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The Late Permian mass extinction occurring at 252.6 ± 0.2 Ma is the most severe Phanerozoic extinction event and was preceded and followed by additional disturbances. Patterns and processes of extinction and recovery of marine vertebrates have been little studied compared to marine invertebrates. This project focuses on Chondrichthyes, which, together with other marine fish, appeared to have been relatively unaffected by the extinction, while most of their supporting ecosystem collapsed. This study explores the authenticity of extinction among chondrichthyans and possible explanations for the observed patterns, because extinction severities on the taxonomic and ecological levels may be decoupled or the quality of the fossil record may be variable. The presented analyses are based on a newly compiled database that supercedes older compilations. It is supplemented by material obtained from numerous localities globally, which includes newly described taxa. Hence, this study attempts to be the most up-to-date and comprehensive analysis of patterns and trends in chondrichthyan diversity and distribution that is currently available. The data demonstrate that, despite some variability in the Permian–Triassic chondrichthyan fossil record, the Lopingian record is shown to be of adequate completeness and, furthermore, range-through genus diversity is not significantly correlated with the number of taxonomic occurrences. Genus diversity declined from the mid-Guadalupian following an increasing extinction rate, which intensified throughout the Lopingian and thus supports a combined overall extinction as a result of the end-Guadalupian and Late Permian events. Furthermore, global distribution of chondrichthyan diversity shifted away from tropical regions and particularly the Boreal Sea gained in diversity, tracking extinction and recovery in marine benthic invertebrates in both time and space. No significant dependence of extinction on taxonomic structure or palaeoecological traits exists, which suggests proportional losses, except during the end-Smithian crisis. Also, a significant size decrease is absent among Permian/Triassic boundary-crossing taxa, suggesting selective loss of large-sized chondrichthyans rather than adaptive size decrease. Ultimately, the Hybodontiformes, Neoselachii, Xenacanthiformes and Holocephali are identified as the survivors, which possessed a varying combination of characteristics such as moderate body-size, adaptation to brackish/freshwater environments, benthic or generalist littoral (clutching) feeding behaviour, and a wide palaeogeographic range.

In recent years ideas about connectivity have become increasingly influential in theories pertaining to wildlife conservation. These ideas range from concerns with spatial habitat linkages or species' movements, to the forms of connection existing between 'people' and 'nature'. This thesis is concerned with how these various forms of connectivity are enacted in wildlife conservation through varied spatial practices. Following Mol (2002), I suggest that these modes of connectivity are enacted not separately but as a multiple. Indeed, through tracing how connectivity is enacted in a series of conservation situations relating to woodland mammals in England and Wales (red squirrels, pine martens, and wild/feral boar), I suggest that these multiple spatial practices of connectivity shape the biopolitical possibilities for living with non-human life. Since the connectivity multiple is composed, following Latour (2010) I further argue that it can be recomposed. Thus, I make the normative suggestion that contemporary trends in conservation policy (towards larger-scale action, process-based objectives, and neoliberal modes of governance) might be rethought and differently articulated through a conceptual and practical approach I term <strong>revitalizing conservation</strong>. This thesis thus makes several important contributions to geographic literatures. Following a widespread (re)affirmation of nonhuman agency in social science (e.g. Latour, 2005; Callon et al, 2009; Braun &amp; Whatmore, 2010), and particularly the agential capacities of animals (Wolch &amp; Emel, 1998; Philo &amp; Wilbert, 2000), it foregrounds the role of woodland mammals in enacting connectivity through developing the concept of animal mobilities. Furthermore, it engages with existing work tracing affirmative possibilities for conservation (bio)politics (Whatmore, 2002; Lulka, 2009; Hinchliffe et al, 2005; Hinchliffe, 2008; J.Lorimer, 2010, 2012, 2015), by illuminating the intersection of spatial practices of connectivity, and the potential these offer for alternative modes of 'living with' more-than-human lives.

