• Paternity analysis of wild-caught females shows that sperm package size and placement influence fertilization success in the bushcricket Pholidoptera griseoaptera

      Parker, Darren James; Zaborowska, Julia; Ritchie, Michael Gordon; Vahed, Karim; University of Lausanne; University of St Andrews; University of Derby; Centre for Biological Diversity; University of St Andrews; St Andrews KY16 9TH UK; Centre for Biological Diversity; University of St Andrews; St Andrews KY16 9TH UK; Centre for Biological Diversity; University of St Andrews; St Andrews KY16 9TH UK; et al. (Wiley, 2017-04-07)
      In species where females store sperm, males may try to influence paternity by the strategic placement of sperm within the female’s sperm storage organ. Sperm may be mixed or layered in storage organs and this can influence sperm use beyond a ‘fair raffle’. In some insects, sperm from different matings is packaged into discrete packets (spermatodoses) which retain their integrity in the female’s sperm storage organ (spermatheca), but little is known about how these may influence patterns of sperm use under natural mating conditions in wild populations. We examined the effect of the size and position of spermatodoses within the spermatheca and number of competing ejaculates on sperm use in female Dark bushcrickets (Pholidoptera griseoaptera) that had mated under unmanipulated field conditions. Females were collected near the end of the mating season and seven hypervariable microsatellite loci were used to assign paternity of eggs laid in the laboratory. Females contained a median of 3 spermatodoses (range 1-6) and only 6 of the 36 females contained more than one spermatodose of the same genotype. Both the size and relative placement of the spermatodoses within the spermatheca had a significant effect on paternity, with a bias against smaller spermatodoses and those further from the single entrance/exit of the spermatheca. A higher number of competing males reduced the chances of siring offspring for each male. Hence both spermatodose size and relative placement in the spermatheca influence paternity.
    • Paternity and kinship patterns in polyandrous moustached tamarins (Saguinus mystax)

      Huck, Maren; Löttker, Petra; Böhle, Uta-Regina; Heymann, Eckhard W.; Abteilung Soziobiologie, Deutsches Primatenzentrum, Göttingen, Germany; Abteilung für Verhaltensforschung, Universität Bielefeld, Germany; Institut für Neuro- & Verhaltensbiologie, Abt. Verhaltensbiologie, Westfälische Wilhelms-Universität Münster, Germany; Arbeitsgruppe Primatengenetik, Deutsches Primatenzentrum (DPZ), Göttingen, Germany (2005)
      We studied patterns of genetic relatedness and paternity in moustached tamarins, small Neotropical primates living in groups of 1–4 adult males and 1–4 adult females. Generally only one female per group breeds, mating with more than one male. Twin birth are the norm. In order to examine the genetic consequences of this mating pattern, DNA was extracted from fecal samples collected from two principal and six neighboring groups. DNA was characterized at twelve microsatellite loci (average: seven alleles/locus). We addressed the following questions: Do all adult males have mating access to the reproductive female of the group? How is paternity distributed across males in a group? Can polyandrous mating lead to multiple paternity? Are nonparental animals more closely related to the breeders than to the population mean? And, are mating partners unrelated? Breeding females mated with all nonrelated males. In at least one group the father of the older offspring did not sire the youngest infant although he was still resident in the group. We also found evidence for multiple paternity in a supposed twin pair. Yet, within each group the majority (67–100%) of infants had the same father, suggesting reproductive skew. Relatedness within groups was generally high (average R 0.31), although both nonrelated males and females occurred, i.e., immigrations of both sexes are possible. Mating partners were never found to be related, hence inbreeding seems to be uncommon. The results suggest that while the social mating system is polyandry, paternity is often monopolized by a single male per group.
    • Peanut exposure during pregnancy, breastfeeding and complementary feeding: perceptions of practices in four countries

