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- Charlier, Johan
(författare)
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Spatio-temporal genetic variation in wild animal and plant populations in Sweden and its relevance for conservation genetic monitoring
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human impact on the world’s ecosystems is massive, resulting in habitat destruction and fragmentation that strongly affects the future survival of non-human life forms. Typically, biodiversity loss at the genetic level is much less recognized as compared to the levels of species and ecosystems, and information on reduction of natural gene pools is frequently missing unless coupled with loss of an entire species. To detect reductions or changes in genetic composition, genetic variation must be studied over time (genetic monitoring). Presently, monitoring is to a larger scale implemented at the ecosystem and species levels to identify biodiversity loss, whereas monitoring programs at the gene level are still missing for most species.This thesis focuses on “conservation genetic monitoring”, which I and my co-authors have defined to include identifying and safeguarding gene level biodiversity for the implementation of the Convention of Biological Diversity (CBD). Amount of genetic variation, genetic composition, and spatial genetic structure must be systematically studied over time to detect potential changes of these parameters that can reflect in loss of gene level biodiversity.Paper I of this thesis suggests categories of species for which monitoring genetic diversity appears particularly urgent on the basis of e.g. level of exploitation and threat status. We stress that a basic description of a species´ spatial distribution of genetic variation at some point in time represents a primary prerequisite for future monitoring. Therefore, literature searches were conducted to collect information on the current knowledge regarding spatio-temporal genetic variation in wild animal and plant populations in Sweden. Basic starting points for “conservation genetic monitoring” of Swedish species is fairly limited. A total of 775 scientific studies including genetic information for a total of 374 species were found, but most of them (277) were directed towards only a few species of bony fishes and forest trees. Only four percent of the studies also included temporally spaced samples. For several species for which conservation genetic monitoring is considered particularly urgent genetic data is missing. One such species is the moose (Alces alces), the demography of which is almost completely controlled by man. Various moose hunting strategies are expected to directly affect the genetically effective population size and generation interval, factors that govern the rate of loss of genetic variation. These potential effects are insufficiently recognized among managers, and genetic data is largely missing for this ecologically and socio-economically important mammal. Paper II focuses on the generation of basic information on the spatial genetic structure of the Swedish moose population using six microsatellite loci. The results indicate that the moose in Sweden does not constitute a single panmictic unit, and there are indications of a local bottleneck in one area. For an evolutionary sustainable management of the moose, it is important that management and genetic groupings coincide.
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| 2. |
- Favati, Anna, 1980-
(författare)
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Social dominance and personality in male fowl (Gallus gallus domesticus)
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Individuals in social species commonly form dominance relationships among each other, andare often observed to differ in behaviour depending on their social status. However, whethersuch behavioural differences are a consequence of dominance position, or also a cause to it,remains unclear. In this thesis I therefore investigated two perspectives of the relationshipbetween social dominance and personality in the domestic fowl (Gallus gallus domesticus), asocial species that forms relatively stable dominance hierarchies. In paper I I investigated theinfluence of social status on the expression and consistency of behaviours by experimentallychanging status between repeated personality assays. The level of vigilance, activity andexploration changed with social status, while boldness and territorial crows appeared asstable individual properties, independent of status. These results showed that social statuscontribute to both variation and consistency in behavioural responses. Social status shouldtherefore be taken into account when investigating and interpreting variation in personality.In paper II I showed that behaviour in a novel arena test and during encounter with anopponent can predict social status, more specifically that fast exploration and aggressivenesspredicted a dominant social position. Together, these results highlight the dynamics of thetwo-way relationship between social position and individual behaviour and indicate thatindividual behaviour can both be a cause and a consequence of social status.
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| 3. |
- Andersson, Mathias H., 1976-
(författare)
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Man-made structures as habitat for marine faunal assemblages
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Artificial reefs are structures placed in the sea to promote marine life. Although constructions such as oil-rigs, wind farms, bridges and pier pilings are built for other purposes, they could be regarded as artificial reefs as they add new surfaces in the oceans, susceptible to colonization by marine organism. One of the most common constructions in the oceans is cylindrical structures of different materials. Most research of artificial reefs has been conducted in tropical and temperate water and experience and conclusions cannot always be applied to colder waters. Man-made constructions are common in northern European seas, however, few studies are presented in the scientific literature on their impact on the marine ecosystem. The aim of this thesis was to study cylindrical structures of different scale and materials, in order to determine their effect on local fish, algae and sessile invertebrate assemblages. These structures were offshore wind turbines, and pillars of different materials (concrete and steel), situated at the Swedish east and west coast, respectively. They add vertical surfaces into the otherwise empty water column, increasing the probability for fish and invertebrate larvae as well as algae spores and propagules to encounter these high structures, compared to low profile natural or other artificial reefs. Fish species usually associated with rocky reefs and algae communities, i.e. the two spotted goby and the goldsinny-wrasse, showed an increase in abundance around the introduced cylindrical structures. Similar effect on fish species were found on both the Swedish east and west coast. The observed increase in fish densities seemed to be caused by added habitat since the pillars and wind turbines provide shelter from predators as well as increased food availability. The latter was either due to the fouling assemblage or change in water movement. The environment created by the introduced structures functions both as nursery and spawning areas since juveniles, adults and gravid fish were recorded in close association with the structures. The fouling community on the vertical surfaces did not resemble the natural assemblages and a difference in recruitment and succession on the pillars of different materials were observed. Further, dissimilar fouling assemblages were observed with other species dominating the assemblages on a fifty year old light-house foundation compared to the seven year old wind turbines, both located in the same area. The sessile filter feeding invertebrates located on the foundations have an advantage in food accessibility towards individuals at the seabed, as the organisms on the foundations are constantly susceptible to the water passing by. In addition, by adding offshore structures in areas previously lacking hard surfaces, non-indigenous species could find new available habitat or the foundations can function as stepping stones into new geographical regions.
