Suelos de Gipuzkoa sobre argilitas : factores limitantes a su uso y conservación

En este estudio se caracterizan las propiedades de los suelos de Gipuzkoa desarrollados sobre argilitas y se evalúan en función de las limitaciones que presentan para su uso y conservación, por medio del Soil Fertility Capability Classification System de Buol (1972). Las principales características de estos suelos son su textura limosa a arcillosa, alta densidad aparente, contenidos bajos a moderados de materia orgánica, reacción ácida, déficit importante de nutrientes y elevada saturación de aluminio en el complejo de intercambio, además de situarse en áreas de topografía colinada. Estas propiedades hacen que sean muy susceptibles a la erosión y tengan problemas considerables para la nutrición de las plantas y toxicidad potencial por aluminioLan honetan Gipuzkoan argiliten gainean moldaturiko lurzoruen ezaugarriak aztertzen dira eta beraien erabilpen eta kontserbaziorako aurkezten dituzten mugak ebaluatzen dira, Buol-en Soil Fertility Capability Classification System delakoaren bidez (1972). Lurzoru hauen ezaugarri nagusiak: limo eta buztinaren arteko egitura, materia organikoen kopuru txiki edo moderatuak, erreakzio azidoa, nutrienteen eskasia nabarmena eta aluminio-saturazio handia elkartrukearen konplexuan, muino-topografia duten lekuetan kokatuak izateaz gain. Ezaugarri horiek direla eta, higaduraren menpe daude, landareen nutriziorako arazo handiak dituzte eta aluminiozko toxizitate potentzial handia duteDans la présente étude nous signalons les caractéristiques des sols de Gipuzkoa développés sur des argilites et nous les évaluons en fonction des limitationes qu'ils présentent du point de vue de leur utilisation et de leur conservation, en utilisant le Soil Fertility Capability Classification System de Buol (1972). Les principales caractéristiques de ces sols sont leur texture de limoneuse à argileuse, leur haute densité apparente, leurs contenus de bas à modérés de matière organique, leur réaction acide, leur déficit important en matiéres nourricières et leur importante saturation en aluminium dans le complexe d'échange, et également le fait qu'ils se trouvent dans des zones d'une topographie de collines. Ces caractéristiques les rendent très sensibles à l'érosion et posent des problèms considérables du point de vue de l'alimentation des plantes et de la toxicité potentielle par aluminiu

Cerámica campaniforme de Galicia (NW de España): Caracterización arqueométrica y estudio de procedencia de algunos yacimientos representativos

Se describen los resultados del estudio arqueométrico (composición mineral y elemental) de 55 muestras de recipientes campaniformes recuperadas en 8 yacimientos arqueológicos del NW de la Península Ibérica. Las muestras son representativas de la variación formal de la cerámica (tanto lisa como decorada) y del tipo de contextos (ceremonial, doméstico y funerario) donde las cerámicas campaniformes fueron encontradas en la región. Las composiciones mineral y elemental mostraron un alto grado de coherencia. La mayor parte de los recipientes tenía composiciones con proporciones variables de feldespato potásico y plagioclasa, o de plagioclasa y anfíbol, coherentes con la litología local. También se encontraron composiciones mezcla de feldespato potásico y anfíbol, que no se encuentran de forma natural en los materiales geológicos del entorno, lo que apunta a una mezcla intencional de materias primas. La cerámica campaniforme, comparada con la de otros períodos previos, muestra fuertes cambios en relación con el estilo, pero mantiene una continuidad en cuanto al uso de los recursos de materia prima. No se encontró relación entre aspectos formales y la composición de la cerámica. La mayor parte de la cerámica estudiada procede probablemente del entorno de los yacimientos. Un análisis de distancias a las áreas potenciales para los materiales, empleando un sistema de información geográfica, sugiere que prácticamente todas pueden encontrarse en un radio de 16 km (la mayoría entre 2 y 5 km), lo que implica una a dos horas. Parece que el esfuerzo asociado a las cerámicas de contextos ceremoniales fue mayor que el de la cerámica de contextos funerarios y de asentamientoWe describe the results of an archaeometric study (mineral and elemental composition) of 55 samples from Bell Beaker vessels recovered from 8 archaeological sites in the northwest of the Iberian Peninsula. The samples are representative of the formal variation of the pottery (both decorated and undecorated) and type of contexts (ceremonial, domestic and funerary) in which Bell Beaker pottery is found in the region. Both, mineral and elemental composition were found to be highly consistent. Most of the vessels had compositions resulting from mixtures of potassium feldspar and plagioclase or plagioclase and amphibole, which are coherent with the local lithology. A few pottery samples showed a mixed composition of potassium feldspar and amphibole, which is not found naturally in the surrounding geological materials, indicating an intentional mixing of different raw materials. Compared to previous periods, Bell Beaker pottery represented a significant change in terms of style but continuity in terms of the use of raw materials. No relationship was found between the formal aspects and the composition of the pottery. Most of the samples we studied were probably manufactured with materials obtained from the area around the sites. An analysis of distances to potential source areas for the materials, using a geographical information system, indicates that almost all can be found within a radius of 16 km (most between 2-5 km), implying between one and two hours walk. A greater effort seems to have been associated to pottery of ceremonial sites compared to funerary and settlement sites

