Animal Board Invited Review: Sheep birth distribution in past herds: a review for prehistoric Europe (6th to 3rd millennia BC)

In temperate latitudes sheep have a seasonal reproductive behaviour, which imposes strong constraints on husbandry in terms of work organization and availability of animal products. During the last 50 years, researchers have focused on understanding the mechanisms driving small ruminants’ reproduction cycles and finding ways to control them. This characteristic is inherited from their wild ancestor. However, the history of its evolution over the 10 millennia that separates present day European sheep from their Near Eastern ancestors’ remains to be written. This perspective echoes archaeologists’ current attempts at reconstructing ancient pastoral societies’ socio-economical organization. Information related to birth seasonality may be retrieved directly from archaeological sheep teeth. The methodology consists of reconstructing the seasonal cycle record in sheep molars, through sequential analysis of the stable oxygen isotope composition (δ 18O) of enamel. Because the timing of tooth development is fixed within a species, inter-individual variability in this parameter reflects birth seasonality. A review of the data obtained from 10 European archaeological sites dated from the 6th to the 3rd millennia BC is provided. The results demonstrate a restricted breeding season for sheep: births occurred over a period of 3 to 4 months, from late winter to early summer at latitudes 43°N to 48°N, while a later onset was observed at a higher latitude (59°N). All conclusions concurred with currently held expectations based on present day sheep physiology, which, aside from the historical significance, contributes to the reinforcing of the methodological basis of the approach. Further study in this area will permit regional variability attributable to technical choices, within global schemes, to be fully reported

Impacts of conversion of tropical peat swamp forest to oil palm plantation on peat organic chemistry, physical properties and carbon stocks

Ecosystem services provided by tropical peat swamp forests, such as carbon (C) storage and water regulation, are under threat due to encroachment and replacement of these natural forests by drainage-based agriculture, commonly oil palm plantation. This study aims to quantify how the chemical and physical properties of peat change during land conversion to oil palm. This will be addressed by comparing four separate stages of conversion; namely, secondary peat swamp forests, recently deeply drained secondary forests, cleared and recently planted oil palm, and mature oil palm plantation in North Selangor, Malaysia. Results indicate accelerated peat decomposition in surface peats of mature oil palm plantations due to the lowered water table and altered litter inputs associated with this land-use change. Surface organic matter content and peat C stocks at secondary forest sites were higher than at mature oil palm sites (e.g. C stocks were 975 ± 151 and 497 ± 157 Mg ha− 1 at secondary forest and mature oil palm sites, respectively). Land conversion altered peat physical properties such as shear strength, bulk density and porosity, with mirrored changes above and below the water table. Our findings suggest close links between the organic matter and C content and peat physical properties through the entire depth of the peat profile. We have demonstrated that conversion from secondary peat swamp forest to mature oil palm plantation may seriously compromise C storage and, through its impact on peat physical properties, the water holding capacity in these peatlands

Introducing global peat-specific temperature and pH calibrations based on brGDGT bacterial lipids

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Glycerol dialkyl glycerol tetraethers (GDGTs) are membrane-spanning lipids from Bacteria and Archaea that are ubiquitous in a range of natural archives and especially abundant in peat. Previous work demonstrated that the distribution of bacterial branched GDGTs (brGDGTs) in mineral soils is correlated to environmental factors such as mean annual air temperature (MAAT) and soil pH. However, the influence of these parameters on brGDGT distributions in peat is largely unknown. Here we investigate the distribution of brGDGTs in 470 samples from 96 peatlands around the world with a broad mean annual air temperature (−8 to 27 °C) and pH (3–8) range and present the first peat-specific brGDGT-based temperature and pH calibrations. Our results demonstrate that the degree of cyclisation of brGDGTs in peat is positively correlated with pH, pH = 2.49 x CBTpeat + 8.07 (n = 51, R2 65 = 0.58, RMSE = 0.8) and the degree of methylation of brGDGTs is positively correlated with MAAT, MAATpeat (°C) = 52.18 x MBT5me’ – 23.05 (n = 96, R2 67 = 0.76, RMSE = 4.7 °C). 3 These peat-specific calibrations are distinct from the available mineral soil calibrations. In light of the error in the temperature calibration (~ 4.7 °C), we urge caution in any application to reconstruct late Holocene climate variability, where the climatic signals are relatively small, and the duration of excursions could be brief. Instead, these proxies are well-suited to reconstruct large amplitude, longer-term shifts in climate such as deglacial transitions. Indeed, when applied to a peat deposit spanning the late glacial period (~15.2 kyr), we demonstrate that MAATpeat yields absolute temperatures and relative temperature changes that are consistent with those from other proxies. In addition, the application of MAATpeat to fossil peat (i.e. lignites) has the potential to reconstruct terrestrial climate during the Cenozoic. We conclude that there is clear potential to use brGDGTs in peats and lignites to reconstruct past terrestrial climateThis research was funded through the advanced ERC grant “the greenhouse earth system” (T-GRES, project reference 340923), awarded to RDP. All authors are part of the “T-GRES Peat Database collaborators” collective. RDP also acknowledges the Royal Society Wolfson Research Merit Award. We thank D. Atkinson for help with the sample preparation. We acknowledge support from Labex VOLTAIRE (ANR-10- 22 LABX-100-01). Peat from Patagonia and Tierra del Fuego were collected thanks to a Young Researcher Grant of the Agence National de la Recherche (ANR) to FDV, project ANR-2011-JS56-006-01 “PARAD” and with the help of Ramiro Lopez, Andrea Coronato and Veronica Pancotto (CADIC-CONICET, Ushuaia). Peat from Brazil was collected with the context of CNPq project 482815/2011-6. Samples from France (Frasne and La Guette) were collected thanks to the French Observatory of Peatlands. The Canadian peat was collected in the context of the NSERC-Discovery grant of L. Rochefort. Peats from China were obtained under a National Natural Science Foundation of China grant (No. 41372033), awarded to Y. Zheng

