| 1. |
- Magnusson, Magnus, et al.
(författare)
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Predicting grey-sided vole occurrence in northern Sweden at multiple spatial scales
- 2013
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Ingår i: Ecology and Evolution. - Hoboken, USA : Wiley-Blackwell Publishing Inc.. - 2045-7758. ; 3:13, s. 4365-4376
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Tidskriftsartikel (refereegranskat)abstract
- Forestry is continually changing the habitats for many forest-dwelling species around the world. The grey-sided vole (Myodes rufocanus) has declined since the 1970s in forests of northern Sweden. Previous studies suggested that this might partly be caused by reduced focal forest patch size due to clear-cutting. Proximity and access to old pine forest and that microhabitats often contains stones have also been suggested previously but never been evaluated at multiple spatial scales. In a field study in 2010–2011 in northern Sweden, we investigated whether occurrence of grey-sided voles would be higher in (1) large focal patches of >60 years old forest, (2) in patches with high connectivity to sur- rounding patches, and (3) in patches in proximity to stone fields. We trapped animals in forest patches in two study areas (V€asterbotten and Norrbotten). At each trap station, we surveyed structural microhabitat characteristics. Land- scape-scale features were investigated using satellite-based forest data combined with geological maps. Unexpectedly, the vole was almost completely absent in Norrbotten. The trap sites in Norrbotten had a considerably lower amount of stone holes compared with sites with voles in V€asterbotten. We suggest this might help to explain the absence in Norrbotten. In V€asterbotten, the distance from forest patches with voles to stone fields was significantly shorter than from patches without voles. In addition, connectivity to surrounding patches and size of the focal forest patches was indeed related to the occurrence of grey-sided voles, with connectivity being the overall best predictor. Our results support previous findings on the importance of large forest patches, but also highlight the importance of connectivity for occurrence of grey-sided voles. The results further suggest that proximity to stone fields increase habitat quality of the forests for the vole and that the presence of stone fields enhances the voles’ ability to move between nearby forest patches through the matrix
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| 2. |
- Abernethy, K. E., et al.
(författare)
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Two steps forward, two steps back : The role of innovation in transforming towards community-based marine resource management in Solomon Islands
- 2014
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Ingår i: Global Environmental Change. - : Elsevier BV. - 0959-3780 .- 1872-9495. ; 28, s. 309-321
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Tidskriftsartikel (refereegranskat)abstract
- In many coastal nations, community-based arrangements for marine resource management (CBRM) are promoted by government, advocated for by non-government actors, and are seen by both as one of the most promising options to achieve sustainable use and secure inshore fisheries and aquatic resources. Although there is an abundant literature on what makes CBRM effective, is it less clear how CBRM is introduced or develops as an idea in a community, and the process of how the idea leads to the adoption of a new resource management approach with supporting institutions. Here we aim to address this gap by applying an explicit process-based approach drawing on innovation history methodology by mapping and analysing the initiation and emergence of CBRM in five fishing-dependent communities in Solomon Islands. We use insights from the literatures on diffusion of innovation and transformability to define phases of the process and help guide the inductive analysis of qualitative data. We show the CBRM institutionalisation processes were non-linear, required specific strategies to move from one phase to the next, and key elements facilitated or hindered movement. Building active support for CBRM within communities depended on the types of events that happened at the beginning of the process and actions taken to sustain this. Matching CBRM to known resource management ideas or other social problems in the community, developing legitimate institutions and decision-making processes, strong continual interactions between key actors and the rest of the community (not necessarily NGO actors), and community members witnessing benefits of CBRM, all contributed to the emergence and diffusion of CBRM in the communities, and helped to overcome barriers to transformative change.
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| 3. |
- Baggio, J. A., et al.
(författare)
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Landscape connectivity and predator-prey population dynamics
- 2011
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Ingår i: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 26:1, s. 33-45
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Tidskriftsartikel (refereegranskat)abstract
- Landscapes are increasingly fragmented, and conservation programs have started to look at network approaches for maintaining populations at a larger scale. We present an agent-based model of predator–prey dynamics where the agents (i.e. the individuals of either the predator or prey population) are able to move between different patches in a landscaped network. We then analyze population level and coexistence probability given node-centrality measures that characterize specific patches. We show that both predator and prey species benefit from living in globally well-connected patches (i.e. with high closeness centrality). However, the maximum number of prey species is reached, on average, at lower closeness centrality levels than for predator species. Hence, prey species benefit from constraints imposed on species movement in fragmented landscapes since they can reproduce with a lesser risk of predation, and their need for using anti-predatory strategies decreases.
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| 4. |
- Barbu, Andreea, et al.