Reconstructing the impact of human activities in a NW Iberian Roman mining landscape for the last 2500 years

This article was made available through the Brunel Open Access Publishing Fund.Little is known about the impact of human activities during Roman times on NW Iberian mining landscapes beyond the geomorphological transformations brought about by the use of hydraulic power for gold extraction. We present the high-resolution pollen record of La Molina mire, located in an area intensely used for gold mining (Asturias, NW Spain), combined with other proxy data from the same peat core to identify different human activities, evaluate the strategies followed for the management of the resources and describe the landscape response to human disturbances. We reconstructed the timing and synchronicity of landscape changes of varying intensity and form occurred before, during and after Roman times. An open landscape was prevalent during the local Late Iron Age, a period of relatively environmental stability. During the Early Roman Empire more significant vegetation shifts took place, reflected by changes in both forest (Corylus and Quercus) and heathland cover, as mining/metallurgy peaked and grazing and cultivation increased. In the Late Roman Empire, the influence of mining/metallurgy on landscape change started to disappear. This decoupling was further consolidated in the Germanic period (i.e., Visigothic and Sueve domination of the region), with a sharp decrease in mining/metallurgy but continued grazing. Although human impact was intense in some periods, mostly during the Early Roman Empire, forest regeneration occurred afterwards: clearances were local and short-lived. However, the Roman mining landscape turned into an agrarian one at the onset of the Middle Ages, characterized by a profound deforestation at a regional level due to a myriad of human activities that resulted in an irreversible openness of the landscape. © 2014 The Authors

Influence of climate change and human activities on the organic and inorganic composition of peat during the ‘Little Ice Age’ (El Payo mire, W Spain)

Acknowledgements We are grateful to Ana Moreno, Mariano Barriendos and Gerardo Benito who kindly provided us data included in Figure 5a. We also want to thank the two anonymous reviewers for their constructive comments. Funding This work was funded by the projects HAR2013-43701-P (Spanish Economy and Competitiveness Ministry) and CGL2010-20672 (Spanish Ministry of Science and Innovation). This research was also partially developed with Xunta de Galicia funding (grants R2014/001 and GPC2014/009). N Silva-Sánchez is currently supported by an FPU pre-doctoral grant (AP2010-3264) funded by the Spanish Government.Peer reviewedPostprin

Lake and crannog : A 2500-year palaeoenvironmental record of continuity and change in NE Scotland

Acknowledgements Special acknowledgements go to Audrey Innes for her laboratory support, to Laura McHardie who originally extracted the core with Michael J. Stratigos. Thanks are owed to the Leys Estate and the then Estate Manager Thys Simpson for allowing access, help in taking the core and overall support for work in the former loch. Thanks to the Hunter Archaeological and Historical Trust who funded the fieldwork. The article was written as part of the Leverhulme Trust funded project ‘Comparative Kingship: the early Medieval kingdoms of Northern Britain and Ireland’ (Grant RG13876-10). Authors would like to thank the use of RIAIDT-USC analytical facilities. OLC is funded by JIN project (PID2019-111683RJ-I00) Spanish Ministerio de Ciencia e Innovacion and Beca Leonardo a Investigadores y Creadores Culturales 2020 de la Fundación BBVA. open access via Elsevier agreementPeer reviewedPublisher PD

Factors controlling the geochemical composition of Limnopolar Lake sediments (Byers Peninsula, Livingston Island, South Shetland Island, Antarctica) during the last ca. 1600 years

