Notas corológicas sobre el Sistema Ibérico Central (provincia de Guadalajara), I

Se presentan nuevas localidades en la provincia de Guadalajara para un conjunto de 40 taxones de plantas vasculares. Entre estas caben destacar el limite meridional en el area de distribution de Erica vagans L. Se indican nuevas poblaciones de especies escasamente representadas en este tramo del Sistema Iberico, entre ellas Ranunculus ophioglossifolius Vill., Rosa villosa L., Geranium collinum Stephan ex Willd., Pulsatilla rubra Delarbre o Lathyrus pannonicus subsp. longestipulatus M. Lainz. Palabras clave: flora, plantas vasculares, corologia, Sistema Iberico, Guadalajara, Espana

Notas corológicas sobre el Sistema Ibérico (provincia de Guadalajara)II

Se presentan nuevas localidades en la provincia de Guadalajara para un conjunto de 33 táxones de plantas vasculares. Entre éstas caben destacar los primeros registros provinciales de plantas como Celtica gigantea (Link) Vázquez & Barkworth, Gagea bohemica subsp. saxatilis (Mert. & W.D.J. Koch) Asch. & Graebn., Gagea reverchonii Degen. y Peucedanum carvifolia Crantz ex Vill., novedad en la comunidad autónoma de Castilla-La Mancha. Palabras clave: flora, plantas vasculares, corología, Sistema Ibérico, Guadalajara, España

Vegetation and fire history since the last glacial maximum in an inland area of the western Mediterranean Basin (Northern Iberian Plateau, NW Spain)

We reconstructed vegetation responses to climate oscillations, fire and human activities since the last glacial maximum in inland NW Iberia, where previous paleoecological research is scarce. Extremely sparse and open vegetation composed of steppic grasslands and heathlands with scattered pioneer trees suggests very cold and dry conditions during the Oldest Dryas, unsuitable for tree survival in the surroundings of the study site. Slight woodland expansion during the Bolling/Allerod was interrupted by the Younger Dryas cooling. Pinewoods dominated for most of the early Holocene, when a marked increase in fire activity occurred. Deciduous trees expanded later reaching their maximum representation during the mid-Holocene. Enhanced fire activity and the presence of coprophilous fungi around 6400-6000 cal yr BP suggest an early human occupation around the site. However, extensive deforestation only started at 4500 calyrBP, when fire was used to clear the tree canopy. Final replacement of woodlands with heathlands, grasslands and cereal crops occurred from 2700 cal yr BP onwards due to land-use intensification. Our paleoecological record can help efforts aimed at restoring the natural vegetation by indicating which communities were dominant at the onset of heavy human impact, thus promoting the recovery of currently rare oak and alder stands

Late Holocene vegetation dynamics in response to human activities in the Teleno Mountain Range (NW Iberia)

Teleno Mountains are a good area to address these questions. Today are almost completely deforested, and it is commonly assumed that Romans were the culture responsible of this situation, as they developed important mining activities all over this mountains. Our main aim has been to track human impact on the landscape of this Iberian mountainous area along the second half of the Holocene and confirm the role of Roman culture in this process. For this purpose, we have obtained a new palaeoecological record from the Teleno Mountain

Long-term persistence of Mediterranean pine forests in the Duero Basin (central Spain) during the Holocene: The case of Pinus pinaster Aiton

In the southern Duero Basin of central Spain, there are vast areas of aeolian sand sheets and dune fields. A comprehensive survey of the sand quarries in this area identified a number of palaeosols in sedimentary sequences. The identification and AMS radiocarbon dating of soil charcoal fragments collected in these palaeosols indicate the persistence of Pinus pinaster in this area throughout most of the Holocene. Although potential natural vegetation models have usually considered the Pinus pinaster forests in this inland area of artificial origin, soil charcoal analysis provides firm evidence of a natural origin. Our data fit perfectly with the pattern of Holocene vegetation development for inland areas of Iberia, which are characterised by stability of pine forests throughout the Holocene. Finally, the growing body of palaeobotanical evidence from Iberia (macrofossils and pollen) is contributing to improve our knowledge of P. pinaster ecology, showing that this species has been present in most Iberian regions during the Holocene, where it has inhabited areas characterised by a very diverse set of climatic and soil conditions

Conservación del elemento boreo-alpino del sistema central: Microrreserva de los circos de Cerezuelo y Buitrera

El entorno del Pico del Lobo es uno de los enclaves del Sistema Central con una mayor diversidad de taxones eurosiberianos y boreo-alpinos, presentando además diversos hábitats de carácter atlántico y orófilo bien conservados. La presencia en la zona de dos especies del Catálogo de Flora Protegida regional,Swertia perennis L. y Huperzia selago (L.) Bernh. ex Schrank & Mart .subsp. selago y en el marco del Decreto 63/2007 de la Junta de Castilla y León, se propone la creación de la presente Microrreserva de Flora

The past distribution of pinus nigra arnold in northern iberia. Contribution from its macroremains.