(författare)
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Blood flow in endogenous and transplanted pancreatic islets in anesthetized rats : Effects of lactate and pyruvate
- 2012
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Ingår i: Pancreas. - 0885-3177 .- 1536-4828. ; 41:8, s. 1263-1271
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The objective of this study was to evaluate the effects of exogenously administered lactate and pyruvate on blood perfusion in endogenous and transplanted islets. METHODS: Anesthetized Wistar-Furth rats were given lactate or pyruvate intravenously, and regional blood perfusion was studied 3 or 30 minutes later with a microsphere technique. Separate rats received a 30-minute infusion of pyruvate or lactate into the portal vein before blood flow measurements. We also administered these substances to islet-implanted rats 4 weeks after transplantation and measured graft blood flow with laser Doppler flowmetry. The expression of monocarboxylate transporter 1 and lactate dehydrogenase A was analyzed. RESULTS: The expression of monocarboxylate transporter 1 and lactate dehydrogenase A was markedly up-regulated in transplanted as compared with endogenous islets. Administration of pyruvate, but not lactate, increased mesenteric blood flow after 3 minutes. Pyruvate decreased mesenteric blood flow after 30 minutes, whereas lactate decreased only islet blood flow. These responses were absent in transplanted animals. A continuous intraportal infusion of lactate or pyruvate increased selectively islet blood flow but did not affect blood perfusion of transplanted islets. CONCLUSIONS: Lactate and pyruvate affect islet blood flow through effects mediated by interactions between the liver and the nervous system. Such a response can help adjust the release of islet hormones during excess substrate concentrations.
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| 5. |
- Bergsten, Arvid, 1981-
(författare)
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Fragmented landscapes : Assessment and communication of landscape connectivity in human-dominated landscapes
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This licentiate thesis summarizes the first half of my PhD on the theme of management of fragmented landscapes. The thesis applies – and reflects on the use of – network analysis of connectivity in relation to landscape planning. Relevant theory on knowledge management and spatial ecology is summarized and discussed in connection with two papers.Paper I centers on municipal ecologists and environmental planners in the Stockholm region. They state that connectivity is rarely considered enough in planning and that assessment tools are lacking. Paper I studies the benefits and difficulties of using network analysis to manage connectivity in land-use planning. Among the main difficulties was the choice of model species and access to input data. The main strengths were the graphical and quantitative results, the potential for social learning, identification of critical sites and to relate local planning and ecology to the regional landscape.Paper II applies network methodology to quantify habitat availability of fragmented lichen-type forests in protected areas in northern Sweden. It studies a dynamic landscape that is continuously rearranged by forestry, with consequences that depend on species’ abilities to compete for resources in protected habitats, and to disperse through unprotected mature forest stands. We discuss the results with reference to the planning of forestry and protected areas, and to the resilience of species to patchy disturbance regimes.To end I propose a continuation of research, including a methodological development of network analysis; a sociological study of the acceptance of ecological advice in urban planning; and an integration of social and ecological network analysis to compare patterns of cross-municipal collaboration with landscape connectivity.
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| 6. |
- Bergsten, Arvid, et al.
(författare)
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Protected areas in a landscape dominated by logging - A connectivity analysis that integrates varying protection levels with competition-colonization tradeoffs
- 2013
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 160, s. 279-288
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Tidskriftsartikel (refereegranskat)abstract
- Conservation planning is challenging in landscapes where reoccurring habitat destruction and subsequent recovery affect metapopulation persistence, because different species respond differently to landscape change. By building on a graph-theoretical modeling framework, we here develop a connectivity model of how varying levels of area protection and unprotected areas predetermined for destruction affect species differently depending on (1) their tradeoff in colonization versus habitat utilization ability and (2) their maximum dispersal ability. We apply our model to 20,000 patches of old pine forest in northern Sweden, which host many threatened species but are scattered in a landscape dominated by intensive forestry. Unprotected mature forests stands predestined for logging are treated as adequate but temporarily available habitat for colonization specialists, whereas the same stands are assumed to, at best, serve only as intermediate stepping-stones for habitat specialists as they disperse between long-standing forests in protected areas. Our results show that the effect of habitat fragmentation on metapopulation persistence differs greatly not only depending on the dispersal distance of a particular species, but also on how well it utilizes habitat patches of different longevity. Such traits are discussed with respect to the spatiotemporal planning of habitat protection. Also, we suggest that the negative impacts of logging on biodiversity may be reduced if forestry practice is adjusted to better account for the ecological values of maturing production stands, through spatially explicit modeling of connectivity and of complementarity in the protection gradient.