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| 4. |
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| 5. |
- Sangster, George
(författare)
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Controversies over taxonomic and nomenclatural instability: an empirical approach
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Taxonomic names serve two important functions: they reflect hypotheses about the existence of taxa, and they serve as the primary means to communicate about biodiversity. The dual purpose of names is a source of conflict and misunderstanding among taxonomists and end-users of taxonomy. In recent years, proposals have been made to curb nomenclatural change both at the species level and at higher taxonomic levels. However, the causes and extent of taxonomic and nomenclatural instability are poorly known. In this thesis, I focus on two major controversies in systematics. The first of these deals with the question whether taxonomic changes at the species level are real or merely caused by a shift of the species concept. The second deals with the question whether the current rank-based (Linnaean) nomenclatural system should be replaced by an alternative nomenclatural system. Both debates have been dominated by conflicting theoretical arguments in high-profile journals, but with very little input from quantitative empirical studies. In manuscript 1, I address the highly influential claim that recent increases of the number of vertebrate species are not real but are due to reinterpretations of previous data under a Phylogenetic Species Concept (PSC). To this end, I examine 747 proposals to change the taxonomic rank of birds in the period 1950–2007. The trend to recognize more species of birds started at least two decades before the introduction of PSCs. Most (85%) newly recognized species were supported by new taxonomic data. Proposals to recognize more species resulted from application of all six major taxonomic criteria. Many newly recognized species (63%) were not based exclusively on PSC-based criteria (diagnosability, monophyly and exclusive coalescence of gene trees). Therefore, this study finds no empirical support for the idea that the increase in species is primarily epistemological rather than data-driven. This study shows that previous claims about the causes and effects of taxonomic inflation lack empirical support. I argue that a more appropriate term for the increase in species is ‘taxonomic progress’. In manuscript 2, I present a quantitative analysis of nomenclatural instability in birds. The dataset included 826 name-taxon associations in seven major classifications of birds published between 1934 and 2007. High levels of synonymy (38% of taxa, affecting 68% of names) and homonymy (18% of names, affecting 46% of taxa) were found. On average, supra-generic taxa accepted in all seven classifications are known by 3.3 different names, and very few (2%) of these taxa are known by a single name. A significant inverse relationship between taxonomic stability and nomenclatural stability was found. Furthermore, each new classification introduced additional names for previously recognized taxa and re-applied previous names to other taxa. Overall, 94% of synonyms and 69% of homonyms were caused by differences in opinion among taxonomists about the rank of taxa. In addition, variation in the taxonomic contents of names did not become less with increased recognition of names. These findings argue against recent claims that taxonomists using rank-based nomenclature spontaneously settle on a consensus about the choice of taxon names. These results further indicate that rank-based nomenclature so far has failed to accomplish a reasonably stable association of taxonomic names and clades. These studies show that at species rank, there is a strong empirical basis for taxonomic (and hence nomenclatural) change. As a consequence, pleas for stability at the species level are unrealistic. However, at higher ranks, the empirical basis for nomenclatural change is weak, and thus attempts should be made to curb unnecessary nomenclatural instability (e.g. by adopting phylogenetic nomenclature). These results underscore that empirical studies of taxonomic practise may usefully inform theoretical debates.
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| 6. |
- Appelqvist, Thomas
(författare)
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Åsunden - lövrike
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Som ett led i att förverkliga miljömålet ”Levande Skogar” har Skogsstyrelsen och Länsstyrelsen startat ett pilotförsök i det sjörika landskapet runt Åsunden och Sämsjön. Här finns många värdefulla lövskogar. Projektet syftar till att hitta en bra metod för att på ett mer sammanhållet sätt värna och utveckla natur- och kulturvärden i denna trakt. Det är önskvärt att alla de aktörer som arbetar med skog och träd i detta landskap, som kommunen, privata skogsägare, naturvården och kulturminnesvården samarbetar mot gemensamma och fastställda mål. Denna skrift är ett försök att konkretisera en del av dessa mål. Se även rapporten Lövskogarna i Åsunden-trakten (2009-28).
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