14 research outputs found
Persistence of tree relicts in the Spanish Central System through the Holocene
Persistence of relict tree species in Mediterranean environments is becoming increasingly unlikely in view of ongoing and future global change. The variability in the Holocene climate and more recent anthropogenic impacts have driven many populations to fragmentation and isolation, and even to extinction. However, some have persisted to the present day. The understanding of their evolution requires long-term studies, in which pollen analysis is a key approach both for formulating hypotheses and supporting results from other disciplines. Mountain ranges have played and still play an essential role as both glacial and interglacial refugia during the Quaternary. The Spanish Central System harbors an exceptional diversity due to its geographical location and complex topography. Some cold-adapted species have survived here with significant proportions of their southernmost populations, often displaying striking adaptations to their changing environments. This work contains a comprehensive review of the palynological investigations conducted in the Spanish Central System, and reveals the distribution of genera such as Taxus, Betula, Fagus, Carpinus and Tilia throughout the Holocene. We also highlight the scarcity of well-dated and high-resolution works, which may contribute to a better understanding of their recent and future evolution.This paper is part of the research carried our within the
project "Dinámicas socio-ecológicas, resiliencia y vulnerabilidad
en un paisaje de montaña: el Sistema Central (9000
cal. BC-1850 cal. AD) " (R&D National Plan of the Spanish
Government, HAR2013-43701-P)
Restos de caballos fósiles cuaternarios en la depresión Prados-Guatén (Pantoja de la Sagra, Toledo)
Durante la primera reunión de campo del Grupo Madrileño de Cuaternario (GQM-AEQUA) se localizaron restos fragmentarios de dentición de caballos fósiles en los antiguos areneros de Pantoja de La Sagra (Toledo), actualmente en proceso de desmantelamiento y relleno. Ante la posibilidad de deterioro y pérdida los restos fueron recolectados y trasladados al Museo Nacional de Ciencias Naturales (CSIC, Madrid) donde se ha procedido a su análisis. Las piezas fósiles analizadas responden a un maxilar izquierdo con tres piezas dentales in situ (molares y premolares), y otras siete más aisladas. Todos los dientes aislados, junto con el fragmento de maxilar existente, corresponden a un adulto joven. Los restos fósiles se encontraban asociados a un nivel de arenas fluviales situado unos cuatro metros por debajo de la superficie de la Terraza de +15 m de la Depresión Prados-Guatén definida como un nivel perteneciente al tránsito Pleistoceno inferior-medio, del antiguo Sistema fluvial Manzanares-Guatén por Silva (1988). En concreto los niveles superiores de esta terraza han sido interpretados como resultado de la superposición de los últimos depósitos del antiguo sistema fluvial y los primeros asociados al relleno de la Depresión por tributarios de área fuente más local tras su abandono como consecuencia del proceso de captura del valle inferior del Manzanares por parte del Río Jarama al SW de la Ciudad de Madrid (Silva et al., 1988). Los caracteres morfológicos y morfométricos de las piezas dentarias permiten identificarlos como Equus ferus cf. mosbachensis cuya distribución bioestratigráfica abarca la parte final del Pleistoceno Medio (c.a. 500-200 ka B.P.). Junto a los restos fósiles aparecieron también escasos fragmentos líticos correspondientes a productos de lascado en sílex de difícil atribución tecnológica. Los restos fósiles analizados, indican que el depósito extensivo de arenas fluviales en el eje de la Depresión, culminó durante el final del Pleistoceno medio, y que la dinámica fluvial de la Depresión tras su proceso de abandono fue de hecho más activa de lo que se pensaba con la instalación de sistemas de arroyos relevantes alimentados por cabeceras locales antes del encajamiento definitivo actual de los arroyos Prados y Guatén.Peer reviewe
26. Valdeyernos, Toledo Mountains (central Spain)
This contribution was financed by Project CGL2011-30512-C02-01 of the R&D National Plan of the Spanish Government, by the Technology Research ‘Consolider’ Programme (TCP-CSD2007-00058), and by the Specific Agreement Diputación de Toledo-CSIC
Contributions to the European Pollen Database. 21. Patateros, Toledo Mountains (central Spain)
The Patateros bog (39° 35′ 50′′ N, 4° 40′ 27′′ W; 700 m above sea level [a.s.l.]) lies on the northern-
slope of the‘
Sierra de La Botija’
at the northern edge
of the Toledo Mountains. The peat-bog extends
over an area of 300 m2. The area experiences a
Mediterranean climate with dry and warm summers,
in
fluenced by Atlantic winds from the southwest. The
average annual temperature is 14–15 °C and the
annual precipitation is 600–700 mm. Precipitation is
unevenly distributed through the year with maximum
values during winter (Perea & Perea2008). The vegetation is a planted
Pinus
forest. Phytogeographically,
the potential vegetation of the area is typically
Mediterranean, including
Quercus pyrenaica
Willd.
(deciduous oak) forests accompanied by
Arbutus
unedo
L. (Peinado et al.2008). The bog vegetation is
composed mainly of
Sphagnum sp.,
Erica tetralix L.
and
Molinia caerulea
(L.) Moench. (Velasco
1980).
