Addicions a la brioflora del Montseny

Present work introduces thirty iwo new contributions to the bryophytic taxa from Montseny (NE Spam), in this way it extends the catalogue elaborated by Casas (1959).En aquest treball presentem trenta-dues noves aportacions a la brioflora del Montseny, i, així, ampliem el catileg elaborat per Casas (1959)

Instalación de los bosques deducida a partir del análisis polínico de un sondeo marino del Delta del Ebro (Tarragona, España)

Se ha realizado el estudio polínico de un sondeo marino situado en las costas de Tarragona. La colonización de los bosques de Quercus empezó antes de los 11000 años B.P. Un estudio comparativo de otros registros de la PenínsuIa Ibérica muestra que la colonización postglacial fue un fenómeno temporal transgresivo a Io Iargo de un gradiente latitudinal La parte inferior del dragrama, que se conespondería con el último período pleniglacial, muestra algunas fluctuaciones en los porcentajes de Quercus que se atribuyen a ligeras mejorías climáticas.PoIlen analysis from one marine core at the site of Tarragona coast (Spain) was studied. The colonisation of Quercus forest took place before 11000 years B.P. A comparative study of another records from the Iberian Peninsula confirms that the Postglacial colonisation was a temporal transgressive phenomenon along a latitudinal gradient. The lower part of the diagram, very probably corresponding to the Last Pleniglacial period, show some fluctuations in the percentages of Quercus, attributable to a slight climatic improvement

Claves para la determinación de los pólenes de las principales especies melíferas de la Península Ibérica

This paper presents keys for the identification of 216 plant taxa and pollent types from species known to be melliferous, from other honeydew-producing plants, and from companion and contaminant species.Las claves del presente articulo incluyen 216 taxones vegetales y tipos polinicos de especies meliferas ibéricas, asi como de plantas que producen mielatos y de especies que aparecen como acompañantes y contaminantes en 10s analisis de las mieles

Vestigis florístics postglacials a les Illes Balears i dinàmica de la vegetació holocènica

S'ha procedit a una inventariació d'espècies presents actualment a les Balears i que serien pròpies d'ambients mesòfils o bé que es correspondrien, des del punt de vista cronològic, amb les condicions climàtiques de la primera meitat de l'Holocè. Es reconeixen tres tipus principals d'àrees de refugi per a aquestes espècies. Paral·lelament s'ha relacionat la presència d'aquests elements amb els registres pol·línics de diferents localitats de les Balears que s'estenen principalment dins un espai temporal postglacial. Es discuteix la naturalesa i les possibles causes del canvi del paisatge vegetal vers els 5000-6000 anys BP on, de forma sobtada, les formacions de Corylus i Buxus donen pas a formacions de caràcter més xèric amb Olea.An inventory of the present Balearic plants that correspond to mesophil environments, or those with climatic conditions chronologically similar to that of the first half of the Holocene, has been done. Three main refuge areas are recognized for these species. The presence of these floristic elements has been related with the pollen register of different localities of the Balearic Islands, which extend mainly into the postglacial time. We discuss the nature and the possible causes of the vegetation landscape change that occurred towards 5000-6000 years BP, where Corylus and Buxus formations were replaced by more xeric formations with Olea

Primeres dades sobre la vegetació i el clima del Quaternari mitjà a Olot

Se presentan los resultados de análisis polínicos de sedimentos obtenidos durante la realización de un pozo industrial en la zona de la Vall d'en Bas (Olot, Cataluña, NE de España). El interés del-presente estudio se centra en las muestras de sedimentos más profundos. La deposición de estos sedimentos empezó hace unos 250.000 años como consecuencia de la obstrucción del río Fluviá por la lava procedente de los volcanes de la zona de BatetThis article presents the results of pollinic analyses carried out on samples obtained during the drilling of a well in the area of the Vail d'en Bas (Olot, Catalonia, north-eastern Spain). The deepest samples provide the most interesting findings of the study. These sediments began to be deposited some 250.000 years ago as a result of the blocking of the Fluviá river by lava from the volcanoes in the Batet area

Canvis en el paisatge vegetal de les Illes Balears durant el final del Quaternari

A partir dels coneixements actuals es conclou que l'última glaciació i l'actual període postglacial ha tingut un caràcter distintiu a les Balears en el que concerneix a l'evolució del paisatge vegetal, sobretot tenint en compte altres zones properes de l'Europa occidental. Durant el Worm han existit períodes interestadials amb expansió de les comunitats forestals de caducifolis i termòfils i, sens dubte han romàs a alguna part de les Balears refugiats. Durant l'holocé inferior les illes Balears posseïen un paisatge vegetal amb Corylus, Buxus (que tindria el màxim protagonisme en el paisatge), Juniperus, Betula i Acer. L'Holocé superior es representat, a les Illes Balears, per un paisatge dominat per l'esclerofilia en el qual Olea te una gran importància en el paisatge.The present day knowledge allows to conclude that the landscape evolution during the last glacial period and the current postglacial period in the Balearic Islands have a distinctive character, in comparison with other zones from western Europe. During the WOrm, abundant interstadials periods with important expansions of deciduous trees and termophilous vegetation have been detected. These formations have remained in different refuge areas of the Balearic Islands. During the early Holocene, the Balearic Islands possessed a plant landscape made up by Corylus, Buxus (probably the most important taxon of the landscape), Juniperus, Betula and Acer. The latter Holocene in the Balearic Islands, is represented by a landscape dominated by the sclerophillous plants, with a great importance of Olea

