Global biodiversity is under threat from multiple fronts. The Millennium Ecosystem Assessment predicts that climate change (CC) will be the “dominant direct driver of biodiversity loss” by the end of the 21st century. This project studies the impact of CC on the distribution and conservation status of antelopes found in Africa. Africa is an area of high climate variability and high vulnerability to CC, and most of the world’s antelope species are native to the continent. Various threats are already causing the decline in 63% of antelope species with 26% being classified as threatened. Antelopes are a speciose and biologically diverse group and therefore provide an ideal opportunity to reveal more general patterns of the effect of CC across taxa. To assess the impact of climate change on Africa’s antelopes I use species distribution models (SDMs), based on climatic variables, to produce ensemble predictions of species distributions for 2080. Using the SDMs I also establish links between biological traits and the optimal climatic conditions for species. The ensemble predictions incorporate three climate models for three climate scenarios, and I predict the future distributions using three approaches. The first is a pessimistic representation of species’ distributions in a future where they are unable to disperse from their current range to track CC. The second, optimistic approach, permits species to disperse at a given rate based on body mass. Finally, the envelope approach presents a comparison of suitable climatic conditions, which are connected to the existing distribution, between now and the end of the century (i.e. not restricted by current distribution or dispersal). The results indicate that 81-85% of species (59-62 of 73) will exhibit a contraction in range based on suitable climatic conditions, and that the average contraction of those species is 39.4-50.1%. Up to six of 73 species are predicted to be without any climatically suitable areas in 2080 depending on the modelling and forecasting approach taken. Worryingly, there is also a disproportionate reduction in the predicted distribution of threatened antelope, whereas species with broader climatic niche and a preference for warmer temperatures typically perform better. Using Marxan conservation planning software, I produce protected area network solutions that protect Africa’s antelopes based on their predicted distributions in 2080. High and low protection options are presented which require 8.7 and 8.1% respectively of Africa’s land mass in order to protect Africa’s antelopes. These solutions, that are based around the existing IUCN protected area network (categories I-VI), reveal key new areas are required in Somalia, while expansion of existing protected areas (PAs) are required continent-wide, particularly in Liberia, Cameroon, Kenya, Tanzania, and the Central African Republic. I also find that the contribution of community led PAs, and other non-IUCN PAs, to these solutions is currently limited, but in some areas they play an important role in bridging gaps between existing IUCN PAs. Finally, 14 species are either identified to qualify as threatened due to climate change based on IUCN Red List criteria, or can be considered threatened due to having no protected area coverage within their predicted range in 2080. Based on predicted species distributions under the A1B climate scenario, the hirola (Beatragus hunteri) and Aders’ duiker (Cephalophus adersi) have no suitable climatic conditions within, or connected to, their existing range in 2080. However, for all species, climatically suitable conditions are present in Africa in the future, and protected areas are found within those regions. For the species most at risk I provide recommendations for translocation options taking into account the potential for interspecific competition by assessing the number of novel antelope species and interspecific niche overlap in the climatically suitable areas.

