Munin: Doktorgradsavhandlinger (BFE-fak)

Oil and gas activity in the high north: Economic opportunities and political dependencies

Harsem, Øistein Breiland (Doctoral thesis; Doktorgradsavhandling, 07-Jun-2013)

[+]

Determinants and effects of moth population dynamics in altitudinal gradients in northern Fennoscandia

Schott, Tino (Doctoral thesis; Doktorgradsavhandling, 21-May-2013)

[+]

Abstract:	The aim of this PhD-project has been to increase our knowledge of trophic interactions along altitudinal gradients in a system of sympatric, cyclically outbreaking geometrid moth species in sub-arctic, coastal birch forest in northern Norway. The project resulted in four scientific publications; two sub-studies focused on the causal effect of natural enemies on the observed complex spatio-temporal dynamics of the moth species (Papers 1 & 2). The other two sub-studies investigated the ecological effects of variable moth larvae densities as a resource for predators in the sub-Arctic ecosystem (Papers 3 & 4). In paper 1, we rejected the hypothesis that larval parasitoids might terminate moth population peaks, one of the most important hypotheses on insect population regulation. We, however, found that larval parasitoids can influence local spatial variation in moth population density. Hence, we concluded that spatial replication of sampling sites is crucial to arrive at non-biased estimates for the temporal effect of larval parasitoids on host populations. The long enduring debate on the regulation potential of parasitoids on insect populations in the scientific literature may be viewed in light of our findings. Similarly, in Paper 2, we tested if the often-observed spatial outbreak patterns of moth populations might be a result of release from invertebrate predators. Along mountain slopes, moth outbreaks in northern Fennoscandia often occur close to the tree line, and we tested if the abundance of ground dwelling invertebrate predators was inversely correlated with altitude, testing the assumption that moth outbreaks may be a result of reduced predation impact at high altitudes. As our analyses could not reveal this predicted pattern, we rejected the hypothesis. Consequently, the first two sub-studies delimitated the number of candidate factors that might shape Fennoscandian moth dynamics by reevaluating the role of larval parasitoids and ground-dwelling invertebrate predators. In paper 3, we reanalyzed the data from Paper 1 from the parasitoid's perspective by determining the dependencies of individual parasitoid species to host densities. For comparison, we also estimated the strength of effects hidden in the spatial and temporal attributes of altitude and year on parasitoid prevalence rates. We found that altitude and year, rather than host density, explained by far most of the extra-binomial variation in the parasitoid prevalence data. Hence, we concluded that unknown factors, which co-vary with altitude and year, dominate the prevalence dynamics of the larval parasitoids in our study and, consequently, act to decouple parasitoid dynamics from the dynamics of their hosts. Moth larvae as a resource for predators were also the focal issue in Paper 4, which focused on the importance of prey availability and forest phenology for breeding parameters in the two passerine birds great tit and pied flycatcher. The study was based on the phenological conflict that spring arrives in mountain slopes first at low altitude, while the bird's main food resource during the breeding season (i.e. moth larvae) often dominates forest habitat at higher altitude. Thus, we tested if passerine birds select breeding habitat according to the onset of spring or the availability of moth larvae and if the two bird species differed in this respect. We found that the phenological timing was the main driving force for both species when selecting breeding habitat lowest in the gradients where spring arrived first. However, also the positive correlations with moth larvae density appeared to be significant in our analyses. The main difference between the two species was found in the timing strategy for egg laying and size of clutches, which might make the great tit more prone to mismatch during springs of lower temperature. In addition, while nest box occupancy decreased with altitude in both species, the same relationship with respect to clutch size was only found for pied flycatchers, but not for great tits. Finally, great tits were more prone to fail during their breeding attempt and we concluded that the pied flycatcher, by laying eggs up to two weeks after great tits, appears to be the better adapted species with respect to breedig at sub-arctic conditions. This PhD-thesis strengthens the view that so-called top-down interactions in the ecological moth system in northern Fennoscandia cannot explain complex moth population dynamics, but that moth larvae can be regarded as a valuable resource for species at other trophic levels. The consistent dominance of altitude and year in all our analyses, on the other hand, suggests that explanations for the complex spatio-temporal moth population dynamics ought to be looked for in mechanisms ruled by environmentally governed processes such as phenology.
Description:	The papers of this thesis are not available in Munin: 1. Schott T., Hagen S.B., Ims R.A. & Yoccoz N.G.: 'Are population outbreaks in sub-arctic geometrids terminated by larval parasitoids?', Journal of Animal Ecology (2010), vol.79:701-708. Available at http://dx.doi.org/10.1111/j.1365-2656.2010.01673.x 2. Schott T., Kapari L., Hagen S.B., Vindstad O.P.L., Jepsen J.U. & Ims R.A.: 'Predator release from invertebrate generalists does not explain geometrid moth outbreaks at high altitudes', The Canadian Entomologist (2013), vol.145:184-192. Available at http://dx.doi.org/10.4039/tce.2012.109 3. Schott T., Ims R.A., Hagen S.B. & Yoccoz N.G.: 'Sources of variation in larval parasitism of two symmetrically outbreaking birch forest defoliators', Ecological Entomology (2012), vol. 37:471-479. Available at http://dx.doi.org/10.1111/j.1365-2311.2012.01386.x 4. Schott T., Svavarsdottir S., Hagen S.B., Kapari L., Vindstad O.P.L., Biuw M., Jepsen J.U. & Ims R.A.: 'Coping with variation in prey abundance and phenology: Comparative breeding performance of two passerines at the northern limit of their geographic range' (manuscript).
URI:	http://hdl.handle.net/10037/5159

