Hydroclimate in Africa during the Medieval Climate Anomaly

The Medieval Climate Anomaly (MCA) is a recognized period of distinct pre-industrial climate change, with a core period of 1000–1200 CE. The field of palaeoclimatology has made major progress over the past 15 years during which a great number of high- and medium-resolution case studies were published, reconstructing climate change of the past millennia. In many parts of the world, regional data coverage has now reached a point which allows compiling palaeoclimate maps for well-defined time intervals. Here we present hydroclimatic trend maps for the MCA in Africa based on 99 published study locations. Key hydroclimatic proxy curves are visualized and compared in a series of 16 correlation panels. Proxy types are described and possible issues discussed. Based on the combined MCA dataset, temporal and spatial trends are interpreted and mapped out. Three areas have been identified in Africa in which rainfall seems to have increased during the MCA, namely Tunisia, western Sahel and the majority of southern Africa. At the same time, a reduction in precipitation occurred in the rest of Africa, comprising of NW and NE Africa, West Africa, Eastern Africa and the Winter Rainfall Zone of South Africa. MCA hydroclimate change in Africa appears to have been associated with characteristic phases of ocean cycles, as also supported by modern climate observations. Aridity in Morocco typically coincides with the positive phase of the North Atlantic Oscillation (NAO), whilst increased rainfall in the western Sahel is often coupled to the positive phase of the Atlantic Multidecadal Oscillation (AMO). Reduction in rainfall in the region Gulf of Aden/southern Red Sea to Eastern Africa could be linked to a negative Indian Ocean Dipole (IOD) or a derived long-term equivalent Indian Ocean cycle parameter. The Intertropical Convergence Zone (ITCZ) appears to have been shifted pole-wards during the MCA, for both the January and July positions. MCA hydroclimate mapping revealed major data gaps in the Sahara, South Sudan, Somalia, Central African Republic, Democratic Republic of Congo, Angola, northern Mozambique, Zambia and Zimbabwe. Special efforts are needed to fill these gaps, e.g. through a dedicated structured research program in which new multiproxy datasets are created, based on the learnings from previous African MCA studies

Multi-Color Imaging of Magnetic Co/Pt Multilayers

We demonstrate for the first time the realization of a spatial resolved two color, element-specific imaging experiment at the free-electron laser facility FERMI. Coherent imaging using Fourier transform holography was used to achieve direct real space access to the nanometer length scale of magnetic domains of Co/Pt heterostructures via the element-specific magnetic dichroism in the extreme ultraviolet spectral range. As a first step to implement this technique for studies of ultrafast phenomena we present the spatially resolved response of magnetic domains upon femtosecond laser excitation

Evaluation of 0 <_ M <_ earthquake data sets in African – Asian region during 1966–2015

Thisarticleevaluatestheoccurrenceof0 r M r 8 earthquakedata setsfortheperiodof50years(thatis,January1,1966toDecember 31,2015)inAfricanandWesternAsiaregion.Itisboundedby latitude40° S to40° N andlongitude30° W to60° E withthefocal depthof0–700km.Seventyseventhousand,sixhundredand ninety-sixdatapointswerepresentedfortheanalysis.Thedata usedwereextractedfromearthquakecatalogofAdvancedNational Seismicsystemvia http://quake.geo.berkeley.edu/cnss/, anofficial websiteoftheNorthernCaliforniaEarthquakeDataCentre,USA. Eachdatumcomprisedtheearthquakeoccurrencedate,timeofthe earthquakeoccurrence,epicenter’s coordinates,focaldepthand magnitude.TheGutenberg-Richter’s relationshipbeingthelongest observedempiricalrelationshipinseismology,analysisofvariance andtimeserieswereusedtoanalyzetheseismicityofthestudy area.Annualdistributionsofearthquakeoccurrencebasedon magnitudevariationswiththelimit0 r M r 8 werepresented. ThetwoconstantsaandbintheGutenberg-Richter’s equation, magnitudeofcompleteness(MC)adjustedR-Squareand F-valuefor theperiodof1966–1975,1976–1985,1986–1995,1996–2005,2006– 2015,andtheentireperiodofinvestigationrangingfrom1966to 2015weredeterminedsoastoinvestigatethevariationsofthese parametersonearthquakeoccurrenceovertime.Thehistogramsof earthquakeoccurrenceagainstmagnitudeofearthquakesforthe selectedyears(1966–1975,1976–1985,1986–1995,1996–2005, 2006–2015,and1966–2015),andthedecadalfrequencydistribu- tionsofearthquakeoccurrencewerealsoplotted.Thefocaldepth occurrenceforeachmagnitudebins(0–0.9,1–1.9,2–2.9,3–3.9,4– 4.9,5–5.9,6–6.9,7–7.9,8–8.9)weregroupedintoshallow,inter- mediate,anddeepdepthsrangingfrom0to70,71to300,and301 to700kmasbeingusedinseismology.Theneuralnetworkanalysis wasalsoappliedtothemagnitudeoftheearthquake.Thenetwork usesatimeseriesmagnitudedataasinputwiththeoutputbeing themagnitudeofthefollowingday.Ifthenatureoftheearthquakes timeseriesisstochastic,modelingandpredictionispossible.The earthquakedatasetspresentedinthisarticlecanfurtherbeadopted in thestudyofseismicitypattern, b-valueusingseriesofmodels, earthquakepredictionandvariationsofearthquakeparameterson Africanand/orArabianplates.Whenthisapproachisintegrated withothertechnique(s),itcanprovideinsightstostabilityof African lithospehricplatesespeciallythecoastalregionofAfrica