      Boulay, Annabelle; Gancheva, Vyara; Houghton, Julie; Strada, Anna; Sora, Beatriz; Sala, Roser; Rowe, Gene; University of Exeter; Department of Geography; College of Life and Environmental Sciences; University of Exeter; Exeter UK; Association APPEL EUROPA; Sofia Bulgaria; et al. (Wiley, 2015-01)
      Food allergy is an increasing problem worldwide. Allergy to peanuts is a particular concern, given that this is rarely outgrown and may be associated with life-threatening anaphylaxis. However, it is unclear what factors are responsible for a perceived increase in prevalence rates. One matter on which scientists agree, however, is that exposure to peanuts early in life is significant – although whether early exposure protects or sensitizes to allergy is unclear. There is no significant research that currently records differences in early life exposure either within or between populations. This exploratory study makes a first step in this direction using focus groups conducted in four countries with disparate ‘peanut experiences’ to characterize early exposure in these. The ultimate aim is to help in the development of a survey instrument to attain nationally representative samples of consumers and hence to use the results from this to compare with allergy prevalence data collected in other parts of the European Union-funded ‘EuroPrevall’ project. The results in this study not only reveal considerable similarities across countries (e.g. in terms of lack of knowledge of guidelines; lack of changes in feeding behaviour during/after pregnancy, feelings that diet variety in children is important) but also one or two interesting and potentially important differences, such as increased consumption in Bulgarian (and some Spanish) breastfeeding mothers because of the ability of peanuts to facilitate lactation. Study limitations and future study intentions are also discussed.
    • Performance of aquatic plant species for phytoremediation of arsenic-contaminated water

      Jasrotia, Shivakshi; Kansal, Arun; Mehra, Aradhana; University of Derby (Springer, 2015-06-17)
      This study investigates the effectiveness of aquatic macrophyte and microphyte for phytoremediation of water bodies contaminated with high arsenic concentration. Water hyacinth (Eichhornia crassipes) and two algae (Chlorodesmis sp. and Cladophora sp.) found near arsenic-enriched water bodies were used to determine their tolerance toward arsenic and their effectiveness to uptake arsenic thereby reducing organic pollution in arsenic-enriched wastewater of different concentrations. Parameters like pH, chemical oxygen demand (COD), and arsenic concentration were monitored. The pH of wastewater during the course of phytoremediation remained constant in the range of 7.3–8.4, whereas COD reduced by 50–65 % in a period of 15 days. Cladophora sp. was found to survive up to an arsenic concentration of 6 mg/L, whereas water hyacinth and Chlorodesmis sp. could survive up to arsenic concentrations of 2 and 4 mg/L, respectively. It was also found that during a retention period of 10 days under ambient temperature conditions, Cladophora sp. could bring down arsenic concentration from 6 to <0.1 mg/L, Chlorodesmis sp. was able to reduce arsenic by 40−50 %; whereas, water hyacinth could reduce arsenic by only 20 %. Cladophora sp. is thus suitable for co-treatment of sewage and arsenic-enriched brine in an algal pond having a retention time of 10 days. The identified plant species provides a simple and cost-effective method for application in rural areas affected with arsenic problem. The treated water can be used for irrigation.
    • Permeability of intertidal sandflats: impact of temporal variability on sediment metabolism

      Zetzche, E.; Bulling, Mark T.; Witte, U. (2013-05-24)
      The effects of sediment permeability on sediment oxygen consumption (SOC) in an intertidal permeable sandflat were studied over a 1-year period. Our study demonstrates that temporal variation in sediment metabolism was not only driven by temperature, but also changes in sediment permeability and total carbon content over time. High SOC rates in the summer months (seasonal mean 36.5 mmol m−2 d−1) could be attributed to high temperatures affecting metabolic processes, the rapid turnover of labile organic material and the presence of large amounts of microphytobenthos and their exudates in interstitial pore spaces. The resultant clogging of pores lowered sediment permeabilities and led to the observation of increasing SOC rates at decreasing permeabilities. Despite higher permeabilities, oxygen consumption rates in winter (seasonal mean 17.3 mmol m−2 d−1) were less than half those measured in the summer, reflecting the presence of more persistent refractory material and lower temperatures. During the winter, a major storm event reworked the sediment and significantly changed the permeability, affecting SOC rates. As sediment permeability rose by ∼25%, SOC rates were increased by ∼35% in the month after the event compared to the previous month. Our results show that temporal variation, not only in temperature and carbon content, but also in sediment permeability, affects sediment metabolism and that resuspension and storm events are necessary to unclog systems and maintain high remineralisation rates in organically poor permeable sands.
    • Planning for cooler cities: A framework to prioritise green infrastructure to mitigate high temperatures in urban landscapes.