File(s) in this item: 1

thesis.pdf (3.351Mb)

Seabirds, climate and prey. A population study of two seabird species.

Reiertsen, Tone Kristin (Doctoral thesis; Doktorgradsavhandling, 30-May-2013)

[+]

Abstract:	Many seabird populations have declined dramatically over recent decades, and studying the demography and population dynamic in seabird populations is important to gaining a better understanding of causes and mechanisms lying behind such changes and to identify targets for conservation and management. Climate and prey availability are known to affect demography and population dynamics of seabirds. Climate is now changing and a warming of the ocean may lead to changed availability of prey species and will affect seabirds through their demographic traits and ultimately their abundance and distribution. The main aim of this thesis was to study the impact of climate and prey abundance on seabird demography and population dynamics, using two seabird populations; the black-legged kittiwake Rissa tridactyla and the Common guillemot Uria aalge breeding on Hornøya in NE Norway whose populations are declining in Norway. The first question addressed in the thesis was how environmental conditions affect the demography and population variability of kittiwakes and guillemots. The non-breeding distribution of the kittiwakes has recently been documented using year-round light-based geolocators, and we investigated the relationship between environmental conditions in these non-breeding areas and the adult survival of kittiwakes breeding on Hornøya. We found for the kittiwakes that Thecosomata, a group of pteropods (also called sea butterflies), in the Grand Banks/Labrador Sea area in winter and the capelin Mallotus villosus stock in Barents Sea in the pre-breeding season together explained as much as 52 % of the yearly variation in adult survival rate. Further we found that the availability of 0-group cod Gadus morhua was a much more important factor affecting demography and determining the population dynamics of the common guillemot in the Barents Sea than previously considered. The second question was which demographic trait drives the population dynamics of the steeply declining kittiwake population on Hornøya. We showed, by using demographic matrix modeling and LTRE analyses, that both the variability in breeding success (and hence the recruitment to the population) and adult survival rate contributed to the steep decline in the kittiwake population on Hornøya. The strong reduction in breeding success (and hence a decline in recruitment to the population) had, however, the highest impact. The final question was whether populations can adapt to environmental changes through micro-evolutionary processes. This study found that adult survival of the two different genetic colour morphs (bridled and non-bridled morph) of the common guillemot responded differently to yearly variability in sea surface temperatures. Colour dimorphism may, in this case serve as a genetic marker in the guillemot population, and can potentially visualize the direction of selection and micro-evolutionary processes driven by climate. The studies in this thesis contribute to the understanding of the population dynamic of two declining seabird species which are both on the Norwegian Red List, and to the directions of future studies and conservation targets of both species.
Description:	Papers 1, 2 and 4 of this thesis are not available in Munin: 1. Reiertsen, T.K., Erikstad, K.E., Anker-Nilssen, T., Barrett, R.T., Boulinier, T., Frederiksen, M., González-Solís, J., Gremillet, D., Johns, D., Moe, B., Ponchon, A., Sandvik, H., Skern-Mauritzen, M. and Yoccoz, N.G.: 'Prey density in non-breeding areas affects adult survival of black-legged kittiwakes Rissa tridactyla breeding in the southern Barents Sea' (manuscript). 2. Reiertsen, T.K., Barrett, R.T. and Erikstad, K.E.: 'Kittiwakes on the cliff edge: a demographic analysis of a steeply declining arctic kittiwake population' (manuscript). 4. Reiertsen, T.K., Erikstad, K.., Barrett, R.obert T., Sandvik, H. and Yoccoz, N.: 'Climate fluctuations and differential survival of bridled and non-bridled Common Guillemots Uria aalge', Ecosphere (2013), vol. 3(6). Available at http://dx.doi.org/10.1890/ES12-00031R
URI:	http://hdl.handle.net/10037/5158