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| 7. |
- Bergsten, Arvid, 1981-
(författare)
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Spatial complexity and fit between ecology and management : Making sense of patterns in fragmented landscapes
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Avoiding the negative effects of habitat fragmentation on biodiversity is especially challenging when also the management institutions are spatially and administratively distributed. This doctoral thesis introduces five case studies that investigate ecological, social and social-ecological relations in fragmented landscapes. I present new approaches in which research and governance can detect and manage mismatches between landscape ecology and planning. The case studies include urban and forested landscapes where an intense land-use is limiting the connectivity, i.e., the potential for many species to disperse between the remaining patches of habitat. Graph-theoretic (network) models are applied to map connectivity patterns and to estimate the outcome for dispersing species at the patch level and for the whole study system. In particular, the network models are applied to evaluate the spatial complexity and the potential mismatches between ecological connectivity and geographically distributed management institutions like protected areas and municipalities. Interviews with municipal ecologists complement the spatial analysis; revealing some problems and ways forward regarding the communication and integration of ecological knowledge within local spatial-planning agencies. The results also show that network models are useful to identify and communicate critical ecological and social-ecological patterns that call for management attention. I suggest some developments of network models as to include interactions between species and across governance levels. Finally, I conclude that more effort is needed for network models to materialize into ecological learning and transformation in management processes.
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| 8. |
- Bergsten, Arvid, et al.
(författare)
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The problem of spatial fit in social-ecological systems : detecting mismatches between ecological connectivity and land management in an urban region
- 2014
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Ingår i: Ecology & Society. - 1708-3087. ; 19:4
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Tidskriftsartikel (refereegranskat)abstract
- The problem of institutional fit in social-ecological systems has been empirically documented and conceptually discussed for decades, yet there is a shortage of approaches to systematically and quantitatively examine the level of fit. We address this gap, focusing on spatial fit in an urban and peri-urban regional landscape. Such landscapes typically exhibit significant fragmentation of remnant habitats, which can limit critical species dispersal. This may have detrimental effects on species persistence and ecosystem functioning if land use is planned without consideration of the spatial patterns of fragmentation. Managing habitat fragmentation is particularly challenging when the scale of fragmentation reaches beyond the control of single managers, thereby requiring different actors to coordinate their activities to address the problem at the appropriate scale. We present a research approach that maps patterns of collaborations between actors who manage different parts of a landscape, and then relates these patterns to structures of ecological connectivity. We applied our approach to evaluate the fit between a collaborative wetland management network comprising all 26 municipalities in the Stockholm County in Sweden and an ecologically defined network of dispersed but ecologically interconnected wetlands. Many wetlands in this landscape are either intersected by the boundary between two or more municipalities, or are located close to such boundaries, which implies a degree of ecological interconnectedness and a need for intermunicipal coordination related to wetland management across boundaries. We first estimated the level of ecological connectivity between wetlands in neighboring municipalities, and then used this estimate to elaborate the level of social-ecological fit vis-a-vis intermunicipal collaboration. We found that the level of fit was generally weak. Also, we identified critical misalignments of ecological connectivity and intermunicipal collaboration, respectively, as well as collaborations that represented an adequate alignment. These findings inform on where to most effectively allocate limited resources of collaborative capacity to enhance the level of social-ecological fit. Our approach and results are illustrated using maps, which facilitates the potential application of this method in land use planning practice.
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| 9. |
- Blazquez-Cabrera, Sandra, et al.
(författare)
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Indicators of the impacts of habitat loss on connectivity and related conservation priorities : Do they change when habitat patches are defined at different scales?
- 2014
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Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X .- 1872-7034. ; 45, s. 704-716
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Tidskriftsartikel (refereegranskat)abstract
- Delivering indicators of habitat connectivity first requires identifying the habitat units that will be treated as individual entities for spatially explicit analyses. These units can be defined at different spatial scales or hierarchical levels, from single habitat patches to aggregations of multiple neighbor patches. Many studies have assessed the scale sensitivity of landscape-level pattern metrics when changing spatial resolution or extent. However, how patch-level connectivity indicators change across hierarchical levels (independently from modifications in resolution or extent) has been largely overlooked, despite the potentially strong and determinant effects on their outcomes and final uses. We evaluated how the hierarchical level at which habitat units are defined affects two types of outcomes frequently derived from connectivity indicators: (i) the importance values (or estimated amount of decrease in landscape connectivity that would be caused by the loss of certain habitat areas), and (ii) the priority ranking (key areas to conserve to minimize connectivity loss), as given by a selected set of widely used metrics (habitat availability, network centrality, metapopulation capacity). We found that importance values can largely vary depending on how habitat units are defined, suggesting that such results may be flawed by a particular a priori selection of hierarchical levels. However, the identification of which parts of the landscape contain the key connectivity providers (priority ranking) was robust, particularly for those metrics that account for the amount of connectivity within habitat units. We conclude that current connectivity indicators based on patch removals do not allow, considering their scale dependence, to consistently assess the magnitude of connectivity decrease resulting from large-scale habitat loss, but that they can be used with much more confidence for detecting those key areas that most contribute to maintain current connectivity levels.
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| 10. |
- Bodin, Örjan, et al.
(författare)
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A social relational approach to natural resource governance
- 2011
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Ingår i: Social Networks and Natural Resource Management. - Cambridge : Cambridge University Press. - 052176629X - 9780521766296 - 0521146232 - 9780521146234 - 9781139100793 ; , s. 1-54
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Bokkapitel (refereegranskat)
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