      Norton, Briony, A.; Coutts, Andrew M.; Livesley, Stephen J.; Harris, Richard J.; Hunter, Annie M.; Williams, Nicholas S. G.; University of Melbourne; Monash University (Elsevier, 2014-11-11)
      Warming associated with urban development will be exacerbated in future years by temperature increases due to climate change. The strategic implementation of urban green infrastructure (UGI) e.g. street trees, parks, green roofs and facades can help achieve temperature reductions in urban areas while delivering diverse additional benefits such as pollution reduction and biodiversity habitat. Although the greatest thermal benefits of UGI are achieved in climates with hot, dry summers, there is comparatively little information available for land managers to determine an appropriate strategy for UGI implementation under these climatic conditions. We present a framework for prioritisation and selection of UGI for cooling. The framework is supported by a review of the scientific literature examining the relationships between urban geometry, UGI and temperature mitigation which we used to develop guidelines for UGI implementation that maximises urban surface temperature cooling. We focus particularly on quantifying the cooling benefits of four types of UGI: green open spaces (primarily public parks), shade trees, green roofs, and vertical greening systems (green walls and facades) and demonstrate how the framework can be applied using a case study from Melbourne, Australia.
    • Plant species or flower colour diversity? Identifying the drivers of public and invertebrate response to designed annual meadows.

      Hoyle, Helen; Norton, Briony, A.; Dunnett, Nigel; Richards, J. Paul; Russell, Jean M.; Warren, Philip H.; University of Sheffield (Elsevier, 2018-09-01)
      There is increasing evidence of the benefits of introducing urban meadows as an alternative to amenity mown grass in public greenspaces, both for biodiversity, and human wellbeing. Developing a better understanding of the meadow characteristics driving human and wildlife response is therefore critical. We addressed this by assessing public and invertebrate response to eight different annual meadow mixes defined by two levels of plant species diversity and two levels of colour diversity, sown in an urban park in Luton, UK, in April 2015. On-site questionnaires with the visiting public were conducted in July, August and September 2015. Invertebrate responses were assessed via contemporaneous visual surveys and one sweep net survey (August 2015). Flower colour diversity had effects on human aesthetic response and the response of pollinators such as bumblebees and hoverflies. Plant species diversity, however, was not a driver of human response with evidence that people used colour diversity as a cue to assessing species diversity. Plant species diversity did affect some invertebrates, with higher abundances of certain taxa in low species diversity meadows. Our findings indicate that if the priority for sown meadows is to maximise human aesthetic enjoyment and the abundance and diversity of observable invertebrates, particularly pollinators, managers of urban green infrastructure should prioritise high flower colour diversity mixes over those of high plant species diversity. Incorporating late-flowering non-native species such as Coreopsis tinctoria (plains coreopsis) can prolong the attractiveness of the meadows for people and availability of resources for pollinators and would therefore be beneficial.
    • Polymerase chain reaction detection of avipox and avian papillomavirus in naturally infected wild birds: comparisons of blood, swab and tissue samples

      Williams, Richard; Escudero Duch, Clara; Pérez-Tris, Javier; Benítez, Laura; Department of Zoology and Physical Anthropology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Spain; Natural Sciences, Saint Louis University, Madrid, Spain; Department of Microbiology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Madrid, Spain (Taylor & Francis Group, 2014-03-04)
      Avian poxvirus (avipox) is widely reported from avian species, causing cutaneous or mucosal lesions. Mortality rates of up to 100% are recorded in some hosts. Three major avipox clades are recognized. Several diagnostic techniques have been reported, with molecular techniques used only recently. Avipox has been reported from 278 different avian species, but only 111 of these involved sequence and/or strain identification. Collecting samples from wild birds is challenging as only few wild bird individuals or species may be symptomatic. Also, sampling regimes are tightly regulated and the most efficient sampling method, whole bird collection, is ethically challenging. In this study, three alternative sampling techniques (blood, cutaneous swabs and tissue biopsies) from symptomatic wild birds were examined. Polymerase chain reaction was used to detect avipoxvirus and avian papillomavirus (which also induces cutaneous lesions in birds). Four out of 14 tissue samples were positive but all 29 blood samples and 22 swab samples were negative for papillomavirus. All 29 blood samples were negative but 6/22 swabs and 9/14 tissue samples were avipox-positive. The difference between the numbers of positives generated from tissue samples and from swabs was not significant. The difference in the avipox-positive specimens in paired swab (4/6) and tissue samples (6/6) was also not significant. These results therefore do not show the superiority of swab or tissue samples over each other. However, both swab (6/22) and tissue (8/9) samples yielded significantly more avipox-positive cases than blood samples, which are therefore not recommended for sampling these viruses.
    • The potential of fatty acid isotopes to trace trophic transfer in aquatic food-webs