File(s) in this item: 2

paper_3.pdf (943.5Kb)

thesis.pdf (1.264Mb)

Bureaucrats and Boundaries. The changing intersection between experts, local communities and environmental administration in nature protection

Bay-Larsen, Ingrid Agathe (Doctoral thesis; Doktorgradsavhandling, 08-Mar-2013)

[+]

Abstract:	Loss of biodiversity and fragmentation of habitats are two of the world’s persistent environmental problems. This is due to the emerging complexities, uncertainties and questions of societal scale in both defining and resolving the problems. One of the challenges connected to resolving these problems pertains to the divide between the local level, which carries the costs of restrictions and regulations of use and resource extraction, and the national and global levels, where benefits are realized in terms of multiple ecosystem services (also for future generations). Another salient challenge pertains to the divide between the aggregate level of scientific expertise about the environment and the concepts and capacities of stakeholders and their resource use. These are well-known divides that typically emerge in analyses of coupled social-ecological systems. Resolving environmental problems therefore takes place in the intersection between multiple scales, actors, agencies and competencies. The local and national/international levels are likely to differ in their perceptions of environmental problems and in their perceived needs and strategies for environmental protection. Deliberative environmental governance is increasingly a focus of the international environmental agenda, and a wide range of political programs and efforts have been launched to implement and increase the efficacy and legitimacy of environmental protection. The shift from environmental governing to governance is placing more emphasis on sectors, stakeholders and knowledge across multiple scales in environmental and other policy areas. This has added the dimension of vertical divides to persistent environmental problems in addition to the horizontal ones described above. The integration of actors, agencies and competencies across both the horizontal and vertical divides influences decision-making processes and the role and position of the environmental administration. Compared with environmental governing, deliberative environmental governance places less importance on legal instruments and formal rules, new roles for civil society, as well as trust in other institutions' expert knowledge. These shifts have implications for how the environmental administration maintains power and legitimacy for their decisions and programs. This thesis asks how Norwegian environmental administration responds to such a shift from governing to governance, in particular with respect to the empowerment of local user interests and the implementation of expert knowledge in the protection of areas and biodiversity. It also addresses how the administration utilizes the potential for combining national and local ambitions and perceptions of environmental policy. The overall research question is examined in three published articles, each answering one sub-question. Findings from these articles show that: 1) there are differing responses at the regional and national administrative levels to challenges of accountability and competence resulting from the decentralization of power; 2) the environmental administration struggles to address the inherent limitations in expert knowledge applied in environmental planning, particularly with respect to the complexities of environmental problems and how to handle scientific uncertainties; and 3) the contesters of environmental protection apply various power resources to challenge the comprehension of environmental problems upon which environmental policy rests. This thesis clearly shows how the ideals embedded in deliberative environmental governance are quickly faced with political, juridical and scientific complexities in the administrative reality. A paradox evolves as diverging strategies at administrative levels, and the lack of strategies to cope with the limitations of science, may weaken their power and position. Instead of protecting their role and the mandate of environmental programs, a further marginalizing of environmental protection may be the consequence. This thesis suggests that administrative strategies and guidelines also need to be amended in order to solve persistent environmental problems. Lessons learned from this thesis include the need to harmonize strategies across administrative levels and to develop guidelines to differentiate between users that are potential allies for nature protection (as embedded in international environmental conventions), versus the users that are capable of marginalizing the environmental administration and their legitimacy and efficiency. Environmental administration at both levels also needs to develop strategies to manage the limitations of scientific expertise (complexities and uncertainties) so that these are not used strategically to contest environmental programs. Finally, this thesis shows how the environmental administration not only deals with the protection of areas and nature, but also with the protection of discourses that regulate the administrative power, the boundaries between science and policy and the comprehension of coupled social-ecological systems.
Description:	The papers of this thesis are not available in Munin: 1. Ingrid Bay-Larsen: 'The conservationists’ concerns: on national administration response to integrated use and protection planning', Local Environment (2010), vol.15(4):357-371. Available at http://dx.doi.org/10.1080/13549831003677688> 2. Ingrid Bay-Larsen: 'The Premises and Promises of Trolls in Norwegian Biodiversity Preservation', Environmental Management (2012), vol. 49(5):942-953 . Available at http://dx.doi.org/10.1007/s00267-012-9837-2 3. Ingrid Bay-Larsen: 'The constitution of power in Norway’s protected areas: on shore and in the sea', Local Environment (2012), vol. 17(3):331–347. Available at http://dx.doi.org/10.1080/13549839.2012.665862
URI:	http://hdl.handle.net/10037/5071