Landscape dynamics and fire regime since 17,550 cal yr BP in the Cantabrian region (La Molina peat bog, Puente Viesgo, Spain)

Altres ajuts: Acord transformatiu CRUE-CSICOur aim with this paper is to provide insight into the landscape dynamics of the Cantabrian region (northern Iberian Peninsula) from the Last Glacial Period to the present. We present a multiproxy approach performed in a sedimentary record from La Molina peat bog, located at 484 m a. s. l. in Puente Viesgo, Cantabria (Latitude: 43.26° N; Longitude: 3.97° W), that covers the last c. 17,550 years. Analyses were performed on the organic matter, pollen and sedimentary charcoals, which have been used to characterise the fire regime at a local level. The results revealed a steppe-like formation from the basis of the sequence to the Bølling-Allerød chronozone, when the spread of woody species is detected. The dry and cold conditions of the Younger Dryas caused the decrease of mesophilous taxa until the onset of the Holocene. From that point onwards, a mixed deciduous formation composed of Betula and deciduous Quercus was established in the region. Besides, a series of biomass pulses was detected during the early Holocene, probably linked to intervals of increased rainfall. Fire episodes detected at the 9.3 and the 8.2 ka events created forest openings and probably favoured the establishment of Corylus, most likely also helped by a climate shift. There was a lack of fire activity until the Neolithic, when the fire signal increased probably linked to grazing and agricultural practices and triggered deeper changes in the Cantabrian plant landscape structure

Lizonia baldini sobre Polytrichum formosum

S'ha trobat al Montseny (UTM:DG 46 26) l'ascomicet briofil Lizonia baldini (Pir) Dobb (Ordre Dothideales) parasit sobre Polytrichum formosum Hedw. Es descriuen les característiques dels exemplars observats i s'indica la seva incidencia en la producció d'anteridisSe ha encontrado en el Montseny (UTM:DG 46 26 )el ascomicete briófilo Lizonia baldini (Pir) Dobb (Orden Dothideales) parásito sobre Polytrichum formosum Hedw. Se describen las características de los ejemplares observados. Se señala su incidencia en la producción de anteridiosThe ascomycete Lizonia baLdini (Pir) Dóbb (Order Dothideales) a parasite on Polytrichum formosum Hedw., has been found in the Montseny area (UTM:DG 46 26). Characteristics of the examples that were observed are described below. Its incidence in the production of antheridia is indicated

DNA metabarcoding reveals modern and past eukaryotic communities in a high-mountain peat bog system

Peat bogs located in high mountains are suitable places to study local environmental responses to climate variability. These ecosystems host a large number of eukaryotes with diverse taxonomic and functional diversity. We carried out a metabarcoding study using universal 18S and COI markers to explore the composition of past and present eukaryotic communities of a Pyrenean peat bog ecosystem. We assessed the molecular biodiversity of four different moss micro-habitats along a flood gradient in the lentic Bassa Nera system (Central Pyrenees). Five samples collected from different sediment depths at the same study site were also analysed, to test the suitability of these universal markers for studying paleoecological communities recovered from ancient DNA and to compare the detected DNA sequences to those obtained from the modern community. We also compared the information provided by the sedimentary DNA to the reconstruction from environmental proxies such as pollen and macro-remains from the same record. We successfully amplified ancient DNA with both universal markers from all sediment samples, including the deepest one (~ 10,000 years old). Most of the metabarcoding reads obtained from sediment samples, however, were assigned to living edaphic organisms and only a small fraction of those reads was considered to be derived from paleoecological communities. Inferences from ancient sedimentary DNA were complementary to the reconstruction based on pollen and macro-remains, and the combined records reveal more detailed information. This molecular study yielded promising findings regarding the diversity of modern eukaryotic peat bog communities. Nevertheless, even though information about past communities could be retrieved from sediment samples, preferential amplification of DNA from living communities is a caveat for the use of universal metabarcoding markers in paleoecology

La alta montaña durante la Prehistoria: 10 años de investigación en el Pirineo catalán occidental

Archaeological survey and test excavations were conducted at high altitude in the western Catalan Pyrenees since 2001 to 2010. Together with palaeoecological studies of lake cores and peat bogs, these studies (including a series of 27 radiocarbon dates) permit one to discuss human occupations of the high mountains from Mesolithic times to the early Bronze Age. We evaluate the role played by mountain areas in the development of prehistoric communities with particular attention to the process of postglacial colonization, the introduction and development of farming and other agricultural practices, as well as complementary economic activities like mining, charcoal- burning and lumber production, with particular attention to the relation of mountain communities to those of other regions