Lossof a chloroplast encoded function could influence species range in kelp

Kelps are important providers and constituents of marine ecological niches, the coastal kelp forests. Kelp species have differing distribution ranges, but mainly thrive in temperate and arctic regions. Although the principal factors determining biogeographic distribution ranges are known, genomics could provide additional answers to this question. We sequenced DNA from two Laminaria species with contrasting distribution ranges, Laminaria digitata and Laminaria solidungula. Laminaria digitata is found in the Northern Atlantic with a southern boundary in Brittany (France) or Massachusetts (USA) and a northern boundary in the Arctic, whereas L. solidungula is endemic to the Arctic only. From the raw reads of DNA, we reconstructed both chloroplast genomes and annotated them. A concatenated data set of all available brown algae chloroplast sequences was used for the calculation of a robust phylogeny, and sequence variations were analyzed. The two Laminaria chloroplast genomes are collinear to previously analyzed kelp chloroplast genomes with important exceptions. Rearrangements at the inverted repeat regions led to the pseudogenization of ycf37 in L. solidungula, a gene possibly required under high light conditions. This defunct gene might be one of the reasons why the habitat range of L. solidungula is restricted to lowlight sublittoral sites in the Arctic. The inheritance pattern of single nucleotide polymorphisms suggests incomplete lineage sorting of chloroplast genomes in kelp species. Our analysis of kelp chloroplast genomes shows that not only evolutionary information could be gleaned from sequence data. Concomitantly, those sequences can also tell us something about the ecological conditions which are required for species well‐being

Integrating reproductive phenology in ecological niche models changed the predicted future ranges of a marine invader

Aim Phenology of a wide diversity of organisms has a dependency on climate, usually with reproductive periods beginning earlier in the year and lasting longer at lower latitudes. Temperature and day length are known environmental drivers of the reproductive timing of many species. Hence, reproductive phenology is sensitive to warming and is important to be considered for reliable predictions of species distributions. This is particularly relevant for rapidly spreading non-indigenous species (NIS). In this study, we forecast the future ranges of a NIS, the seaweed Sargassum muticum, including its reproductive phenology. Location Coastal areas of the Northern Hemisphere (Pacific and Atlantic oceans). Methods We used ecological niche modelling to predict the distribution of S. muticum under two scenarios forecasting limited (RCP 2.6) and severe (RCP 8.5) future climate changes. We then refined our predictions with a hybrid model using sea surface temperature constraints on reproductive phenology. Results Under the most severe climate change scenario, we predicted northward expansions which may have significant ecological consequences for subarctic coastal ecosystems. However, in lower latitudes, habitats currently occupied by S. muticum will no longer be suitable, creating opportunities for substantial community changes. The temperature constraints imposed by the reproductive window were shown to restrict the modelled future species expansion strongly. Under the RCP 8.5 scenario, the total range area was expected to increase by 61.75% by 2100, but only by 1.63% when the reproductive temperature window was considered. Main conclusions Altogether these results exemplify the need to integrate phenology better to improve the prediction of future distributional shifts at local and regional scales.Agência financiadora Número do subsídio Fundacao para a Ciencia e a Tecnologia CCMAR/Multi/04326/2019 FCT-BIODIVERSA/004/2015 FCT-SEAS-ERA/0001/2012 SFRH/BPD/107878/2015 SFRH/BPD/85040/2012 Erasmus Mundus Doctoral Programme MARES on Marine Ecosystem Health Conservation MARES_13_08 Pew Marineinfo:eu-repo/semantics/publishedVersio