File(s) in this item: 1

thesis.pdf (1.187Mb)

Doktorgradsavhandlinger (BFE-fak)

DSpace/Manakin Repository

Doktorgradsavhandlinger (BFE-fak)

Recent additions

Search Munin

Browse

All of Munin

This Collection

Help

Abstract:	Adjuvanter benyttes for å styrke/bedre immunresponsen ved vaksinering. PLGA (poly(lactic-co-glycolic)acid) er en biologisk nedbrytbar polymer som innehar adjuvantegenskaper når den benyttes i form av partikler. Som vaksinebærere kan partikler beskytte mot nedbryting, stimulere inflammatoriske immunresponser og initiere adaptive immunresponser. Partikler er også vist å gi økt opptak i ulike celletyper. Avhandlingen tar for seg PLGA partikler som bærere/adjuvanter for DNA vaksinering, en vaksineform som har vist potensiale for bekjempelse av virussykdommer blant ulike fiskearter. PLGA partikler med plasmid ble injisert intramuskulært i atlantisk laks. Rent plasmid førte til høyest uttrykk av transgen. Bruk av partikler ga sterke inflammatoriske responser, også sammenlignet med en oljeadjuvant. Partikler med plasmid induserte også antivirale responser. Resultatene tyder på at inkapsulering i PLGA partikler kan bidra til å styrke immunresponser som kan være gunstige ved DNA vaksinering.
Description:	The papers of this thesis are not available in Munin: 1. B. N. Fredriksen, L. B. Hølvold, J. Bøgwald and R. A. Dalmo: 'Optimization of formulation variables to increase antigen entrapment in PLGA particles', Polymer-Plastics Technology and Engineering (2012), vol.51(14):1468-1473. Available at http://dx.doi.org/10.1080/03602559.2012.715358 2. L. B. Hølvold, B. N. Fredriksen, J. Bøgwald and R. A. Dalmo: 'Transgene and immune gene expression following intramuscular injection of Atlantic salmon (Salmo salar L.) with DNA-releasing PLGA nano- and microparticles' (manuscript)
URI:	http://hdl.handle.net/10037/5157