Freshwater systems are generally found to be sources of CO2 to the atmosphere and evasion of CO2 from fluvial systems is now recognised to be a significant component of the global carbon cycle. However detailed understanding of fluvial carbon dynamics and controls on the system is lacking and global coverage of published data is sparse, but thorough understanding across a broad range of locations is crucial if global carbon budgets are to be refined. This research addresses this lack of understanding by investigating the magnitude, controls and sources of CO2 efflux across five catchments with different catchment characteristics, global locations and climate-change sensitivities. In doing so new understanding is used to explore a novel method for large-scale upscaling of CO2 efflux, time series reconstruction of the source and magnitude of CO2 efflux and incorporation of an Arctic region into the global fluvial carbon budget. The magnitude of and controls on CO2 efflux are not well understood, although it has been suggested that increased flow velocity and turbulence can enhance CO2 efflux rates. This research uses direct and contemporaneous measurements of CO2 efflux (range: -3.53 to 107 μmol CO2 m−2 s−1), flow hydraulics (e.g. mean velocity range: 0.03 to 1.39 m s-1; shear Reynolds number range: 350 to 174000), and water chemistry (e.g. pCO2 range: 388 to 4660 ppm), at sites in three UK catchments to assess whether flow intensity (a term which is used to describe one or more measures of flow strength and turbulence) is a primary control on CO2 efflux. These field sites have been chosen as they have contrasting size and land use: Drumtee Water (DW), 5.7 km2 and rural, the River Kelvin (RK), 335 km2 and urban, and the River Etive (RE), remote and snow-melt influenced. At the more soil-dominated sites DW and RK, a strong positive logarithmic relationship exists between CO2 efflux and measures of flow intensity (e.g. shear Reynolds number, overall R2 = 0.69), but this relationship is strengthened by including pCO2 (overall R2 = 0.72). Flow intensity may have a key influence on CO2 influx, although data are limited. A method using visual classification of flow intensity shows promise for supporting large-scale upscaling of fluvial CO2 efflux, if classification of water surface state can be standardised. Movement of dissolved inorganic carbon (DIC) through the hydrological cycle is an important component of global carbon budgets, and how they may respond to changing climatic conditions. However uncertainty remains about the hydrological and biogeochemical controls on DIC transmission through a catchment. Using contemporaneous measurements of DIC concentration ([DIC]) and stable carbon isotope composition of the DIC pool (δ13CDIC), fluvial DIC at more soil dominated sites, DW and RK, is found to vary considerably in response to changes in catchment hydrology. At low flow groundwater dominates, and has similar composition in both systems ([DIC]: 1.5 mmol L-1 DW, 2.0 mmol L-1 RK; δ13CDIC: -9 ‰ DW and RK) indicating a common hydrogeological inheritance in DIC, that is comparable to that of other temperate and tropical locations. Differences in composition at high flow ([DIC]: 0.1 mmol L-1 DW, 1.0 mmol L-1 RK; δ13CDIC: -23 ‰ DW, -14 ‰ RK) reflect catchment land use, and a lower contribution of soil water to the DIC pool in the more urban catchment (RK). Measured diel cycles in DIC pool composition at DW indicate biological processes modify the pool, and time series reconstructions of pool composition and CO2 efflux at DW reveal seasonal- and flow-related patterns in this biological activity. Time series reconstructions also reveal that at DW terrestrial-aquatic-atmospheric carbon cycling is rapid during event flows, with large amounts of CO2, of soil-origin, effluxed to the atmosphere in relatively short periods of time. Conversely, at low flows, CO2 efflux is of smaller magnitude and primarily fuelled by groundwater, and terrestrial-aquatic-atmospheric carbon cycling is slower. The reconstructions allow for inter-year comparisons which are useful in assessing for behaviours in CO2 source and feedback that might be typical under climate change-induced changes in hydrology (e.g. wetter winters, drier summers, more frequent large flow events). Global ice melt and permafrost thaw are increasing due to climate change, effects of melting ice and thawing permafrost on the global carbon cycle, and carbon cycling dynamics of the melt/thaw waters are not well understood. Data from the River Etive has few similarities to that of DW and RK and indicates that snow- and ice- dominated systems may behave very differently to more soil-dominated systems in terms of magnitude and controls on efflux and sources and mixing of the DIC pool. This is confirmed by data collected from the