Introducing global peat-specific temperature and pH calibrations based on brGDGT bacterial lipids

Glycerol dialkyl glycerol tetraethers (GDGTs) are membrane-spanning lipids from Bacteria and Archaea that are ubiquitous in a range of natural archives and especially abundant in peat. Previous work demonstrated that the distribution of bacterial branched GDGTs (brGDGTs) in mineral soils is correlated to environmental factors such as mean annual air temperature (MAAT) and soil pH. However, the influence of these parameters on brGDGT distributions in peat is largely unknown. Here we investigate the distribution of brGDGTs in 470 samples from 96 peatlands around the world with a broad mean annual air temperature (-8 to 27 degrees C) and pH (3-8) range and present the first peat-specific brGDGT-based temperature and pH calibrations. Our results demonstrate that the degree of cyclisation of brGDGTs in peat is positively correlated with pH, pH = 2.49 x CBTpeat + 8.07 (n = 51, R-2 = 0.58, RMSE = 0.8) and the degree of methylation of brGDGTs is positively correlated with MAAT, MAAT(peat) (degrees C) = 52.18 x MBT'(5me) - 23.05 (n = 96, R-2 = 0.76, RMSE = 4.7 degrees C). These peat-specific calibrations are distinct from the available mineral soil calibrations. In light of the error in the temperature calibration (similar to 4.7 degrees C), we urge caution in any application to reconstruct late Holocene climate variability, where the climatic signals are relatively small, and the duration of excursions could be brief. Instead, these proxies are well-suited to reconstruct large amplitude, longer-term shifts in climate such as deglacial transitions. Indeed, when applied to a peat deposit spanning the late glacial period (similar to 15.2 kyr), we demonstrate that MAAT(peat) yields absolute temperatures and relative temperature changes that are consistent with those from other proxies. In addition, the application of MAAT(peat) to fossil peat (i.e. lignites) has the potential to reconstruct terrestrial climate during the Cenozoic. We conclude that there is clear potential to use brGDGTs in peats and lignites to reconstruct past terrestrial climate. (C) 2017 The Authors. Published by Elsevier Ltd

C mobilisation in disturbed tropical peat swamps: old DOC can fuel the fluvial efflux of old carbon dioxide, but site recovery can occur

Southeast-Asian peat swamp forests have been significantly logged and converted to plantation. Recently, to mitigate land degradation and C losses, some areas have been left to regenerate. Understanding how such complex land use change affects greenhouse gas emissions is essential for modelling climate feedbacks and supporting land management decisions. We carried out field research in a Malaysian swamp forest and an oil palm plantation to understand how clear-felling, drainage, and illegal and authorized conversion to oil palm impacted the C cycle, and how the C cycle may change if such logging and conversion stopped. We found that both the swamp forest and the plantation emit centuries-old CO2 from their drainage systems in the managed areas, releasing sequestered C to the atmosphere. Oil palm plantations are an iconic symbol of tropical peatland degradation, but CO2 efflux from the recently-burnt, cleared swamp forest was as old as from the oil palm plantation. However, in the swamp forest site, where logging had ceased approximately 30 years ago, the age of the CO2 efflux was modern, indicating recovery of the system can occur. 14C dating of the C pool acted as a tracer of recovery as well as degradation and offers a new tool to assess efficacy of restoration management. Methane was present in many sites, and in higher concentrations in slow-flowing anoxic systems as degassing mechanisms are not strong. Methane loading in freshwaters is rarely considered, but this may be an important C pool in restored drainage channels and should be considered in C budgets and losses

The emergence of regional security organisations. A comparative study on ECOWAS and SADC.

