| 1. |
- Andersson, Erik, et al.
(författare)
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Practical tool for landscape planning? An empirical investigation of network based models of habitat fragmentation.
- 2009
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 32:1, s. 123-132
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Tidskriftsartikel (refereegranskat)abstract
- This study presents a graph-theoretical modelling approach using daily movements and habitat demands of different target bird species in an urban context to assess: 1) habitable land cover types, 2) threshold distances between patches of habitat, 3) the required minimum accessible habitat areas and 4) the effects of barriers and stepping stones. The modelling approach is tested using empirical data from field surveys in the urban area of Stockholm, Sweden. The results show that groups of small habitat patches can house the same species as larger contiguous patches as long as they are perceived as functionally connected by the inhabitant organisms. Furthermore, we found that binary habitat/non-habitat representations of the landscape could roughly explain the variation in species occurrence, as long as habitat was properly defined. However, the explanatory power of the landscape models increased when features of matrix heterogeneity such as stepping stones and barriers were accounted for. Synthesis and application: in a world where forest ecosystems are becoming increasingly fragmented there is an urgent need to find comprehensive and scientifically relevant methods for managing and planning ecosystems. This study shows that: 1) groups of well placed small habitat patches can, together, be sufficient to attract birds in intensively developed areas, 2) the presented modelling approach can help identify such groups of patches, 3) matrix heterogeneity should preferably be accounted for, and 4) proper assessments of habitable land cover types are important. Finally, we argue that the modelling approach applied here may substantially improve landscape management and planning at scales ranging from whole landscapes down to neighbourhoods.
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| 2. |
- Bodin, Per, et al.
(författare)
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Guidance, navigation, and control experiments on the PRISMA in-orbit test bed
- 2007
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Ingår i: 58th International Astronautical Congress, IAC-07-C1. - 9781605601502 ; , s. 4461-4470
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Konferensbidrag (refereegranskat)abstract
- PRISMA will demonstrate Guidance, Navigation and Control strategies for advanced autonomous formation flying and rendezvous. The Swedish Space Corporation (SSC) is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB). The project is further supported by the German Aerospace Center (DLR), the Technical University of Denmark (DTU), and the French Space Agency (CNES). PRISMA consists of two spacecraft: MAIN and TARGET. The MAIN satellite is 3-axis stabilized and has full 3D delta-V maneuverability that is independent of the spacecraft's attitude. The TARGET satellite has a simplified, yet 3-axis stabilizing, magnetic attitude control system and no orbit maneuver capability. This paper presents the PRISMA Guidance, Navigation, and Control (GNC) subsystem. The paper gives a mission summary and an overview of the GNC subsystem with its hardware and software configuration. It also explains how the orbit control functions contain advanced fuel optimal Model Predictive Control (MPC). It is shown how the GNC software is developed using model based automatic coding technology implemented with Matlab/Simulink. The paper then summarizes the different GNC experiments to be performed by SSC. Finally, an overview of the test approach for the subsystem is given.
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| 3. |
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| 4. |
- Bodin, Örjan, 1969-
(författare)
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A network perspective on ecosystems, societies and natural resource management
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis employs a network perspective in studying ecosystems and natural resource management. It explores the structural characteristics of social and/or ecological networks and their implications on societies’ and ecosystems’ ability to adapt to change and to cope with disturbances while still maintaining essential functions and structures (i.e. resilience).Paper I introduces terminology from the network sciences and puts these into the context of ecology and natural resource management. Paper II and III focus on habitat fragmentation and how it affects an agricultural landscape in southern Madagascar. Two ecosystem services were addressed: (1) crop pollination by bees, and (2) seed dispersal by ring-tailed lemurs. It is shown that the fraction of the studied landscape presently covered by both crop pollination and seed dispersal is surprisingly high, but that further removal of the smallest habitat patches in the study area could have a severe negative impact on the landscape’s capacity to support these ecosystem services.In Papers IV and V, the network approach is used to study social networks and the impact they may have on the management of natural resources. In Paper IV it is found that social networks of low- to moderate link densities (among managers) significantly increase the probability for relatively high and stable utility returns whereas high link densities cause occasional large-scale ecological crises between periods of stable and excessively high utility returns. In Paper V, social networks of a rural fishing community in eastern Africa were analyzed. The results indicate that patterns of communication partly explain the distribution of ecological knowledge among villagers, and that gear type used by small-scale coastal fishermen strongly correlates with their patterns of communication. The results also show that groups most central in the network, and hence potentially most influential, are dominated by one type of fishermen.