melt/thaw waters of two cryospheric systems in Greenland: a Greenland Ice Sheet (GrIS) drainage river (Akuliarusiarsuup Kuua River, or AR) and the local permafrost-landscape surface-drainage systems (PLST). CO2 efflux appears independent of flow controls in both systems, and instead seems to be pCO2 limited (average pCO2: 115 ppm AR, 596 ppm PLST), with spatial variation in AR (efflux decreases downstream) and temporal variation in PLST (efflux decreases with melt season progression). The frequent occurrence of CO2 influx (measured in 64% and 14% of cases in AR and PLST respectively), which has rarely been reported from other rivers globally, reveals that Arctic fluvial systems can periodically act as net sinks of CO2 and this should be incorporated into global carbon budgets. The occurrence of CO2 influx, and dominance of air-water CO2 exchange in these low pCO2 systems, is reflected in the DIC pool composition which is 13C-enriched and approaches isotopic equilibrium with the atmosphere (~0 ‰), and indicates that soil and ground water contributes little to the DIC pool under frozen ground conditions. Radiocarbon analysis gives further insight into the source of carbon in these systems, revealing that the GrIS is releasing old DOC (~5200 to 6600 yrs BP) upon melting, which is considered to be highly biolabile and may prime bacterial activity and feedback to climate change, and meltwaters are returning old carbon (800 to 960 yrs BP) to the atmosphere via CO2 efflux. Thus it appears that climate change (via melting ice sheets) may be a driver of the age of atmospheric carbon composition. The effluxed CO2 being less old than the DOC indicates the source of CO2 efflux is a mixed pool of respired/UV-oxidised old DOC and modern atmospheric CO2 from drawdown. In contrast to GrIS meltwaters, and the permafrost of other global locations (e.g. the Siberian Yedoma deposits), the permafrost landscape of the Kangerlussuaq region of Greenland is cycling modern carbon and appears not to be degrading, as old carbon is not found in, or degassed from, the fluvial systems. In summary this research contributes to a greater understanding of fluvial carbon dynamics and the processes controlling the return of CO2 to the atmosphere via efflux, across an array of catchment types, sizes, land uses and global locations, and makes contributions of novel data to a number of areas of fluvial carbon cycling research where there are scarcities. Marked differences in the fluvial carbon cycling dynamics of cryospheric and snow-melt dominated systems compared to soil-dominated terrestrial systems are uncovered, novel upscaling attempts made using new findings of the research, and a number of exciting new research directions and opportunities that could enhance the findings of this work are identified. Overall, this research takes steps towards a greater understanding of fluvial carbon cycling dynamics on a global scale and improved projections of the likely response of fluvial systems to climate change, ultimately aiding the community to be more prepared for what our shifting climate will bring.

Calluna-dominated habitats, including dry heaths and peat bogs, provide important ecosystem services such as biodiversity, soil carbon stores and water supply. Climate change projections estimate drier conditions throughout their range, which could lead to increased wildfire activity. Such altered fire regime could induce a fundamental change to the ecology of Calluna moorlands and increase carbon emissions from their carbon-rich soils. The aim of this research was to understand how ecosystem response varies in relation to increased fire severity in Calluna heathlands and peat bogs. I completed experimental fires at two sites in Scotland, a dry heath and a raised bog, where I manipulated pre-fire fuel structure and fuel moisture content to achieve a gradient of fire severity and investigated the subsequent effect on post-fire vegetation regeneration and soil carbon dynamics. I found that drought increased fire severity in terms of ground fuel consumption and soil heating through increased flammability of the moss and litter layer. Substantially higher fire-induced ground heating was recorded when this layer ignited. When consumption of the moss and litter layer was extensive, post-fire soil thermal dynamics were altered and diurnal and seasonal thermal variation was higher, resulting in warmer soils that may lead to higher soil carbon emissions. Fire effects (ground fuel consumption, ground heating, changes in post-fire soil thermal dynamics) were much stronger at the dry heath than at the raised bog, likely due to ecohydrological differences between sites, i.e. thicker moss layer and deeper, wetter soil at the raised bog. For example, average fire-induced maximum temperatures at the soil surface at the dry