The decline of bumblebee (Bombus spp.) populations in the UK and worldwide has been well reported. It has been generally assumed that such declines result in the genetic impoverishment of some species, potentially leading to reduced fitness and increased extinction risk. This study tested the fundamental assumption linking population fragmentation with fitness, in a model system of two Bombus species native to the UK. Bombus monticola has declined significantly in range across the UK in recent years and occupies fragmented upland areas, while Bombus pratorum has remained abundant and widespread over many habitat types. The effects of genetic diversity on fitness have been addressed in wild Bombus species, but this is the first study to explicitly compare data from species of differing levels of population connectivity and hence test the assumptions of traditional population genetic theory. As genetic diversity has often been linked with immunocompetence, aspects of the innate immune response were quantified, together with parasite load. These empirical measures of fitness showed lower than expected variability between the two study species, and no evidence was found to support the theory of lower fitness in fragmented populations. However, the considerable variability between sample sites in both species for all parameters measured raised interesting questions as to the underlying evolutionary processes; it is postulated that B. monticola populations may maintain a higher than expected Ne, despite their fragmented distribution. This study also provided methodological developments. An alternative method for the quantification of wing wear as a proxy for age was proposed, which could be easily applied to other Bombus species and possibly adapted for use in other flying insects. In addition possible sources of error in AFLP analysis were highlighted which have not been adequately discussed in the current literature, namely the effects of sample storage. Given the utility of AFLPs for non-model species, this is an important avenue for future research, and would be applicable to studies in other systems. Overall, the data presented here emphasise the challenges of studying fitness in wild populations, and underline the requirement for research into the fundamental principles underlying many assumptions made by conservation genetic theory.

No description available.

Myers first identified the world’s 25 biodiversity hotspots and pioneered innovative ideas about the usefulness of biodiversity models for establishing long-term resource conservation strategies at global scales. Since Myers, most of the subsequent studies using hotspot science for biodiversity modeling have used large spatial scales like countries, provinces or states, and other biogeoraphic regions. The California Floristic Province continues to be one of the recognized global biodiversity hotspots. Our study site, San Luis Obispo County is within this hotspot and we created a map of plant biodiversity hotspots at the county scale using GIS technology. We wanted to determine the effectiveness and applicability of biodiversity hotspot mapping at this scale with anticipation that the map will serve as a new tool for establishing long-term resource conservation strategies in the County. Our plant biodiversity hotspot map is based on distribution data collected from herbarium specimens of San Luis Obispo County’s rare flora. These data were extracted from the Hoover Herbarium at Cal Poly and manually digitized into GIS. We built a model with GIS to identify, locate, and quantify the resultant hotspots from the data. The overall approach was successful at identifying and quantifying the attributes and geographic extents of plant biodiversity hotspots at the county scale. Our results are highly applicable for establishing local and regional plant conservation priorities at lower resolutions, which is frequently where land acquisition and reserve establishment occurs. We conclude that biodiversity hotspot modeling with GIS is an effective tool that can be applied to many other finer-scale biological inventories for conservation purposes.

No description available.