The bedrock is old siliceous basement made up
mainly of lower Ordovician Armorican Quartzites
(Moreno
1977).This contribution was financed by Project CGL2011-30512-C02-01 of the R&D National Plan of the Spanish Government, by the Technology Research ‘Consolider’
Programme (TCP-CSD2007-00058), and by the Specific Agreement Diputación de Toledo-CSIC.Peer Reviewe
Middle Pleistocene variations in palaeoclimate, palaeoenvironment and vegetation of the Las Tablas de Daimiel National Park (Spain)
Received 15 August 2009; Revised 17 June 2010; Accepted 21 June 2010.
Copyright © 2011 John Wiley & Sons, Ltd.The Middle Pleistocene palaeoclimate and palaeoenvironment evolution of the Las Tablas de Daimiel wetlands is described using a combination of sedimentology, pollen and δ13C and δ18O isotopic records of Unit B of core LT-199906. This unit mostly contains fluvial and palustrine sediments. U/Th and amino acid racemization (AAR) dating and a comparison of the δ18Ocurve of Unit B with oceanic records suggests that Unit B spans the period from the end of Marine Isotope Stage (MIS) 10 (340 ka) to the first stages of MIS 7 (ca. 210 ka). MIS 9 was characterised by a regional vegetation dominated by Cupressaceae, with Pinus as a tree element. The water level was high and temperatures were very probably higher than during the Holocene. MIS 8 and the first substages of MIS 7 (7e, 7d and 7c) were dominated by xerophilous steppe vegetation in lowlands (elevations around 610m above sea level) near to the wetland. At higher altitudes, far away from the wetland, there were fewer Pinus than in MIS 9, and a greater presence of warm, temperate and cool climate tree elements. The aquatic system in MIS 9 became shallower, with eutrophication and the accumulation of organic matter occurring; temperatures were similar to or lower than those of the Holocene.Ministerio de Educación y Ciencia (España)Ministerio de Educación y Ciencia (España)Ministerio de Educación y Ciencia (España)Ministerio de Educación y Ciencia (España)Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu
Millennial climate oscillations controlled the structure and evolution of Termination II
The controls that affect the structure and timing of terminations are still poorly understood. We studied a tufa deposit from the Iberian Peninsula that covers Termination II (T-II) and whose chronology was synchronized to speleothem records. We used the same chronology to synchronize ocean sediments from the North Atlantic to correlate major climate events in a common timescale. We identify two stages within T-II. The first stage started with the increase of boreal summer integrated solar insolation, and during this stage three millennial climate oscillations were recorded. These oscillations resulted from complex ocean–atmosphere interactions in the Nordic seas, caused by the progressive decay of Northern Hemisphere ice-sheets. The second stage commenced after a glacial outburst that caused the collapse of the Thermohaline Circulation, a massive Heinrich event, and the onset of the Bipolar Seesaw Mechanism (BSM) that eventually permitted the completion of T-II. The pace of the millennial oscillations during the first stage of T-II controlled the onset of the second stage, when the termination became a non-reversible and global phenomenon that accelerated the deglaciation. During the last the two terminations, the BSM was triggered by different detailed climate interactions, which suggests the occurrence of different modes of terminations.The
Junta de Comunidades de Castilla-La Mancha provided the permissions to sample in Trabaque Canyon. Tis
research received funding from the European Community under the Marie Curie IEF of the FP7/2007-2013
(Grant agreement no. 219891: PROCAVET project, awarded to D.D.-V.). Publication was supported by the Open
Access Publication Fund of the University of Zagreb Faculty of AgriculturePeer reviewe
Landscape and climatic changes during the end of the Late Prehistory in the Amblés Valley (Ávila, central Spain), from 1200 to 400 cal BC
Correlations between ecological and cultural changes occurred during a short period between the end of Subboreal and the beginning of Subatlantic in the Amblés Valley (Ávila, central Spain) are analyzed, taking into account palaeopalynological and archaeological data. Plant dynamics from pollen analyses, both from archaeological sites and peat bogs, have been interpreted in relation to human settlements and the transformation of economic practices. These provided a comprehensive hypothesis on human/climate interactions at the beginning of the 1st millennium cal BC. There was an ecological crisis in the region that lasted for a century (ca. 850-760 cal BC). This was especially sharp due to both the geographical constraints of the area and its previous agrarian history. This event implied a sudden and abrupt climatic change from xeric and warm conditions (Subboreal) to more humid and cooler ones (Subatlantic). Environmental stress derived from climatic crisis could be an important factor in the explanation of the historical process, whose main consequences were both the origin of the Iron Age peasant villages and the end of the 'dehesa' type landscape. © 2008 Elsevier Ltd and INQUA.Peer Reviewe
Persistence of cold-adapted species through the Holocene in the Spanish Central System
Poster presentado en el 2nd International APLE-APLF Congress: "Pollen biotechnology, diversity and function in a changing environment" celebrado en Madrid del 17 al 20 de septiembre 2013Peer Reviewe