| 1. |
- Bergsten, Arvid, et al.
(författare)
-
Protected areas in a landscape dominated by logging - A connectivity analysis that integrates varying protection levels with competition-colonization tradeoffs
- 2013
-
Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 160, s. 279-288
-
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.
|
|
| 2. |
- Bergsten, Arvid, 1981-
(författare)
-
Spatial complexity and fit between ecology and management : Making sense of patterns in fragmented landscapes
- 2013
-
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.
|
|
| 3. |
- Bergsten, Arvid, et al.
(författare)
-
To model the landscape as a network : A practitioner's perspective
- 2013
-
Ingår i: Landscape and Urban Planning. - : Elsevier BV. - 0169-2046 .- 1872-6062. ; 119, s. 35-43
-
Tidskriftsartikel (refereegranskat)abstract
- Recent years have shown a rapid increase in the number of published studies that advocate network analysis (graph theory) to ecologically manage landscapes that suffer from fragmentation and loss of connectivity. This paper studies the reasons, benefits and difficulties of using network analysis to manage landscape fragmentation in the practice of land-use planning. The results are based on interviews with thirteen municipal ecologists and environmental planners in Stockholm, Sweden, who had been introduced to a GIS-tool for network-based connectivity analysis. Our results indicate that fragmentation is not considered enough in municipal planning and demonstrate that none of the interviewed practitioners used systematic methods to assess landscape connectivity. The practitioners anticipate that network-level and patch-level connectivity measures and maps would help them to communicate the meaning and implications of connectivity to other actors in the planning process, and to better assess the importance of certain habitats affected by detailed plans. The main difficulties of implementing network-based connectivity analyses reported by the respondents related to the choice of focal species and the lack of model input in terms of landscape data and dispersal distances. The main strengths were expressed by the practitioners as graphical, quantitative and credible results; the ability to compare planning alternatives and to find critical sites in a more objective manner than today; and to relate local planning and ecology to the regional structure of the landscape. Many respondents stressed the role of fragmentation assessments in the endeavor to overcome current spatial mismatches of ecological and administrative scales.
|
|
| 4. |
- Magnusson, Magnus, et al.
(författare)
-
Predicting grey-sided vole occurrence in northern Sweden at multiple spatial scales
- 2013
-
Ingår i: Ecology and Evolution. - Hoboken, USA : Wiley-Blackwell Publishing Inc.. - 2045-7758. ; 3:13, s. 4365-4376
-
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
|
|