Comprendre les mécanismes d'assemblages des communautés est l'une des principales questions en écologie et biogéographie. Elle est également essentielle pour prédire les conséquences des changements globaux sur la distribution future de la biodiversité. Les communautés écologiques sont la résultante de facteurs interagissant à plusieurs échelles spatiales et temporelles. En outre, ces processus peuvent affecter différemment les composantes taxonomique, fonctionnelle et phylogénétique de la biodiversité. Nous étudions ici les processus écologiques qui structurent les communautés de poissons de récif, l'un des assemblages de vertébrés les plus diversifié sur Terre. Les facettes taxonomique et fonctionnelle de ces assemblages ont été étudiées au travers de plusieurs échelles spatiales. Nos objectifs sont (i) d'identifier les facteurs structurant les assemblages de poissons de récif à différentes échelles (du régional au local), (ii) d'évaluer dans quelles mesures les processus structurant les groupes taxonomiques et fonctionnels sont consistants entre eux et (iii) de comprendre la distribution de la rareté fonctionnelle dans les assemblages de poissons de récif. Deux bases de données ont été utilisées : (1) une base de données sur les caractéristiques fonctionnelles et les distributions globales de plus de 6000 espèces de poissons dans six régions biogéographiques ; (2) un ensemble de données comprenant les occurrences de 1 474 espèces de poissons sur 9 681 échantillons obtenus le long de transects (comptages visuels en scaphandre autonome) de 40m² à travers 252 sites dans plusieurs régions biogéographiques. Dans l'océan Atlantique, la structure taxonomique et fonctionnelle des communautés de poissons a une signature biogéographique, avec une différence marquée entre les espèces des récifs biogènes riches (dans les Caraïbes et composée des petites espèces) et les régions périphériques dominées par des espèces plus grandes. L'environnement joue également un rôle important dans la structuration des assemblages dans d'autres domaines biogéographiques. Alors que la composition taxonomique des communautés est principalement liée à l'isolement des récifs, la structure fonctionnelle est influencée par la disponibilité de l'habitat à l'échelle locale. Encore une fois, il y a une plus grande contribution des petites espèces dans les sites les plus riches alors que les grandes espèces dominent en périphérie, suite à la plus forte capacité de colonisation des grandes espèces. Les assemblages présentent des structures fonctionnels emboîtées. Plus précisément les sites pauvres en diversité fonctionnelle, ici mesurée en nombre d'entités fonctionnelles différentes, sont des sous-ensembles des sites riches. Cette structure résulte de l'interaction entre les capacités de dispersion/colonisation des espèces et/ou des besoins en ressources, ainsi que des gradients d'isolement et de surface. Malgré la présence de groupes fonctionnels essentiels et de redondance dans les assemblages de poissons, la majorité des espèces dans les communautés sont rares. De plus, les espèces rares occupent une large proportion de la gamme de traits fonctionnels et effectuent souvent des fonctions uniques. Selon les scénarios simulant la perte d'espèces rares (de 8 à plus de 200 espèces rares / moyenne : 78,2 ± 62), il y aurait une perte élevée - 80 % dans un seul site - de la diversité fonctionnelle. Nos résultats révèlent que les processus au sein d'un domaine biogéographique sont responsables d'une structuration taxonomique et fonctionnelle. De plus, le rôle essentiel de la capacité de colonisation de l'espèce met en évidence l'importance de la connectivité pour le maintien de la structure fonctionnelle des communautés de poissons de récif. Enfin, la contribution des espèces rares à la diversité fonctionnelle montre que ces taxons doivent être protégés afin de maintenir l'ensemble des fonctions et services des écosystèmes. / Understanding the mechanisms of community assembly is one of the main questions in ecology and biogeography, and is essential for predicting the implications of future biodiversity loss. It is known that an array of processes operating at different spatial and temporal scales interact to produce ecological communities. These processes may affect differently the multiple components of communities: the taxonomic, functional and phylogenetic components. Here we investigate the patterns and processes structuring one of the most diverse vertebrate assemblages on Earth: reef fishes. Reef fish assemblages were assessed across multiple spatial scales, under a taxonomic and functional perspective. Our main objectives included: (i) the identification of determinants of structure in reef fish assemblages across scales (regional to local); (ii) assessing to which extent the processes behind assemblage structures are consistent for taxonomic and functional groups; (iii) understanding the patterns of functional rarity in reef fish assemblages at a global scale. Two databases were utilized: (1) an extensive database on the functional traits and the global distributions of over 6,000 reef fish species across six marine biogeographic regions; (2) a dataset comprising the occurrences of 1,474 fish species over 9,681 underwater visual transects of 40m2 across 252 sites, also throughout the major biogeographic regions. Within the Atlantic Ocean, the taxonomic and functional structure of reef fish assemblages exhibit a biogeographic fingerprint, with a marked discrimination between species rich biogenic reefs – primarily in the Caribbean, where communities were dominated by small invertebrate feeders – and poorer peripheral regions dominated by larger species with more diverse diets. At the regional scale, both historical events and environmental characteristics (coral reefs vs. periphery) have played a role in structuring both components of assemblages. The role of environment features also holds for the structure of assemblages in other biogeographic realms (i.e. Indo-Pacific and Tropical Eastern Pacific). While the taxonomic composition of assemblages is mainly related to reef isolation, the functional structure is influenced by local habitat availability. Again, there is a greater contribution of small-bodied species in the most species-rich locations; and large-bodied species prevailing in peripheral assemblages, a pattern related to species' colonization capacity. Reef fish assemblages across most regions depicted significantly functional nested structures, attributed to functional redundancy – different species constitute a number of key functional entities. The nested structure results from the interaction between species' dispersal/colonization capabilities and/or resource requirements, with isolation and area gradients. Despite the existence of key functional groups and redundancy, the majority of species are rare (low abundance or occupancy). Also, rare species fulfil much of the range of functional traits within reef fish communities and often perform unique roles. Under scenarios of rare species loss (from 8 to over 200 rare species/ mean: 78.2±62) there would be high functional diversity erosion in the majority of reef fish communities, this level reaching up to 80% of functional diversity in one location. However the extent to which these functional groups actually contribute to ecosystem functioning is unknown. Our results reveal that within-realm processes, such as evolutionary histories, have shaped the taxonomic and functional structure of assemblages in each realm. Moreover, the key role of species' colonization capacity highlights the importance of connectivity to the maintenance of the functional structure across reef fish communities. Finally, the contribution of rare species to functional diversity indicates that protecting these taxa is essential to maintain ecosystem functioning and services in reef fish communities.