heath increased from 31 degree C to 189 C due to drought, but at the raised bog they increased from 10 C to 15 C. Post-fire vegetation community composition varied in relation to the gradient of fire severity at the dry heath. Higher fire severity increased abundance of dominant ericoid species (Calluna vulgaris, Erica cinerea and Erica tetralix ) through improved substrate conditions (consumption of the moss and litter layer leading to bare soil), despite the fact that higher fire-induced soil heating hindered their regeneration. Short-term soil carbon emissions increased after burning due to a greater reduction in photosynthesis than in ecosystem respiration. Methane fluxes were negligible at the dry heath, but increased after burning at the raised bog, especially in warmer conditions. Generally, higher fire severity had little effect on soil carbon dynamics (ecosystem respiration, net ecosystem exhange, methane flux and dissolved organic carbon concentration), but higher autumn emission after higher fire severity at the dry heath and the important control of plant functional type cover suggest differences may become apparent in the longer term. This research advances our understanding of how an altered fire regime with higher fire severity could alter ecosystem functioning in Calluna moorlands and impact on its conservation value and belowground carbon stores. The work presented here can be useful to managers using burning as a land management tool, or who need to plan for wildfire occurrence in these fire-prone habitats, to inform strategies to accomplish a range of objectives, including conservation, protection of carbon stores and recreation, and to researchers interested in environmental change in Calluna moorlands. This research was funded by the University of Glasgow with support from the Centre for Ecology and Hydrology, the Ohio State University and Glen Tanar Estate.

No description available.

The foliar uptake by wheat of the wild oat herbicide flampropmethyl has been studied following application of ul droplets of an aqueous solution. The results show that over the time required for the drop to dry the compound does not partition into the surface waxes and crystallises as an external deposit. This deposit is stable to volatilization and photochemical and biochemical degradation, and is depleted by foliar penetration. Adsorbtion by the leaf surface wax is initially rapid and thereafter occurs at a relatively constant rate until the almost complete exhaustion of the surface deposit. Penetration of the epicuticular wax layer generally proceeds at a slower rate than does adsorption of the surface deposit and the herbicide is accumulated in the wax layer. The compound is lost from the epicuticular waxes only slowly to the leaf tissues. Movement within the leaf tissues away from the area of uptake is predominantly acropetal to the leaf tip and it is presumed that the compound moves with the transpiration stream. A similar fate befalls the compound when aqueous solutions of flamprop-methyl are applied as ul droplets to barley or wild oat, no evidence of selectivity between wheat, barley and wild oat as a consequence of preferential uptake was found. Foliar uptake of flamprop-methyl is shown to depend on the amount of compound applied to un1 t area of leaf surface and to increase as the amount applied is increased or as the area to which application is made is increased. These trends are discussed in terms of compartmental model of foliar uptake. Foliar uptake of flamprop-methyl is also shown to be slightly influenced by environmental factors; in an environment in which maximum daily temperatures exceeded 35 o C penetration was especially rapid and tended to completion within 24 hours. The surface properties of aqueous solutions of selected polyoxyethylene non-ionic surfactants have been studied prior to investigating the effect of these compounds on the foliar uptake by cereals of flamprop-methyl. Two types of non-ionic surfactant were included in this study, the alkylphenol ethoxylates as exemplified by the Triton X products (ex Rohn and Haas) and alcohol ethoxylates as exemplified by the Brij products (ex Atlas Chemical Industries). Products from both sources were analysed using instrumental and separational methods; the results of these analyses supported the manufacturers description of the compounds. Surface and interfacial tensions of aqueous solutions of the surfactants were determined at various concentrations. Maximum"reduction of surface tension in the alkylphenol ethoxylate solutions was found with Triton X-35 and Triton X-45. Maximum reduction of surface tension in the alcohol ethoxylate solutions was found with the tetraoxyethylene dodecyl ether (Brij 30) and was reduced with increasing oxyethylene content with anyone hydrophobe. At constant