The emergence of regional security organisations during the 1990s in Africa proved to be of great significance for the lives of many Africans, including those living in conflict-torn countries such as Liberia, Sierra Leone, Côte d’Ivoire or the Democratic Republic of Congo, but, at the same time, this phenomenon has been understudied. This dissertation explores why regional security organisations with an agenda of democratic governance emerged in Africa in the 1990s. This question is answered with two in-depth case studies on the Economic Community of West African States (ECOWAS) and the Southern African Development Community (SADC). Driven by an empirical puzzle, this study is both hypothesis-testing and hypothesis generating. The study starts by laying out the different possible factors put forward by several bodies of theory in international relations to explain the emergence of ECOWAS and SADC as security organisations. These hypotheses are then tested throughout the history and the evolution of ECOWAS and SADC in order to highlight the circumstances of their creation and their qualified failure as economic communities. This is followed by a comparative analysis of the security and democracy mandates entrusted to ECOWAS and SADC by its member states based on the study of the legal texts that outline the specific objectives of each regional security organisation and the tools they were given to implement their mandates. The study finally analyses the implementation records of ECOWAS and SADC in order to assess the commitment of their member states to their new democracy and security mandate. The research concludes with the two following hypotheses: 1) A security agenda cannot emerge without the involvement of the regional hegemon. 2) What the regional hegemon can do, including affecting the speed of the transformation, is constrained by the acceptance of its leadership by its neighbours (legitimacy) and by state weakness (capability)

The emergence of regional security organisations. A comparative study on ECOWAS and SADC.

The emergence of regional security organisations during the 1990s in Africa proved to be of great significance for the lives of many Africans, including those living in conflict-torn countries such as Liberia, Sierra Leone, Côte d’Ivoire or the Democratic Republic of Congo, but, at the same time, this phenomenon has been understudied. This dissertation explores why regional security organisations with an agenda of democratic governance emerged in Africa in the 1990s. This question is answered with two in-depth case studies on the Economic Community of West African States (ECOWAS) and the Southern African Development Community (SADC). Driven by an empirical puzzle, this study is both hypothesis-testing and hypothesis generating. The study starts by laying out the different possible factors put forward by several bodies of theory in international relations to explain the emergence of ECOWAS and SADC as security organisations. These hypotheses are then tested throughout the history and the evolution of ECOWAS and SADC in order to highlight the circumstances of their creation and their qualified failure as economic communities. This is followed by a comparative analysis of the security and democracy mandates entrusted to ECOWAS and SADC by its member states based on the study of the legal texts that outline the specific objectives of each regional security organisation and the tools they were given to implement their mandates. The study finally analyses the implementation records of ECOWAS and SADC in order to assess the commitment of their member states to their new democracy and security mandate. The research concludes with the two following hypotheses: 1) A security agenda cannot emerge without the involvement of the regional hegemon. 2) What the regional hegemon can do, including affecting the speed of the transformation, is constrained by the acceptance of its leadership by its neighbours (legitimacy) and by state weakness (capability).N.B. Only the abstract and table of contents of this thesis are currently available in ORA

La technologie de la réduction en vase-four, en contexte campaniforme sur la façade atlantique française, mise en évidence par les analyses p-XRF couplées à l’observation pétrologique