We sampled a short (57 cm) sediment core in Limnopolar Lake (Byers Peninsula, Livingston Island, South Shetland Islands), which spans the last ca. 1600 years. The core was sectioned at high resolution and analyzed for elemental and mineralogical composition, and scanning electron microscope and energy dispersive X-ray spectrometer (SEM-EDS) analysis of glass mineral particles in selected samples. The chemical record was characterized by a contrasted pattern of layers with high Ca, Ti, Zr, and Sr concentrations and layers with higher concentrations of K and Rb. The former were also enriched in plagioclase and, occasionally, in zeolites, while the latter were relatively enriched in 2 : 1 phyllosilicates and quartz. This was interpreted as reflecting the abundance of volcaniclastic material (Ca rich) versus Jurassic–Lower Cretaceous marine sediments (K rich) – the dominant geological material in the lake catchment. SEM-EDS analysis revealed the presence of abundant volcanic shards in the Ca-rich layers, pointing to tephras most probably related to the activity of Deception Island volcano (located 30 km to the SE). The ages of four main peaks of volcanic-rich material (AD ca. 1840–1860 for L1, AD ca. 1570–1650 for L2, AD ca. 1450–1470 for L3, and AD ca. 1300 for L4) matched reasonably well the age of tephra layers (AP1 to AP3) previously identified in lakes of Byers Peninsula. Some of the analyzed metals (Fe, Mn, Cu, and Cr) showed enrichments in the most recent tephra layer (L1), suggesting relative changes in the composition of the tephras as found in previous investigations. No evidence of significant human impact on the cycles of most trace metals (Cu, Zn, Pb) was found, probably due to the remote location of Livingston Island and the modest research infrastructures; local contamination was found by other researchers in soils, waters and marine sediments on areas with large, permanent research stations. Chromium is the only metal showing a steady enrichment in the last 200 years, but this cannot be directly attributed to anthropogenic pollution since recent research supports the interpretation that climatic variability (reduced moisture content and increased wind intensity) may have resulted in enhanced fluxes of mineral dust and trace elements (Cr among them) to Antarctica. At the same time, some features of the chemical record suggest that climate may have also played a role in the cycling of the elements, but further research is needed to identify the underlying mechanisms.This work was partially supported by projects CGL2010-20672 and REN2000-0345-ANT (Spanish Ministerio de Ciencia e Innovación), POL2006-06635/CGL (Spanish Ministerio de Educación y Cultura), and 10PXIB200182PR (Dirección Xeral de I+D, Xunta de Galicia).Peer reviewe

Holocene atmospheric dust deposition in NW Spain

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.Atmospheric dust plays an important role in terrestrial and marine ecosystems, particularly those that are nutrient limited. Despite that most dust originates from arid and semi-arid regions, recent research has shown that past dust events may have been involved in boosting productivity in nutrient-poor peatlands. We investigated dust deposition in a mid-latitude, raised bog, which is surrounded by a complex geology (paragneiss/schist, granite, quartzite and granodiorite). As proxies for dust fluxes, we used accumulation rates of trace (Ti, Zr, Rb, Sr and Y) as well as major (K and Ca) lithogenic elements. The oldest, largest dust deposition event occurred between ~8.6 and ~7.4 ka BP, peaking at ~8.1 ka BP (most probably the 8.2 ka BP event). The event had a large impact on the evolution of the mire, which subsequently transitioned from a fen into a raised bog in ~1500 years. From ~6.7 to ~4.0 ka BP, fluxes were very low, coeval with mid-Holocene forest stability and maximum extent. In the late Holocene, after ~4.0 ka BP, dust events became more prevalent with relatively major deposition at ~3.2–2.5, ~1.4 ka BP and ~0.35–0.05 ka BP, and minor peaks at ~4.0–3.7, ~1.7, ~1.10–0.95 ka BP and ~0.74–0.58 ka BP. Strontium fluxes display a similar pattern between ~11 and ~6.7 ka BP but then became decoupled from the other elements from the mid Holocene onwards. This seems to be a specific signal of the granodiorite batholith, which has an Sr anomaly. The reconstructed variations in dust fluxes bear a strong climatic imprint, probably related to storminess controlled by North Atlantic Oscillation conditions. Complex interactions also arise because of increased pressure from human activities.Natural Environment Research Council (NERC)Consiliencia networkFunding for Consolidation and Structuration of Research Unit