Le rôle des restrictions de vente sur l’évaluation de l’offre et l’intention d’achat reste controversé. La littérature marketing est divisée à ce sujet et met en avant différents cadres conceptuels et théories susceptibles d’expliquer les effets de ces restrictions. Face à ce manque d’unanimité dans la littérature et dans un contexte où la rentabilité des promotions de vente n’est pas établie, cette thèse vise une meilleure compréhension de l’impact des limites temporelles sur l’évaluation d’une offre promotionnelle de vente et l’intention d’achat du consommateur. Cette étude a été réalisée à l’aide d’une méthodologie mixte, basée sur une étude exploratoire, et une étude quantitative conduite selon la méthode des vignettes. Les résultats soulignent un comportement ambivalent des consommateurs face aux restrictions temporelles et mettent en évidence un rôle modérateur de la marque pouvant atténuer la perception des inconvénients dans le cadre d’une restriction temporelle de vente. / The role of the sales restrictions on the evaluation of the offer and the intention of purchase still stays controversial. The marketing literature is divided over the subject and sets up different conceptual frames and theories explaining the effects of these restrictions. Facing the lack of unanimity in literature, in a context where the rentability of sales promotions is not established, this thesis aims to a better comprehension of the impact of the temporal limits on the evaluation of a promotional sales offer and the intention of the consumer's purchase. This survey was made through a mixed methodology made by an exploratoring study lead by focus groups and by a quantitative study lead by the scanario method. The results of our explorating survey underline an ambivalent behaviour versus the temporal restriction of sales. Our empiric study reveals a moderating role of the brand able to limit the perception of the drawbacks in the space of the time restrictions of sales.