oxyethylene content it was shown that surface activ1 ty was dependent on the nature of the hydrophobe. Critical micelle concentrations were determined from plots of surface tension vs concentration for alkylphenol and alcohol ethoxylates. The spreading and wetting properties of aqueous solutions of alkylphenol ethoxylates were investigated by the Draves test and in terms of calculated spreading coefficients. The foliar uptake by wheat of ethoxy1ated non-ionic surface active agents has been studied following topical application of aqueous solutions. The permeability of the cereal leaf to these compounds has been demonstrated. the rate of uptake was shown to depend on the mean oxyethy1ene content of the surfactant, decreasing as the oxyethy1ene content was increased within the Triton X series of compounds. In quali tati ve terms the trend in uptake was paralleled by changes in both partition coefficient and (estimated) diffusion coefficient. The distribution of oligomers within anyone surfactant was apparently retained during transcuticular movement. Movement of the surfactant across the epicuticular waxes resulted in an accumulation of the penetrant in the tissues underlying the site of application. Movement of the surfactant in treated leaves was acropetal. The foliar uptake of f1amprop-methy1 by wheat has been studied following topical application of the herbicide formulated in aqueous surfactant solutions. Non-ionic ethoxylated surfactants have been found to markedly enhance transcuticular movement of the herbicide but do not promote transport of the compound wi thin treated leaves. The extent to which uptake was enhanced was largely influenced by the concentration of the formulation with respect to the surfactant, was much less dependant on either hydrophobe or hydrophile structure and was apparently independant, within experimental limits, of the herbicide concentration. Optimum surfactant concentrat1ons were between 100 and 1000 ppm. Correlation between penetration enhancement and the surface properties of the formulations was non-existent. The effect of the surfactant on penetration is discussed in terms of a surfactant/lipid interaction which facilitated diffusion of the herbicide. At high surfactant concentrations a variety of responses were identified ranging from varying degrees of enhancement through to an inhibition of transcuticular movement: these responses were shown to correlate with the resistance to uptake afforded by a persistent surfactant residue on the leaf surface.

A breeding population of Redshanks was studied by trapping adults at the nest and individually marking them, over a period of nine years, on part of the extensive Ribble saltmarshes. Other aspects of breeding biology were investigated over three years. The capture-recapture analysis of the breeding adults revealed an overall annual survival rate, of both sexes, of 0.77, and a population of approximately 200 pairs in 1.04km? Mate fidelity was very high, with 71% of surviving pairs remaining faithful. Nest site fidelity was extremely strong for faithful pairs and males with new mates, but significantly weaker for females with new mates. A lower nest site fidelity of young birds was regarded as a major contributing factor to their lower recapture rates. The timing of both the onset and ending of the breeding seasons varied greatly, and was determined mainly by the rainfall. High rainfall delayed onset and hastened ending of breeding. Mithin a breeding season the older birds bred throughout, while the young ones were mostly not able to breed early. The substantial losses of nests due to cattle grazing on the marsh (45%) could easily be controlled by preventing the access of cattle to the main breeding area until after the end of the nesting season. Nest predation was rare (less than 4%) in most years, but increased in a year of short vegetation (to 25%). The production of pulli was estimated under varying environmental influences and ranged from 0.73 to 2.28 pulli. pair": The variation of egg size within the population was investigated and the significant influences of laying order (within a clutch) and maternal size demonstrated. Pullus size at hatching was positively correlated with egg size and also with maternal size. The growth and development of pulli were described for weight, bill length, tarsus length and postnatal moult. For three days after hatching the weight remained below the hatching value and then rapidly increased, whereas the bill and tarsus showed a linear increase in length A tentative model of the population dynamics was produced, despite the lack of good estimates of pre- and post-fledging mortality. This model indicated a high pre-fledging mortality of 0.67 and also further highlighted the impact on the population of cattle grazing during the nesting season.