Heat stress responses and population genetics of the kelp Laminaria digitata (Phaeophyceae) across latitudes reveal differentiation among North Atlantic populations

To understand the thermal plasticity of a coastal foundation species across its latitudinal distribution, we assess physiological responses to high temperature stress in the kelp Laminaria digitata in combination with population genetic characteristics and relate heat resilience to genetic features and phylogeography. We hypothesize that populations from Arctic and cold-temperate locations are less heat resilient than populations from warm distributional edges. Using meristems of natural L. digitata populations from six locations ranging between Kongsfjorden, Spitsbergen (79°N), and Quiberon, France (47°N), we performed a common-garden heat stress experiment applying 15°C to 23°C over eight days. We assessed growth, photosynthetic quantum yield, carbon and nitrogen storage, and xanthophyll pigment contents as response traits. Population connectivity and genetic diversity were analyzed with microsatellite markers. Results from the heat stress experiment suggest that the upper temperature limit of L. digitata is nearly identical across its distribution range, but subtle differences in growth and stress responses were revealed for three populations from the species' ecological range margins. Two populations at the species' warm distribution limit showed higher temperature tolerance compared to other populations in growth at 19°C and recovery from 21°C (Quiberon, France), and photosynthetic quantum yield and xanthophyll pigment responses at 23°C (Helgoland, Germany). In L. digitata from the northernmost population (Spitsbergen, Norway), quantum yield indicated the highest heat sensitivity. Microsatellite genotyping revealed all sampled populations to be genetically distinct, with a strong hierarchical structure between southern and northern clades. Genetic diversity was lowest in the isolated population of the North Sea island of Helgoland and highest in Roscoff in the English Channel. All together, these results support the hypothesis of moderate local differentiation across L. digitata's European distribution, whereas effects are likely too weak to ameliorate the species' capacity to withstand ocean warming and marine heatwaves at the southern range edge.Foundation for Science and Technology: UIDB/04326/2020/ PTDC/MAR-EST/6053/2014/ Biodiversa/0004/2015info:eu-repo/semantics/publishedVersio

Temporal variations of vegetative features, sex ratios and reproductive phenology in a Dictyota dichotoma (Dictyotales, Phaeophyceae) population of Argentina

This paper addresses the phenology of a Dictyota dichotoma population from the North Patagonian coasts of Argentina. The morphology of the individuals was characterized, and analyses of the temporal variations of vegetative features, diploid and haploid life cycle generations and sex ratios are provided. Individuals, represented by growing sporophytes and gametophytes, occurred simultaneously throughout the year. Morphological variables showed temporal variation, except the width and height of medullary cells, which did not vary between seasons. All vegetative variables were significantly correlated with daylength. Besides, frond length, frond dry mass and apical and basal branching angles were significantly correlated with seawater temperatures. Vegetative thalli were less abundant than haploid and diploid thalli. Sporophytes were less abundant than male and female gametophytes. Male gametophytes dominated in May, August, October and January, and female gametophytes were more abundant in September, November, December, February and March. The formation of female gametangia showed a significant correlation with daylength, and the highest number of gametangia was registered in spring. In general, the male/female sex ratio varied between 1:2 and 1:1. Apical regions were more fertile than basal regions. Our data about frequency in the formation of reproductive structures and male/female ratios are the first recorded in the Dictyota genus and thus could not be compared with populations from other regions of the world. Significant morphological variation was observed in thalli of both life cycle generations, regarding length and dry mass, number of primary branches and branching basal angle. In general, all variables analyzed varied seasonally except cortical cell width.Fil: Gauna, Maria Cecilia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Caceres, Eduardo Jorge. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ficología y Micología; ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; Argentin