Land areas being used unsustainably are depleted and/or degraded. To prevent this from happening and/or to reverse the effects, we need to restore these environments. However, not all restoration practices are equal, and some do not adhere to rigorous standards of sustainability. In this study, restoration guidelines and opinions from field experts were analysed from an SSD perspective. The focus of this thesis was limestone quarries in northern Europe due to quarries’ impacts to the socio-ecological system and the sensitivity of northern ecosystems. The results were divided into two sub-sections: FSSD comparison to guidelines, which included an SP analysis to principles in guidelines, and interviews. The conclusion was that the SSD approach could enhance these quarry restoration guidelines by incorporating the recommendations formulated from the results and discussion. One recommendation was having the eight SPs as overarching boundaries for success. Incorporating these recommendations would fill the sustainability gaps, aiding in the practitioner's ability to be strategic and have long-term success within sustainable limits.

Shellfish aquaculture is a developing industry along northeast Pacific coastlines and represents another potential stressor to already impacted nearshore ecosystems. The industry is particularly prominent in Baynes Sound, British Columbia (BC), Canada. The region hosts the operations which account for approximately 35% of all clams and 50% of all oysters produced in BC. Concurrently, it represents one of the most ecologically valuable areas in the northeast Pacific. In this study, I examined the interactions of benthic intertidal shellfish aquaculture with nearshore fish communities using abundance, biodiversity (species richness, diversity, and evenness), and functional diversity (Rao’s quadratic entropy and functional evenness) metrics. Also, I measured habitat complexity, as defined by a contour distance:linear distance ratio, at all fish sampling sites because it has often been identified as a driver of community variation. Fish abundance, biodiversity, and functional diversity did not vary between aquaculture and non-aquaculture sites. Additionally, habitat complexity, while on average was 1.2x greater at aquaculture beaches compared to non-aquaculture reference beaches, was not a strong driver of these indicators. Fish communities in Baynes Sound are relatively homogenous on a small scale and are highly functionally redundant, meaning that there is considerable overlap of species’ roles in the ecosystem. In summary, the presence of shellfish aquaculture in Baynes Sound is not associated with either a positive or negative response of fish communities. Furthermore, these communities are functionally redundant and therefore are likely resilient to ecosystem disturbances. / Graduate

When ovipositing, prey organisms avoid habitat patches containing predator cues because predators consume, and negatively affect the fitness of their prey. Richness of predator species often enhances the strength of consumptive predator effects, but little is known about how multiple predators combined affect prey non-consumptively. We quantified dipteran colonization in aquatic mesocosms in response to varied predator richness. Multiple predator species combined reduced oviposition by Culex mosquitoes, chironomid midges, and the general colonizing dipteran community more than predicted by the effects of the independent predator species. Previous research which quantifies effects of multiple predators on prey as prey abundance, but does not measure consumption by predators, may be underestimating or overestimating the strength of effect by assuming equal colonization. Our findings enhance understanding of the ways predators influence abundances and distributions of their prey, and yields insight into the ways predators may non-consumptively affect prey by changing prey behavior.

Fens are increasingly recognised as important habitats in terms of biodiversity, and this has been formalised in recent legislation (EC Habitats Directive, 92/43/EEC). The influence of groundwater and surface water inputs on the fen habitat increases its vulnerability to water pollution, particularly from nutrients. Despite the conservation importance and potential vulnerability of the habitat, fens have not been widely studied in Scotland, in terms of extent, location, sensitivity to increased nutrient inputs, or in comparison to similar European sites. This study found that fens were widespread throughout mainland Scotland, and that basin fens were the most commonly occurring fen type, representing 43% of the 355 sites assessed. A survey of 18 basin fens found that 72% were potentially vulnerable to elevated nutrient inputs, being surrounded by improved/modified land. Despite this, only four sites showed greater nutrient concentrations in sub-surface water samples or water inputs. There was, however, a significant amount of variation in hydrochemistry between the sites. Detailed studies further assessed spatial and temporal variations in hydrochemistry, and associated hydrologic regimes on two similar basin fens, one in an agricultural catchment, the other surrounded by unimproved grassland. Spatial patterning of vegetation was associated with both base-richness and nutrient concentrations of subsurface water, and the frequency of water inundation. General relationships between the six fen vegetation types and the observed hydrological and hydrochemical variation were presented.