Preferential degradation of polyphenols from Sphagnum - 4-isopropenylphenol as a proxy for past hydrological conditions in Sphagnum-dominated peat

The net accumulation of remains of Sphagnum spp. is fundamental to the development of many peatlands. The effect of polyphenols from Sphagnum on decomposition processes is frequently cited but has barely been studied. The central area of the Rödmossamyran peatland (Sweden) is an open lawn that consists mostly of Sphagnum spp. with a very low contribution from vascular plants. In order to determine the effects of decay on sphagnum phenols, 53 samples of a 2.7 m deep core from this lawn were analysed with pyrolysis gas chromatography-mass spectrometry (pyrolysis-GC/MS) and compared with more traditional decomposition proxies such as C/N ratio, UV light transmission of alkaline peat extracts, and bulk density. Factor Analysis of 72 quantified pyrolysis products suggested that the variation in 4-isopropenylphenol was largely determined by aerobic decomposition instead of Sphagnum abundance. In order to evaluate the effects of aerobic decay in Sphagnum peat, down-core records from different climatic regions were compared using molecular markers for plant biopolymers and C/N ratio. These included markers for lignin from vascular plants ((di)methoxyphenols), polyphenols from Sphagnum spp. (4-isopropenylphenol), and cellulose (levoglucosan). Our results indicate that polyphenols from Sphagnum are preferentially degraded over polysaccharides; consequently the variability of the marker for sphagnum acid, 4-isopropenylphenol, was found indicative of decomposition instead of reflecting the abundance of Sphagnum remains. The fact that 4-isopropenylphenol is aerobically degraded in combination with its specificity for Sphagnum spp. makes it a consistent indicator of past hydrological conditions in Sphagnum-dominated peat. In contrast, the variability of C/N records in Sphagnum-dominated peat was influenced by both vegetation shifts and decomposition, and the dominant effect differed between the studied peatlands. Our results provide direction for modelling studies that try to predict possible feedback mechanisms between peatlands and future climate change, and indicate that the focus in Sphagnum decay studies should be on carbohydrates rather than on phenolic compounds

Linking forest cover, soil erosion and mire hydrology to late-Holocene human activity and climate in NW Spain

This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 License (http://www.creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (http://www.uk.sagepub.com/aboutus/openaccess.htm).This article has been made available through the Brunel Open Access Publishing Fund.Forest clearance is one of the main drivers of soil erosion and hydrological changes in mires, although climate may also play a significant role. Because of the wide range of factors involved, understanding these complex links requires long-term multi-proxy approaches and research on the best proxies to focus. A peat core from NW Spain (Cruz do Bocelo mire), spanning the last ~3000 years, has been studied at high resolution by physical (density and loss on ignition (LOI)), geochemical (elemental composition) and palynological (pollen and non-pollen palynomorphs) analyses. Proxies related to mineral matter fluxes from the catchment (lithogenic tracers, Glomus and Entorrhiza), rainfall (Bromine), mire hydrology (HdV-18), human pressure (Cerealia-type, nitrophilous taxa and coprophilous fungi) and forest cover (mesophilous tree taxa) were the most useful to reconstruct the evolution of the mire and its catchment. Forest clearance for farming was one of the main drivers of environmental change from at least the local Iron Age (~2685 cal. yr BP) onwards. The most intense phase of deforestation occurred during Roman and Germanic times and the late Middle Ages. During these phases, the entire catchment was affected, resulting in enhanced soil erosion and severe hydrological modifications of the mire. Climate, especially rainfall, may have also accelerated these processes during wetter periods. However, it is noteworthy that the hydrology of the mire seems to have been insensitive to rainfall variations when mesophilous forest dominated. Abrupt changes were only detected once intense forest clearance commenced during the Iron Age/Roman transition (~2190 cal. yr BP) phase, which represented a tipping point in catchment's ability to buffer impacts. Overall, our findings highlight the importance of studying ecosystems' long-term trajectories and catchment-wide processes when implementing mire habitat protection measures.This work was funded by the projects CGL2010-20672 (Plan Nacional I+D+i, Spanish Ministry of Science and Innovation) and 10PXIB200182PR (General Directorate of I+D, Xunta de Galicia). N Silva-Sánchez and L López-Merino are currently supported by a FPU predoctoral scholarship (AP2010-3264) funded by the Spanish Government and a MINT postdoctoral fellowship funded by the Brunel Institute for the Environment, respectively