This study builds on a previous study that demonstrates the existence of deep mitochondrial lineages in the gecko Tarentola boettgeri within Gran Canaria (Gubitz et al. 2005). Here, I identified and analyzed the area where the two most divergent mitochondrial •lineages meet. The primary aim was to examine how geographical structuring of mtDNA has been maintained after secondary contact. MtDNA analyses used a 608 basepair fragment of the cytochrome b (cyt b) gene from 389 individuals sampled from 14 populations along a 32 km southeast (SE) transect across Gran Canaria. It revealed a low degree of mtDNA admixture and negligible gene flow across the contact zone. This led to the hypothesis that reproductive barriers may have formed between populations from different mtDNA lineages. Analyses of seven body dimension and scalation characters revealed that spatial patterns of morphological changes were not associated with the transition in mtDNA lineage frequency across the transect. This contrasted with another lizard species on the same island, Chalcides sexlineatus, in which phylogeography and morphology are highly correlated. This study identified ten unique microsatellite markers in T. boettgeri. Like morphology, analyses of these microsatellites did not reveal a pronounced spatial pattern of differentiation in the nuclear genome. These results appear to reject the hypothesis of a physical or genetic barrier to reproduction. Studies of micro satellites also suggested that T. boettgeri is a low dispersal species and this might explain the persistence of mtDNA contact zone. However, evidence of concordant spatial patterns between divergence in the nuclear genome and morphology was detected. The discordant spatial patterns of mitochondrial and nuclear genotype frequencies do not appear to be explained by sex-biased gene flow, and are difficult to understand because of expected interactions between the two genomes. Thus, further investigation is suggested to allow clarification of the causes of mito-nuclear discordance in T. boettgeri.

Field isolates of Botrytis cinerea Pers. from tomato crops gave rise to two distinct morphological types after successive single spore isolations; type 1 (T1) characterised by regular, rapidly growing mycelium and type 2 (T2) characterised by sparse, often distorted, slow growing mycelium. The frequency with which isolates produced these morphological types varied considerably. The reaction to benomyl of both types obtained remained the same as that of the parent isolate through successive single spore isolations on fungicide free agar over 10 generations. Benomyl tolerant field isolates could not be distinguished from sensitive isolates on the basis of colony morphology. Examination of 188 isolates of B. cinerea collected from 10 different tomato crops showed that sensitive isolates tended to be more pathogenic to detached tomato cotyledons and grew faster in vitro than tolerant isolates. In vitro and in vivo studies revealed no difference in the competitive ability of benomyl tolerant and sensitive isolates in mixed culture. In a study of 17 Lancashire tomato crops all were found to contain benomyl tolerant strains of B. cinerea although in some cases benzimidazole fungicides had not been used on the nursery for up to three years. Examination of B. cinerea in tomato crops suggested that the majority of stem lesions arose from infected leaf scars and were non-aggressive. Side shoot stumps or scars were also liable to infection and the resulting lesions were more likely to become aggressive than lesions at leaf scars. Conidia were considered to be the major source of inoculum although lesions at leaf scars could take up to 61 days to develop after deleafing. This delay was attributed to latent infection. Artificial infection of the petiole with B. cinerea prior to deleafing greatly reduced the susceptibility of the resulting leaf scar to subsequent attack by B. cinerea. Extracts from infected stems were shown to delay the germination of B. cinerea conidia when compared to extracts from healthy stems. This inhibition of germination was attributed to a resistance factor (RF) produced by the fungus or host in response to infection.

With over 200 pools, lakes and rivers supporting over 70 species of endemic flora and fauna, the Cuatro Cienegas Basin, Coahuila, NE Mexico is an extremely important and extensively studied area in terms of conservation. The palaeoenvironment, however, is relatively understudied with only two reconstructions published to date - Meyer [1973] and Minckley and Jackson [2008]. This project has analysed a 15 m carbonate sediment core for multi-proxy palaeoenvironmental information and combined this with stable isotope, modern hydrological and geoarchaeological information in the Cuatro Cienegas Basin.

No description available.