      Burian, Alfred; Nielsen, Jens M.; Hansen, Thomas; Bermudez, Rafael; Winder, Monika; University of Derby; Stockholm University; Helmholtz Centre for Ocean Research Kiel (GEOMAR), Kiel, Germany; Escuela Superior Politécnica del Litoral, ESPOL, Guayaquil, Ecuador (The Royal Society, 2020-06-15)
      Compound-specific isotope analyses (CSIA) of fatty acids (FA) constitute a promising tool for tracing energy flows in food-webs. However, past applications of FA-specific carbon isotope analyses have been restricted to a relatively coarse food-source separation and mainly quantified dietary contributions from different habitats. Our aim was to evaluate the potential of FA-CSIA to provide high-resolution data on within-system energy flows using algae and zooplankton as model organisms. First, we investigated the power of FA-CSIA to distinguish among four different algae groups, namely cyanobacteria, chlorophytes, haptophytes and diatoms. We found substantial within-group variation but also demonstrated that δ13C of several FA (e.g. 18:3ω3 or 18:4ω3) differed among taxa, resulting in group-specific isotopic fingerprints. Second, we assessed changes in FA isotope ratios with trophic transfer. Isotope fractionation was highly variable in daphnids and rotifers exposed to different food sources. Only δ13C of nutritionally valuable poly-unsaturated FA remained relatively constant, highlighting their potential as dietary tracers. The variability in fractionation was partly driven by the identity of food sources. Such systematic effects likely reflect the impact of dietary quality on consumers' metabolism and suggest that FA isotopes could be useful nutritional indicators in the field. Overall, our results reveal that the variability of FA isotope ratios provides a substantial challenge, but that FA-CSIA nevertheless have several promising applications in food-web ecology. This article is part of the theme issue ‘The next horizons for lipids as ‘trophic biomarkers’: evidence and significance of consumer modification of dietary fatty acids’.
    • Potential of Retrofitting Sustainable Urban Drainage Systems Using an Integrated Geographical Information System Remote Sensing Based Approach

      Ferrier, G.; Milan, D.; Keat Yew, C.; Pope, R.J.; University of Hull; University of Derby (2018-12-06)
      Flooding is a major problem in urban areas worldwide. Methodologies that can rapidly assess the scale and identify the reasons causing these flooding events at minimal cost are urgently required. This study has used the City of Kingston-upon-Hull to evaluate the capability of an integrated remote sensing and geographical information system based approach to provide the critical information on the spatial extent of flooding and flood water volumes and overcome the limitations in current monitoring based on ground-based visual mapping and household flooding surveys. Airborne and Terrestrial LiDAR datasets were combined with digital aerial photography, flood assessment surveys, and maps of housing, infrastructure and the sewer network. The integration of these datasets provided an enhanced understanding of the sources and pathways of the flood water runoff, accurate quantification of the water volumes associated with each flooding event and the identification of the optimum locations and size of potential retrofit Sustainable Urban Drainage systems.
    • Predictable waves of sequential forest degradation and biodiversity loss spreading from an African city

      Ahrends, Antje; Burgess, Neil D.; Milledge, Simon A. H.; Bulling, Mark T.; Fisher, Brendan; Smart, James C. R.; Clarke, G. P.; Mhoro, Boniface E.; Lewis, Simon L. (2013-05-24)
      Tropical forest degradation emits carbon at a rate of ~0.5 Pg·y−1, reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 km·y−1, and an inner wave of lower value charcoal production 2 km·y−1. This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mg·ha−1; 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity.
    • Predicting European badger Meles meles sett distribution in urban environments