[Truncated abstract] In south-western Australia a rare plant community occurs on shallow soils overlaying massive ironstone rock. These 'ironstone communities' are open shrublands, which are subject to extremes in drought and solar radiation and support many rare and endemic species. The restricted distribution of many of these species may be related to their high degree of specialisation to this harsh habitat and their inability to respond plastically to different environmental conditions. Indeed, earlier work has shown that ironstone Hakea species (Proteaceae) have a specialist root-system morphology investing mainly in deep roots, thereby increasing their chance of accessing cracks in the rock surface and obtaining water before the onset of summer drought. In this thesis I further examine aspects of specialisation and its possible consequences for species rarity using two ironstone Hakea species and comparing them with two of their widely distributed congeners. In the first experiment (Chapter 2) I explore inherent drought tolerance, independent of root-system morphology, as a further specialisation to the ironstone environment. All species were grown in sand in pots in a glasshouse for 7 months and then droughted for 5 weeks. There was no evidence that the ironstone species had a greater inherent drought tolerance than their common congeners. During drought all species maintained leaf water content of mature leaves by reducing stomatal conductance and osmotically adjusting, though ironstone species tended to OA (osmotic adjustment) more than common species. ... This suboptimal investment of resources may result in a lower competitive ability in shadier environments, and thus could partially explain their restricted distribution. In Chapter 4, I investigated the plasticity of root traits in response to levels of phosphorus supply. South-western Australian soils are phosphorus impoverished and phosphorus is well known to elicit plastic responses in root allocation and architecture. Ironstone species showed less plasticity in total root length, producing similar root length across P treatments, while common species showed an increase in root length with increasing [P]. Other root characteristics were similarly plastic in response to P treatment between species. However, when supplied with increasing [P], ironstone species invested an increasing proportion of roots in the bottom of pots while common species invested more in the top. This differential response in root allocation in response to P may reflect a fundamental trade-off between nutrient and water acquisition, with the ironstone species mainly foraging for water and investing in deeper roots, while the common species invest more in superficial roots to obtain nutrients. In conclusion, the rarity and restricted distribution of the ironstone Hakea species may be related to their specialist root-system morphology as well as a lowered phenotypic plasticity of functional traits. A reduction in plasticity may reduce their competitive ability outside their ironstone habitats, and thus contribute to the restricted distribution of these species. This may also be the case for other rock-outcrop endemics and more generally, for other rare plant species restricted to particular habitats where a lowered phenotypic plasticity in traits relevant to their particular habitat may contribute to their restricted distribution.

The plants of San Quintín (Baja California, Mexico) were documented through intensive fieldwork and the collection of herbarium specimens to create a checklist of species. This region is home to a diverse flora with high levels of local endemism and many rare plants. The flora documented in this study was compared to historical records from the region and shows the impact of agriculture and urbanization on the plants, including several extirpated species. A study of the perennial vegetation using a 1 km grid provides species distribution data for 140 native species, which were assessed to highlight areas of significant species richness for native, rare, and endemic taxa. Several non-native plants were also mapped to provide baseline data. Areas of conservation priority for the flora of Greater San Quintín are discussed in light of these combined findings.