La thèse s'intéresse à l'enregistrement des propriétés de la biodiversité dans les archives sédimentaires. Elle s'appuie sur l'analyse d'une faune contemporaine de milieu tropical, collectée dans le Lagon de Touho, Nouvelle-Calédonie lors de l'expédition Montrouzier en 1993. Les différences de diversité entre les assemblages de bivalves vivants et de coquilles mortes d'un même site sont quantifiées à l'aide de plusieurs descripteurs (richesse taxonomique, indice PIE d'eveness, courbes de raréfactions, indices de fidélité) et d'outils de classification (analyses Cluster, NMDS). Les associations d'espèces vivantes varient dans l'espace en fonction de paramètres environnementaux comme le type du substrat ou la profondeur. La composition des assemblages morts diffère des écosystèmes vivants, mais ils conservent globalement les informations environnementales. Les assemblages morts sont en général plus diversifiés que les communautés vivantes associées, à cause de l'accumulation de nombreuses espèces rares. Cet enrichissement s'explique par : 1) la préservation des coquilles autochtones, 2) l'apport de coquilles allochtones et 3) la condensation du temps. Des différences de fidélité entre les communautés biologiques et les assemblages de coquilles mortes apparaissent en fonction des environnements. Par exemple, les environnements à substrat induré sont associés à une mauvaise préservation des communautés vivantes, contrairement aux environnements profonds qui conservent bien les espèces autochtones mais accumulent beaucoup d'espèces allochtones. / The thesis explores how the properties of biodiversity are preserved in the sedimentary archives. Discussions are supported by the analysis of the modern tropical fauna of the Touho Lagoon (New Caledonia), collected during the Montrouzier expedition in 1993. The differences between live bivalve assemblages and dead shell assemblages are quantified with various indices (taxonomic richness, PIE index of evenness, rarefaction curves, fidelity indices) and classification tools (Cluster analyses, NMDS).Environmental parameters, such as the type of substrate or the water-depth, are responsible for variations among live species associations. The composition of dead shell assemblages differs from the living communities but environmental informations arepreserved. Generally, the dead shell assemblages are more diversified than live fauna of the same sites because of the accumulation of rare species. The higher diversity of dead shell assemblages can be explained by 1) the preservation of autochthonous bivalve shells, 2) the input of allochthonous shells and 3) the time-averaging. The fidelity of dead shell assemblages to the biological communities varies according to the environmental conditions. For example, dead shell assemblages found on hard substrate environments may be very different from the living communities. Allochthonous species tend to accumulate in deep outer shelf environments... Salinity, substrate or water-depth are main perturbation factors, as they imply loss or gain of taxa.The preservation of living communities varies according to the biological caracteristics, such as ecology, population structure or shells mineralogy.

This diploma thesis deals with legal regulation of creation and protection of Natura 2000 network. Natura 2000 is a system of protected areas created in Member States of the European Union which is aimed at preservation and potential renewal of natural habitats and rare and threatened species of wild fauna and flora. The objective of the creation of Natura 2000 network is to ensure the diversity of species and ecosystems, primarily the rare and threatened ones. The network is composed of the Special Protection Areas (SPAs) designated on the basis of the Birds Directive and of the Special Areas of Conservation (SAC) designated according to the Habitats Directive. The introductory chapter deals with historical development of the nature conservation on the Czech territory up to the present and as follows it gives an explanation of the term the Natura 2000 network. The chapter 2 is devoted to the most significant international conventions related to Natura 2000. The Bern Convention has even inspired some articles of the regulation included in the Directives. The chapter 3 is focused on the European legal regulation of nature and biodiversity protection. The nature conservation area comes under the EU environmental policy and it is related to other policies as well. The legal basis is contained in the...

The phylogeny of the turtle genus Pseudemys is poorly understood. In Virginia, many turtles have been found with indicator traits of both eastern river cooters (Pseudemys concinna concinna) and northern red bellied cooters (Pseudemys rubriventris). This study explores morphological evidence for hybridization between the two species across three riverine sites in east central Virginia. Museum voucher groups for each species were analyzed for relative shell height and plastron length. The shape of the plastral scutes and upper jaw were analyzed using landmark-based morphometric software. These metrics were compared with measurements taken from 188 field-caught Pseudemys specimens. Across phenotypic metrics, field specimens resembled northern red bellied cooters. Geometric morphometric analysis showed extreme variation. Thirteen field specimens exhibited indicator traits of both species. Because species boundaries do not appear to be well-resolved using accepted phenotypes and morphometrics, we suggest that additional research utilizing molecular methods and genetic analysis be conducted.