      Huck, Maren; Davison, John; Roper, Timothy J.; University of Sussex (the Nordic Council for Wildlife Research, 2008)
      Natural England receives an increasing number of complaints about problems caused by badgers Meles meles in urban and suburban environments, most of which concern problems caused by the digging of burrows (setts). The aim of our study was to identify factors related to the presence of badger setts in urban and suburban areas, in order to provide information relevant to the development of an urban badger management strategy. We identified habitat factors (including human population density) associated with the presence of badger setts in four extensively surveyed towns or cities in England, in a GIS-based approach using binary logistic regression analysis. Badger sett densities in urban areas were comparable to sett densities in most rural parts of the UK. Thus, badgers can achieve relatively high population densities in urban environments, despite the potential for human-badger conflict. The single most important factor predicting sett location was the type of habitat in which the sett in question was located, followed by the slope of the ground at that location. Sett presence was also predicted by the proximity of other setts, and badgers preferred areas with intermediate human population densities. The population density of badgers in urban and suburban environments appears to be mainly related to the availability of suitable places for locating setts, rather than to factors that would be expected to reflect food availability. This information will help to predict potential sites of badger-related problems and may be relevant to understanding the ecological requirements of other carnivore species that inhabit urban environments, such as red fox Vulpes vulpes, stone marten Martes foina and racoon Procyon lotor.
    • Prevalence and genetic diversity of Avipoxvirus in house sparrows in Spain

      Ruiz-Martinez, Jorge; Ferraguti, Martina; Figuerola, Jorge; Martinez-de la Puente, Josue; Williams, Richard; Herrera-Duenas, Amparo; Aguirre, Jose I; Soriguer, R; Escudero-Duch, Clara; Moens, Mikael, AJ; et al. (Public Library of Science, 2016-12-22)
      Avipoxvirus (APV) is a fairly common virus affecting birds that causes morbidity and mortality in wild and captive birds. We studied the prevalence of pox-like lesions and genetic diversity of APV in house sparrows (Passer domesticus) in natural, agricultural and urban areas in southern Spain in 2013 and 2014 and in central Spain for 8 months (2012±2013). Overall, 3.2% of 2,341 house sparrows visually examined in southern Spain had cutaneous lesions consistent with avian pox. A similar prevalence (3%) was found in 338 birds from central Spain. Prevalence was higher in hatch-year birds than in adults. We did not detect any clear spatial or temporal patterns of APV distribution. Molecular analyses of poxvirus-like lesions revealed that 63% of the samples were positive. Molecular and phylogenetic analyses of 29 DNA sequences from the fpv167 gene, detected two strains belonging to the canarypox clade (subclades B1 and B2) previously found in Spain. One of them appears predominant in Iberia and North Africa and shares 70% similarity to fowlpox and canarypox virus. This APV strain has been identified in a limited number of species in the Iberian Peninsula, Morocco and Hungary. The second one has a global distribution and has been found in numerous wild bird species around the world. To our knowledge, this represents the largest study of avian poxvirus disease in the broadly distributed house sparrow and strongly supports the findings that Avipox prevalence in this species in South and central Spain is moderate and the genetic diversity low.
    • Prevalence and Incidence of Black Band Disease of Scleractinian Corals in the Kepulauan Seribu Region of Indonesia

      Johan, Ofri; Zamani, Neviaty P. Zamani; Smith, David; Sweet, Michael J.; University of Derby (2016-04-28)
      Black band disease (BBD) is the oldest recognised disease associated with scleractinian corals. However, despite this, few BBD surveys have been conducted in the Indonesian archipelago,one of the world’s hot spots for coral diversity. In this study, we show that BBD was recorded in the reefs of Kepulauan Seribu, Indonesia, at the time of surveying. The disease was found to mainly infect corals of the genus Montipora. In some instances, upwards of 177 colonies (31.64%) were found to be infected at specific sites. Prevalence of the disease ranged from 0.31% to 31.64% of Montipora sp. colonies throughout the archipelago. Although BBD was found at all sites, lower frequencies were associated with sites closest to the mainland (17.99 km), as well as those that were furthest away (63.65 km). Despite there being no linear relationship between distance from major population centers and BBD incidence, high incidences of this disease were associated with sites characterized by higher levels of light intensity. Furthermore, surveys revealed that outbreaks peaked during the transitional period between the dry and rainy seasons. Therefore, we suggest that future surveys for disease prevalence in this region of Indonesia should focus on these transitory periods.
    • Promoting interactive learning: A classroom exercise to explore foraging strategies