Japan is one of the world’s 34 biodiversity hotspots, according to Conservation International (CI). The methods used by various organisations to define priorities differ, however, and all have weaknesses when trying to identify hotspots at finer resolutions. The goal of this thesis is to investigate how biodiversity hotspots in Japan could be revealed and mapped in order to encapsulate conservation elements of biodiversity in practical ways and at various scales. Bioquality is a term that emphasises the concentration within a community of elements of biodiversity with high conservation value. It evaluates the global rarity and taxonomic distinctiveness of plant species or infra-specific taxa using four Star categories. At a plant community level, the Genetic Heat Index (GHI), which is a standardised global range size rarity score, is calculated using weighted Star statuses of species in the community. Bioquality hotspots are assessed here for the first time for the flora and vegetation in Japan – and for temperate Asia – by categorising the Japanese flora into Stars and by applying GHI to survey data and literature-based sources. Keys to Stars are developed for the Japanese flora, with adjustments for variability in species geographic range size information and for taxonomic relatedness. A Flora of Japan (FOJ) database was compiled as a BRAHMS database, containing 8,262 accepted names (30,656 taxon names in total, including synonyms) in 258 families – the first full database of Japanese vascular plants. A total of 7,145 taxa are assigned Stars; from the rarest to the widespread class, there are 884 Black, 756 Gold, 833 Blue, and 4,672 Green Star taxa, confirming that Japan as a whole contains a high proportion of globally rare taxa (23% taxa in Black or Gold). A protocol for calibrating the weight of Stars based on species geographic range is developed based on fine-resolution distribution maps within Japan and coarse–resolution Taxonomic Database Working Group (TDWG) code information. The protocol optimises calculation for temperate regions. The first ever bioquality hotspot maps of Japan are produced using two independent data sources on species distribution at national level: 1) 50 botanical prefectures using 4,830 species from the FOJ database; 2) 1,418 Horikawa ‘geoquadrats’ (0.1° latitude by 0.15° longitude grid) maps covering 829 species. The Ryukyu Islands and Ogasawara Islands are identified as bioquality hotspots, and high mountain ranges in mainland Japan are predicted to contain areas potentially high in GHI; the spatial patterns of GHI are generally concordant between maps of different resolutions. These findings highlight that bioquality assessment can be applied meaningfully at various spatial resolutions. Using field sampling data and existing literature, three study sites are further investigated on a local level: 1) the satochi-satoyama landscape, the current national priority area for biodiversity conservation; 2) various vegetation types of Okinawa-jima Island, the Ryukyu Islands; and 3) the Utaki sacred groves within the predicted hotspot of the Ryukyu Islands. The Ryukyu Islands are confirmed to contain bioquality hotspots within many individual sites, while there was generally low GHI across the satochi-satoyama landscape. The field study outcomes, together with a gap analysis of the existing coverage of protected areas, highlight three important points that are directly relevant to national biodiversity conservation planning: 1) the Ryukyu Islands urgently need newly designated protected areas; 2) the satochi-satoyama landscape conservation should redirect its focus on cultural benefits to the public; 3) the existing protected areas, particularly on mountain areas, need re-evaluation in terms of upgrading their status in light of the bioquality assessment.

The development of genetic tools to study populations at the molecular level has been one of the most important contributions to understand demographic processes in wild populations of conservation concern. Habitat loss and habitat fragmentation are the main factors causing declines of birds populations, as in the case of the Worthen’s sparrow (Spizella wortheni), a Mexican endemic Emberizid restricted to scrub and grassland habitats in northeastern Mexico. Here, I present the first molecular tools developed specifically for the study of S. wortheni populations. Genetic analyses of seven remnant populations of S. wortheni showed that no genetic impoverishment is present. This unexpected result may be caused by the nomadic life style of S. wortheni, which makes it tolerant to habitat modification. The high levels of inbreeding I found can be attributed to the tendency of S. wortheni to move in gregarious groups, since non-random mating might be present. My analyses based on the study of DNA segments from five mitochondrial genes support the hypotheses that S. wortheni and S. pusilla (Field Sparrow), as well as S. breweri (Brewer’s Sparrow) and S. passerina (Chipping Sparrow) are sister taxa. A phylogenetic network analysis showed that conflicting relationships among Spizella species might be caused by possible hybridization events between ancestors of extant taxa. Based on the study of the phylogenetic community structure, patterns of phylogenetic attraction and repulsion, and on the estimation of marginality, specialization and niche overlap among species, I investigated the possible causes of rarity in S. wortheni. The phylogenetic community structure analysis suggested that Spizella species are clustered across vegetation communities. Assuming phylogenetically conserved ecological traits, the phylogenetically clumped distribution may indicate habitat filtering among Spizella species. Additionally, behavioral traits such as flocking in mixed-species flocks might contribute to explain the pattern of community structure I found, and suggest that the rarity of S. wortheni is not a matter of interspecific competition. According to the phylogeny, evolutionary age was also discarded as a cause of rarity of this species. Compared with its congenerics, S. wortheni is the most specialized of all Spizella species. A potential evolutionary change of S. wortheni behavior that results in niche specialization is more likely to be the cause of its rarity.