International audienceLa technologie de la réduction en vase-four, en contexte campaniforme sur la façade atlantique française, mise en évidence par les analyses p-XRF couplées à l'observation pétrologique En France, les éléments permettant de mettre en évidence des travaux métallurgiques sur les sites datant du Campaniforme sont extrêmement rares, et correspondent à des résidus cuivreux, collés ou non à des céramiques, sous forme de nodules voire de scorie. Le site de Talmont Saint Hilaire (Vendée) fouillé à nouveau en 2014, après les opérations de 1988 et 1990 qui avaient permis la découverte de résidus cuivreux, a livré un fragment de céramique commune présentant un résidu cuivreux sur la face interne. Les analyses au MEB-EDS sur les billes de métal emprisonnées ont montré la présence d'un métal hétérogène, en cuivre quasiment pur ou allié avec As (1.5 à 40.4%), Ni (1.8 à 32%), Sb (1.5 à 2.5 %) et Fe (0.5 à 4.2 %). L'analyse par p-XRF a de plus montré la présence du soufre indiquant l'introduction de la matière première sous forme de minerai dans le vase-four qui correspond à une céramique commune, et un enrichissement en phosphore indiquant la présence de charbon. La céramique autour du résidu cuivreux présente un aspect poreux ou presque vitrifié, indiquant une chauffe à haute température. L'analyse par p-XRF, d'autres fragments de céramiques, sans résidu cuivreux mais plus ou moins dégradées sur la face interne, a montré la présence nette du cuivre (406 à 1319 ppm) et de l'arsenic (157 à 257 ppm), éléments absents de la pâte céramique intacte. Ces tessons correspondent à de la céramique commune réemployée en métallurgie. Hors secteurs miniers de production, cette métallurgie a pu être mise en oeuvre en contexte domestique. Sans trace évidente de résidus cuivreux, elle passe alors totalement inaperçue. Ainsi, cette première métallurgie, considérée comme très rare en France, pourrait être plus présente que la connaissance que nous avons actuellement. L'analyse par p-XRF de nombreux tessons de céramiques communes campaniformes permettra ainsi de mieux en évaluer l'ampleur

Évaluation de la pollution par les microplastiques du compartiment atmosphérique et des systèmes fluviaux pyrénéens

International audiencePlastic pollution is a worldwide environmental issue, which affects all natural habitats, even in the most pristine areas. Recent workssuggest that rivers may act as temporary sinks for land-based plastic pollution while also serving as transport “highways” for plastic waste tothe ocean. Until now though, studies on airborne microplastics (MPs) have mainly been focused on urban areas, with much less attentiongiven towards remote and pristine systems. Further, studies have also stated that atmospheric circulation is responsible for the re-emissionand return of MP particles from marine environments back to terrestrial habitats. Here, we present the results derived from the cooperationbetween the PLASTICØPYR and ATMO-PLASTIC projects, both focused on the impact of plastic pollution in the Pyrenees under differentlevels of human activity. The PLASTICØPYR and ATMO-PLASTIC projects aim to quantify MPs in different river habitats and the emission ofMPs to the atmospheric compartment, respectively. Both projects aim to illustrate that MP pollution is not restricted uniquely to urban sites.The main goal of this collaboration is to acquire a holistic understanding of the link between human activity and plastic pollution in fluvialsystems and the atmospheric compartment, in order to identify the main sources of MP pollution in pristine areas of the Pyrenees, includingthe site of Bernadouze OHM Vicdessos. Our results will allow us to identify the most impacted areas, and potential MP pollution hotspots,which in turn will further our understanding of plastic dynamics between rivers and the atmosphere.La pollution plastique est un problème environnemental mondial, qui affecte tous les habitats naturels, même les plus vierges. Desétudes récentes suggèrent que les rivières peuvent fonctionner comme des puits temporaires pour la pollution plastique terrestre et commeune voie d'entrée des déchets plastiques dans l'océan, cependant l’accumulation en milieu marin n'est peut-être pas la destination finale desparticules microplastiques. Les études sur les microplastiques (MPs) en suspension dans l'air se sont principalement centrées sur les zonesurbaines. D’autres études indiquent que la circulation atmosphérique est responsable du refoulement des particules de MPs des habitatsmarins vers les habitats terrestres. Le présent poster est le fruit de la collaboration des projets PLASTICØPYR et ATMO-PLASTIC, tousdeux axés sur l'impact de la pollution plastique dans les Pyrénées en relation avec différents niveaux d'activité humaine. L’objectif des projetsPLASTICØPYR et ATMO-PLASTIC est de quantifier les MPs dans différents habitats fluviaux et l'émission de MPs dans le compartimentatmosphérique, respectivement. Les deux projets visent à illustrer le fait que la pollution par les MPs n'est pas limitée uniquement aux sitesurbains. L'objectif principal de cette collaboration est d'acquérir une compréhension globale du lien entre l'activité humaine et la pollutionplastique dans les systèmes fluviaux et le compartiment atmosphérique, afin d'identifier les principales sources de pollution par les MPs dansdes zones vierges telles que les Pyrénées dont le site de Bernadouze OHM Vicdessos. Nos résultats nous permettront d'identifier les zonesles plus impactées et de comprendre la dynamique du plastique entre les rivières et l'atmosphère