      Beaumont, Ellen S.; Rowe, Graham; Mikhaylov, Natalie S.; University of Derby; Universidad Especialidades Espiritu Santo (Taylor and Francis, 2012-12)
      We describe a classroom exercise to allow students to explore foraging strategies in higher vertebrates. The exercise includes an initial interactive session in which students act as predators and are guided through foraging simulations, and a subsequent student-led session where classmates are employed as experimental subjects. Students rated the exercise, which utilises only cheap and widely available resources, significantly more highly than another more traditional module element in terms of development of both biological understanding and transferable skills for the workplace. As current trends are towards making tertiary level bioscience teaching more challenging and engaging, our experiences with this exercise support its introduction on a larger scale to undergraduate biology and ecology curricula.
    • Proximate mechanisms of reproductive monopolization in male moustached tamarins (Saguinus mystax)

      Huck, Maren; Löttker, Petra; Heymann, Eckhard W.; German Primate Centre (2004)
      In moustached tamarin (Saguinus mystax) groups, the single breeding female mates polyandrously with most or all nonrelated adult males. Nonetheless, paternity is monopolized in many groups by a single male. No evidence for male endocrine suppression has been found in this species. The proximate mechanisms of monopolization thus remain poorly understood. The aim of this study was to investigate the possible impact of agonistic interactions and mate-guarding on the monopolization of paternity in male moustached tamarins. Furthermore, we evaluated the likely costs of these behaviors, and whether olfactory cues might be used for its timing. We used behavioral data on proximity, agonistic interactions, time budgets, and scent-marking behavior to answer these questions. While direct agonistic competition does not play a prominent role, fertile females were consorted in some periods by one male, the sire of the previous and next litter. Consorting was instigated nearly exclusively by the male. It probably occurred during the female’s periods of highest fertility, and thus likely functions as mate-guarding. The timing of the consortship was probably guided by olfactory cues in the female’s scent marks. While we did not obtain direct evidence for energy costs in terms of increased energy expenditure or decreased food intake, we found that consorting males are more conspicuous and therefore may be more vulnerable to predators.
    • Quantifying individual feeding variability: implications for mollusc feeding experiments

      Hanley, M. E.; Bulling, Mark T.; Fenner, M. (2013-05-24)
      1. In order to quantify the level of variability in seedling consumption displayed by individual molluscs, we placed one snail ( Helix aspersa ) in each of 51 trays containing (7-day-old) Taraxacum officinale seedlings for 7 days. 2. Initially, individual snails displayed considerable variability in their consumption of seedlings; however, this variability declined with time. The consumption of seedlings was not related to individual snail mass. 3. A second grazing experiment, using five different snail densities in similar experi- mental conditions to the first, showed that increasing snail number reduced variability within treatment groups. 4. A computer simulation, based on data from the first experiment correctly predicted the basic form of the decline in feeding variability with increasing snail density found in the second. Post hoc changes to the model, based on empirical analysis of the second experiment to account for mutual interference, reduced discrepancies between empirical and model results. 5. This study highlights the consequences that individual feeding behaviour has on feeding trials with molluscs, and provides a simple method by which this variability can be quantified and accommodated within experimental design.
    • Quantitative mapping of alluvial fan evolution using ground-based reflectance spectroscopy