Evaluationof0 r M r 8 earthquake datasets in African – Asian regionduring1966–2015

Thisarticleevaluatestheoccurrenceof0 r M r 8 earthquakedata setsfortheperiodof50years(thatis,January1,1966toDecember 31,2015)inAfricanandWesternAsiaregion.Itisboundedby latitude40° S to40° N andlongitude30° W to60° E withthefocal depthof0–700km.Seventyseventhousand,sixhundredand ninety-sixdatapointswerepresentedfortheanalysis.Thedata usedwereextractedfromearthquakecatalogofAdvancedNational Seismicsystemvia http://quake.geo.berkeley.edu/cnss/, anofficial websiteoftheNorthernCaliforniaEarthquakeDataCentre,USA. Eachdatumcomprisedtheearthquakeoccurrencedate,timeofthe earthquakeoccurrence,epicenter’s coordinates,focaldepthand magnitude.TheGutenberg-Richter’s relationshipbeingthelongest observedempiricalrelationshipinseismology,analysisofvariance andtimeserieswereusedtoanalyzetheseismicityofthestudy area.Annualdistributionsofearthquakeoccurrencebasedon magnitudevariationswiththelimit0 r M r 8 werepresented. ThetwoconstantsaandbintheGutenberg-Richter’s equation, magnitudeofcompleteness(MC)adjustedR-Squareand F-valuefor theperiodof1966–1975,1976–1985,1986–1995,1996–2005,2006– 2015,andtheentireperiodofinvestigationrangingfrom1966t

Deep-water macroalgae from the Canary Islands: new records and biogeographical relationships

Due to the geographical location and paleobiogeography of the Canary Islands, the seaweed flora contains macroalgae with different distributional patterns. In this contribution, the biogeographical relations of several new records of deep-water macroalgae recently collected around the Canarian archipelago are discussed. These are Bryopsidella neglecta (Berthotd) Rietema,Discosporangium mesarthrocarpum (Meneghini) Hauck, Hincksia onslowensis (Amsler et Kapraun)P.C. Silva, Syringoderma floridana Henry, Peyssonnelia harveyana J. Agardh, Cryptonemia seminervis(C. Agardh) J. Agardh, Botryodadia wynnei Ballantine, Gloiocladia blomquistii (Searles) R. E.Norris, PIahchrysis peltata (W. R. Taylor) P. Huv4 et H. Huv4, Leptofauchea brasiliensis Joly, and Sarcodiotheca divaricata W. R. Taylor. These new records, especially those in the Florideophyceae,support the strong affinity of the Canary Islands seaweed flora with the warm-temperate Mediterranean-Atlantic region. Some species are recorded for the first time from the east coast of the Atlantic Ocean, enhancing the biogeographic relations of the Canarian marine flora with that of the western Atlantic regions

A new method to quantify and compare the multiple components of fitness-A study case with kelp niche partition by divergent microstage adaptations to Temperature

Point 1 Management of crops, commercialized or protected species, plagues or life-cycle evolution are subjects requiring comparisons among different demographic strategies. The simpler methods fail in relating changes in vital rates with changes in population viability whereas more complex methods lack accuracy by neglecting interactions among vital rates. Point 2 The difference between the fitness (evaluated by the population growth rate.) of two alternative demographies is decomposed into the contributions of the differences between the pair-wised vital rates and their interactions. This is achieved through a full Taylor expansion (i.e. remainder = 0) of the demographic model. The significance of each term is determined by permutation tests under the null hypothesis that all demographies come from the same pool. Point 3 An example is given with periodic demographic matrices of the microscopic haploid phase of two kelp cryptic species observed to partition their niche occupation along the Chilean coast. The method provided clear and synthetic results showing conditional differentiation of reproduction is an important driver for their differences in fitness along the latitudinal temperature gradient. But it also demonstrated that interactions among vital rates cannot be neglected as they compose a significant part of the differences between demographies. Point 4 This method allows researchers to access the effects of multiple effective changes in a life-cycle from only two experiments. Evolutionists can determine with confidence the effective causes for changes in fitness whereas population managers can determine best strategies from simpler experimental designs.CONICYT-FRENCH EMBASSADY Ph.D. gran