The presence of Pinus nigra in central Spain, where its natural populations are very rare, has led to different interpretations of the current vegetation dynamics. Complementary to the available palynological evidence, macroremains provide local information of high taxonomic resolution that helps to reconstruct the palaeobiogeography of a given species. Here we present new macrofossil data from Tubilla del Lago, a small palaeolake located at the eastern part of the northern Iberian Meseta. We identified 17 wood samples and 71 cones on the basis of their wood anatomy and morphology, respectively. S ome of the fossil samples were radiocarbon dated (~4.230-3210 years cal BP). The results demonstrate the Holocene presence of P. nigra in the study area, where it is currently extinct. This evidence, together with other published palaeobotanical studies, indicates that the forests dominated by P. nigra must have had a larger importance on the landscape prior to the anthropogenic influence on the northern Iberian Meseta

Reconstructing forest history from archaeological data: A case study in the Duero basin assessing the origin of controversial forests and the loss of tree populationsof great biogeographical interest

The study of more than 700 charcoals from the Vaccaean settlement of Pintia (Padilla del Duero, Valladolid) provides new local and detailed data about the Iron Age II forest composition in Continental–Mediterranean inland Spain. Pinus gr. sylvestris/nigra (from which an unexpectedly high number of charcoals were identified), together with Mediterranean pines (also highly represented), Juniperus L. and evergreen and deciduous Quercus, were the main taxa living in the area, revealing two different marked biogeographical elements in the late-Holocene landscapes of the Duero basin: Mediterranean and Eurosiberian. On one hand, the results shed new light on the assessment of the origin of Mediterranean pinewoods in the area. On the other hand, the charcoal assemblage of Pintia reveals a more important presence of the current Mediterranean highland pines in the lowlands of the Central Iberian Peninsula in the late-Holocene suggesting the existence of interglacial refugia. Finally, this work highlights palaeoecological studies as valuable tools to support decisions on forest management related to conservation and restoration of our natural heritage

Palaeobiogeographical perspectives on pinus pinea, a controversial and enigmatic mediterranean pine

The origins of some species of economic importance occurring over the Mediterranean Basin have been a traditional matter of debate that has important implications for land management. The case of Pinus pinea L. (Stone pine) is probably one of the most controversial, due to its documented long-term interaction with humans and its presence as a symbolic tree in certain areas of the Mediterranean (e.g., southwestern Iberia and Tuscany). Among the rest of the Mediterranean pines, several features make this pine unique (it has a characteristic crown shape, an edible kernel, cones that require three years to mature, and a very depauperate genetic diversity across its range). In addition, its palaeoecological information is rather limited, as the taxonomic precision attained by pollen analysts is insufficient for this tree and macroremains (such as kernels or anatomically well preserved wood) are needed to unequivocally detect the species in the fossil record. Recent findings of macrofossils of Pinus pinea in inland Iberia (Duero Basin) extend the late- Holocene range of the species, but the palaeobiogeographical information and the exhaustive genetic data available still suggest a very limited natural area (but still not sufficiently well defined) and a long and intense history of linkage to humans

Huellas de la presencia pasada de pinares montanos en la submeseta norte de la Península Ibérica: Tubilla del Lago y Tubilla del Agua

Se presentan los resultados de los estudios de macrorrestos e impresiones vegetales hallados en dos localidades de la submeseta norte de la Península Ibérica. Los troncos y piñas subfósiles extraídos en las obras de la turbera de Tubilla del Lago (Burgos), así como el molde de piña encontrado en los travertinos de Tubilla del Agua (Burgos), han sido identificados mediante morfología comparada con apoyo de la microtomía en el caso de las maderas. Los restos subfósiles han sido datados mediante 14 C mientras que la antigüedad del molde ha sido deducida por su posición en el edificio travertínico y la edad del mismo, en base al conocimiento de la cronología de la génesis de este tipo de estructuras. Los resultados indican la presencia holocena de Pinus nigra Arnold en ambas localidades. Estas evidencias se suman a otras paleobotánicas, históricas y toponímicas ya existentes, que reflejan una mayor extensión de esta especie en la submeseta norte anterior a la generalización de la alteración antrópica del paisaj