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| 5. |
- Bodin, Örjan
(författare)
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Ecological Topology and Networks
- 2009
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Ingår i: Encyclopedia of Complexity and Systems Science. - New York : Springer. - 9780387758886 ; , s. 2728-2744
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
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| 7. |
- Bodin, Örjan
(författare)
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Prioritizing habitat patches for conservation in fragmented landscapes/townscapes using network based models and analyses.
- 2009
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Ingår i: Sustainable Development and Planning IV (vol1.). - : WIT Press. - 9781845641818 ; , s. 109-118
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- To preserve biodiversity in highly fragmented landscapes, it is crucial to conserve and possibly improve the connectivity among remaining habitat patches.However, multiple users are competing for a limited amount of land, and conservation efforts subsequently need to be efficiently directed to maximize biodiversity given limited resources.In terms of connectivity, this could be expressed as to which habitat patches do we really need to preserve, and which patches could we lose without facing any significant negative effects on connectivity? Network-based models of fragmented landscapes provide for comprehensive visualizations and analyses of landscape connectivity that could help in prioritizing habitat patches for conservation.This is especially valuable in a planning context where many different types of agents are typically involved, thus emphasizing the importance of being able to present key ecological implications of different spatially explicit habitat configurations in a easily understandable way. Here, three different aspects of landscape connectivity are presented, all suggested as being particularly suitable for network-based modeling approaches. These are: (i) estimating to what degree the landscapes spatial configuration enables re-colonization following local extinctions; (ii) identifying clusters of patches that together form sufficient habitat; and (iii) identifying key-stone patches that are crucial in providing connectivity
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| 8. |
- Bodin, Örjan, et al.
(författare)
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Social networks in natural resource management : What is there to learn from a structural perspective?
- 2006
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Ingår i: Ecology & Society. - : Resilience Alliance, Inc.. - 1708-3087. ; 11:2, s. r2-
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Tidskriftsartikel (refereegranskat)abstract
- Social networks among actors and stakeholders are gaining attention in studies of natural resource management, particularly those of adaptive management based on different forms of participation and co-management. In this sense, social networks have primarily been envisioned as enabling different actors to collaborate and coordinate management efforts. Here, we continue the discussion initiated by Newman and Dale (2005), which highlighted the fact that not all social networks are created equal. We discuss the relation between some structural characteristics and functions of social networks with respect to natural resource management, thus focusing on structural implications that are often overlooked when studying social networks within the context of natural resource management. We present several network measures used to quantify structural characteristics of social networks and link them to a number of features such as learning, leadership, and trust, which are identified as important in natural resource management. We show schematically that there may be inherent juxtapositions among different structural characteristics that need to be balanced in what we envision as social network structures conducive to adaptive co-management of natural resources. We argue that it is essential to develop an understanding of the effects that different structural characteristics of social networks have on natural resource management.
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| 9. |
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| 10. |
- Bodin, Örjan, et al.
(författare)
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The value of small size: loss of forest patches and ecological thresholds in southern Madagascar
- 2006
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Ingår i: Ecological Applications. - : the Ecological Society of America. - 1051-0761 .- 1939-5582. ; 16:2, s. 440-451
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Tidskriftsartikel (refereegranskat)abstract
- Many services generated by forest ecosystems provide essential support for human well-being. However, the vulnerability of these services to environmental change such as forest fragmentation are still poorly understood. We present spatial modeling of the generation of ecosystem services in a human-dominated landscape where forest habitat patches, protected by local taboos, are located in a matrix of cultivated land in southern Madagascar. Two ecosystem services dependent on the forest habitats were addressed: (1) crop pollination services by wild and semidomesticated bees (Apoidea), essential for local crop production of, for example, beans, and (2) seed dispersal services based on the presence of ring-tailed lemurs (Lemur catta). We studied the vulnerability of these ecosystem services to a plausible scenario of successive destruction of the smallest habitat patches. Our results indicate that, in spite of the fragmented nature of the landscape, the fraction of the landscape presently covered by both crop pollination and seed dispersal services is surprisingly high. It seems that the taboo system, though indirectly and unintentionally, contributes to upholding the generation of these services by protecting the forest patches. Both services are, however, predicted to be very vulnerable to the successive removal of small patches. For crop pollination, the rate of decrease in cover was significant even when only the smallest habitat patches were removed. The capacity for seed dispersal across the landscape displayed several thresholds with habitat patch removal. Our results suggest that, in order to maintain capacity for seed dispersal across the landscape and crop pollination cover in southern Androy, the geographical location of the remaining forest patches is more crucial than their size. We argue that in heavily fragmented production landscapes, small forest patches should increasingly be viewed as essential for maintaining ecosystem services, such as agricultural production, and also should be considered in the ongoing process of tripling the area of protected habitats in Madagascar.
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