      Ferrier, Graham; Pope, Richard J. J.; University of Hull; University of Derby (2012)
      The ability of field-based reflectance spectroscopy to resolve the relative proportions of Fe-oxides and clays in soils was used to map the composition, relative age and distribution of segments within late Quaternary fan systems in Sfakia, southwest Crete. The spectrometric results demonstrate that luvisols that have formed on the surfaces of fan segments are characterized by distinctive Fe-oxides (types) and clay minerals (species). Furthermore, Fe-oxide and clay concentrations display a clear and consistent trend whereby for each study fan luvisols formed on increasingly proximal fan segments are characterized by a progressive build-up of spectrally distinct secondary iron oxides and clay minerals, which suggests that proximal segments formed first. The relative ages and hence order of formation of segments suggested by the spectral data are strongly supported by an optically stimulated luminescence (OSL)-based geochronology which provides a tentative maximum age of 144 ka for the oldest (stage 1) surface and 11.2 ka for the youngest (stage 2C) surface. Moreover, the chronometric data indicate that time intervals of the order 20 to 25,000 years are necessary to generate sufficient differences in pedogenic Fe-oxides and clay concentrations to enable differentiation of fan segments by field spectroscopy. ⺠Field-based reflectance spectroscopy was used to map alluvial fan segments. ⺠Strong relationships between spectral profiles and soil composition were identified. ⺠Fan segments were differentiated using time interval between depositional events. ⺠Age differences of 25,000 years are required to differentiate fan segments.
    • Rain-fed granite rock basins accumulate a high diversity of dormant microbial eukaryotes

      Velasco-González, Ismael; Sanchez-Jimenez, Abel; Singer, David; Murciano, Antonio; Díez-Hermano, Sergio; Lara, Enrique; Martín-Cereceda, Mercedes; Departamento de Genética, Fisiología y Microbiología. Facultad de Ciencias Biológicas, Universidad Complutense de Madrid (UCM), C/ José Antonio Novais 12, 28040, Madrid, Spain; Departamento de Biodiversidad, Ecología y Evolución. Facultad de Ciencias Biológicas, UCM, Madrid, Spain; University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland; et al. (Springer Science and Business Media LLC, 2019-12-03)
      Rain fed granite rock basins are ancient geological landforms of worldwide distribution and structural simplicity. They support habitats that can switch quickly from terrestrial to aquatic along the year. Diversity of animals and plants, and the connexion between communities in different basins have been widely explored in these habitats, but hardly any research has been carried out on microorganisms. The aim of this study is to provide the first insights on the diversity of eukaryotic microbial communities from these environments. Due to the ephemeral nature of these aquatic environments, we predict that the granitic basins should host a high proportion of dormant microeukaryotes. Based on an environmental DNA diversity survey, we reveal diverse communities with representatives of all major eukaryotic taxonomic supergroups, mainly composed of a diverse pool of low abundance OTUs. Basin communities were very distinctive, with alpha and beta diversity patterns non-related to basin size or spatial distance respectively. Dissimilarity between basins was mainly characterised by turnover of OTUs. The strong microbial eukaryotic heterogeneity observed among the basins may be explained by a complex combination of deterministic factors (diverging environment in the basins), spatial constraints, and randomness including founder effects. Most interestingly, communities contain organisms that cannot coexist at the same time because of incompatible metabolic requirements, thus suggesting the existence of a pool of dormant organisms whose activity varies along with the changing environment. These organisms accumulate in the pools, which turns granitic rock into high biodiversity microbial islands whose conservation and study deserve further attention.
    • Rapid assembly of high-Mg andesites and dacites by magma mixing at a continental arc stratovolcano

      Conway, Chris; Chamberlain, Katy J.; Harigane, Yumiko; Morgan, Daniel; Wilson, Colin; Research Institute of Earthquake and Volcano Geology, Japan; National Museum of Nature and Science, Japan; University of Derby; University of Leeds; Victoria University of Wellington (The Geological Society of America, 2020-06-25)
      Studies of pre-eruptive processes at active volcanoes require precise petrochronological constraints if they are to contribute to hazard assessment during future eruption events. We present petrological and geochemical data, and orthopyroxene diffusion timescales for samples from late Pleistocene high-Mg andesite dacite lavas (Mg#53–69) at Ruapehu volcano, New Zealand, as a case study of rapid magma genesis and eruption at a continental arc stratovolcano. Assembly of Ruapehu high-Mg magmas involved the mixing of primitive magmas plus entrained mantle equilibrated olivines with mid-crustal felsic mush bodies, yielding hybridized magmas with ubiquitous pyroxene reverse-zoning patterns. Orthopyroxene Fe-Mg interdiffusion timescales linked to quantitative crystal orientation data show that most lavas erupted <10 days after resumption of crystal growth following magma mixing events. The eruption of lavas within days of mixing events implies that pre-eruptive warnings may be correspondingly short.