring beetles, whilst other groups such as flat bugs (Heteroptera: Aradidae) are less well-studied and little is known about their response to forest restoration. We conducted two restoration experiments addressing this lack of knowledge. We predicted the following responses to restoration: (1) artificial gap-creation and prescribed burning will attract more flat bugs than control stands, (2) increasing pre-burning fuel loads will have a positive influence on flat bug response to fire restoration. To test these predictions we conducted two field experiments; in Sweden we compared prescribed burning of standing forest with artificial gap-creation and in Finland we compared differing levels of fuel-load prior to burning. We found partial support for our first prediction, total numbers of flat bugs collected was higher in burned forest stands compared to controls in both countries. By contrast, gap-cutting only resulted in a marginal increase in the numbers and species of flat bugs collected. We found no support for our second hypothesis. The red-listed Aradus angularis and A. laeviusculus were primarily found in burned stands. Aradus betulae, A. betulinus and A. lugubris were more frequent in burned stands than gap-cuttings and untreated controls. Our study therefore suggests that ecological restoration, especially burning, is an efficient way of attracting flat bugs to suitable habitat, we therefore recommend ecological restoration to be incorporated in boreal forest management.
|
|
| 8. |
- Kärvemo, Simon, et al.
(author)
-
Multi-taxon conservation in northern forest hot-spots: the role of forest characteristics and spatial scales
- 2021
-
In: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 36, s. 989-1002
-
Journal article (peer-reviewed)abstract
- Context Biodiversity is highly affected by industrial forestry, which leads to the loss and fragmentation of natural habitats. To date, most conservation studies have evaluated associations among a single species group, forest type, or spatial scale. Objective The objective was to evaluate the richness of multiple species groups across various forest types and characteristics at multiple scales. Methods We used the occurrence data for 277 species of conservation interest from 455 stands of high conservation value, including four species groups and four forest types. Results Local, landscape, and regional forest characteristics influenced biodiversity in a non-uniform pattern among species groups and forest types. For example, an increased local spruce basal area in spruce forests was associated with higher vascular plant and bryophyte richness values, whereas macrofungi and lichen richness were positively correlated with deadwood availability, but negatively correlated with the spruce volume in the landscape. Furthermore, landscapes with twice as much mature forest as the average, had more than 50% higher richness values for vascular plants, macrofungi, and lichens. Conclusion Among sessile species groups in northern forests, a uniform conservation strategy across forest types and scales is suboptimal. A multi-faceted strategy that acknowledges differences among species groups and forest types with tailored measures to promote richness is likely to be more successful. Nevertheless, the single most common measure associated with high richness across the species groups and forest types was mature forest in the landscape, which suggests that increasing old forests in the landscape is a beneficial conservation strategy.
|
|
| 9. |
- Larsson Ekström, Albin, et al.
(author)
-
Can multifunctional forest landscapes sustain a high diversity of saproxylic beetles?
- 2021
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 490
-
Journal article (peer-reviewed)abstract
- Intensive forestry practices have led to fragmentation of habitats that have high conservation value and has reduced the availability of deadwood in forests. This has in turn, led to a decline in species associated with deadwood (e.g. saproxylic beetles). Conservation measures have been developed in order to halt the negative trend in forest biodiversity, both at local and landscape scales. Ecoparks are large forest landscapes, with at least 50% of the forestland being managed with enhanced conservation concern including legal and voluntary protection or restoration of forests. Ecoparks aim to combine production, nature conservation and recreation (e.g. berry picking, hiking, hunting, fishing) and thereby represent multifunctional forest landscapes. The purpose of this study was to evaluate whether ecoparks can sustain greater diversity of saproxylic beetles than conventionally managed production landscapes, and whether the local habitat amount and diversity can have an additional effect on species assemblages. Two ecoparks and two representative conventional production landscapes, which implement a rotation forestry with general nature consideration, were selected for the study. Beetles were collected during three years in sun-exposed plots, where local (20 m radius) forest structures were measured. We found that both ecoparks sustained greater abundance and richness of nationally red-listed beetles (IUCN classes NT, VU, EN) and contained different beetle assemblages in comparison with conventional landscapes. Local deadwood volume had a positive relationship with the richness and abundance of saproxylic and red-listed beetles in the southern study area (long history of land-use), but not in the north (short history of landuse), partially supporting habitat amount hypothesis (HAH) at the local scale. Instead, the responses of beetles to deadwood diversity showed inconclusive results, varying between years and study areas. Our results highlight the potential of multifunctional forests in conserving biodiversity of saproxylic beetle species, especially redlisted species, as well as the importance of local deadwood availability.
|
|
| 10. |
- Oresic, Matej, 1967-, et al.
(author)
-
Dysregulation of lipid and amino acid metabolism precedes islet autoimmunity in children who later progress to type 1 diabetes
- 2008
-
In: Journal of Experimental Medicine. - New York, USA : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 205:13, s. 2975-2984
-
Journal article (peer-reviewed)abstract
- The risk determinants of type 1 diabetes, initiators of autoimmune response, mechanisms regulating progress toward beta cell failure, and factors determining time of presentation of clinical diabetes are poorly understood. We investigated changes in the serum metabolome prospectively in children who later progressed to type 1 diabetes. Serum metabolite profiles were compared between sample series drawn from 56 children who progressed to type 1 diabetes and 73 controls who remained nondiabetic and permanently autoantibody negative. Individuals who developed diabetes had reduced serum levels of succinic acid and phosphatidylcholine (PC) at birth, reduced levels of triglycerides and antioxidant ether phospholipids throughout the follow up, and increased levels of proinflammatory lysoPCs several months before seroconversion to autoantibody positivity. The lipid changes were not attributable to HLA-associated genetic risk. The appearance of insulin and glutamic acid decarboxylase autoantibodies was preceded by diminished ketoleucine and elevated glutamic acid. The metabolic profile was partially normalized after the seroconversion. Autoimmunity may thus be a relatively late response to the early metabolic disturbances. Recognition of these preautoimmune alterations may aid in studies of disease pathogenesis and may open a time window for novel type 1 diabetes prevention strategies.
|
|
