L'estela ibèrica de Tona (Osona)

Revisió d'una estela iberica, descoberta l'any 1915, motivada per la troballa d'un manuscrit inedit d' A. Romaní (1926) i per la contrastació d'aquest amb les indicacions publicades per J. Oudiol (1916) i J. Danés (1932). La recuperació i relectura d'aquestes vclles fonts permeten precisar millor algunes qüestions, com ellloc on fou localitzada o les vicissituds sofertes per la llosa, matisos no contemplats en l'estudi de J. Maluquer de Motes (1982). Es prossegueix amb una analisi detallada deIs fragments conservats al Museu Episcopal de Vic i, per primera vegada, s'inclou un dibuix directe acompanyat d'una reconstrucció hipotetica del seu aspecte en el moment d'aparició. També es dóna notícia de la localització a Tona d'un segon relleu. Tanquen l'estudi diverses consideracions respecte a la tecnica emprada, la morfologia, el programa iconic, la filiació i la possible cronologia. L'estela mostra lligams directes amb monuments afins ubicats al nord de l'Ebre i, en sentit ampli, amb el grup del Baix Aragó, fet que obliga a reconsiderar la problematica deIs suposats «ausetans de l'Ebre».

Seasonal patterns op biomass variation of Ruppia cirrhosa (Petagna) Grande and Potamageton pectinatus L. in a coastal logoon

Coastal lagoons where salinity varies within a wide range during the year are colonized by euryhaline macrophytes which can develop extensive beds. Seasonal changes in biomass of Ruppia cirrhosa and Potamogeton pectinatus were studied in Tancada Lagoon (Ebro Delta, NE Spain) in order to reveal the environmental factors controlling their population development. Ruppia cirrhosa occupy a larger area of the lagoon than Potarnogeton pectinatus. Their maximum above ground biomasses are also different (495 g m-2 and 351 g m-2 ash free dry weight, respectively). Below ground biomass of Ruppia cirrhosa is between 9 and 53 % of the above ground biomass, while it is 3-40 % for Potamogeton pectinatus. Chlorophyll a contents show fluctuations similar to biomass. Low salinity and high turbidity caused by freshwater inflows favour Potamogeton expansion, while Ruppia development is favoured by high salinity and transparent water.

Decomposition of Ruppia cirrhosa (Petagna) Grande in the sediment of a coastal lagoon

The decomposition process of Ruppia cirrhosa was studied in a Mediterranean coastal lagoon in the Delta of the River Ebro (NE Spain). Leaves and shoots of Ruppia were enclosed in 1 mm-mesh and 100 pm-mesh litter bags to ascertain the effect of detritivores, macroinvertebrates, and bacteria and fungi, respectively. Changes in biomass and carbon, and, nitrogen and phosphorus concentrations in the detritus were studied at the sediment-water interface and in the sediment. Significant differences in biomass decay were observed between the two bag types. Significant differences in decomposition were observed between the two experimental conditions studied using 100 pm-mesh bags. These differences were not significant when using the 1 mm-mesh bags. The carbon content in the detritus remained constant during the decomposition process. The percentage of nitrogen increased progressively from an initial 2.4 % to 3 %. The percentage of phosphorus decreased rapidly during the first two days of decomposition from an initial 0.26 % to 0.17 %. This loss is greater in the sediment than in the water column or at the sediment-water interface. From these results we deduce that the activity of microorganisms seems to be more important in the sediment than in the water-sediment interface, and that grazing by macroinvertebrates has less importance in the sediment than in the water column.

Rockfall monitoring by Terrestrial Laser Scanning ¿ case study of the basaltic rock face at Castellfollit de la Roca (Catalonia, Spain)

This case study deals with a rock face monitoring in urban areas using a Terrestrial Laser Scanner. The pilot study area is an almost vertical, fifty meter high cliff, on top of which the village of Castellfollit de la Roca is located. Rockfall activity is currently causing a retreat of the rock face, which may endanger the houses located at its edge. TLS datasets consist of high density 3-D point clouds acquired from five stations, nine times in a time span of 22 months (from March 2006 to January 2008). The change detection, i.e. rockfalls, was performed through a sequential comparison of datasets. Two types of mass movement were detected in the monitoring period: (a) detachment of single basaltic columns, with magnitudes below 1.5 m3 and (b) detachment of groups of columns, with magnitudes of 1.5 to 150 m3. Furthermore, the historical record revealed (c) the occurrence of slab failures with magnitudes higher than 150 m3. Displacements of a likely slab failure were measured, suggesting an apparent stationary stage. Even failures are clearly episodic, our results, together with the study of the historical record, enabled us to estimate a mean detachment of material from 46 to 91.5 m3 year¿1. The application of TLS considerably improved our understanding of rockfall phenomena in the study area.

Rockfall induced seismic signals: case study in Montserrat, Catalonia

After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. Seismic measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, seismic techniques could provide important information on rockfall size and location of impacts. On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the seismic data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain) carried out in order to purge a slope. Two 3 component seismic stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. Seismic signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10¿4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the release zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the seismic records and seismic energy estimation were performed. The results are as follows: 1 ¿ A rockfall event generates seismic signals with specific characteristics in the time domain; 2 ¿ the seismic signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact). This feature could be used for detection purposes; 3 ¿ particle motion plot analysis shows that the procedure to locate the rock impact using two stations is feasible; 4 ¿ The feasibility and validity of seismic methods for the detection of rockfall events, their localization and size determination are comfirmed.

Algunes plantes dels Ports de Beseit (Catalunya meridional)

Notas florísticas sobre plantas vasculares de los Ports de Beseit. Algunas son nuevas citas para esta zona: Ephedra nebrodensis, Equisetum palustre, Iberis saxatilis subsp. saxatihs; otras raras: Neotinea maculata, Ridolfia segetum, Ranunculus parviflorus. Arrbenatberum album es indicado por primera vez en Cataluña.

Correlation between species composition and soil properties in the pastures of Plana de Vic (Catalonia, Spain)

The correlation between the species composition of pasture communities and soil properties in Plana de Vic has been studied using two multivariate methods, Correspondence Analysis (CA) for the vegetation data and Principal Component Analysis (PCA) for the soil data. To analyse the pastures, we took 144 vegetation relevés (comprising 201 species) that have been classified into 10 phytocoenological communities elsewhere. Most of these communities are almost entirely built up by perennials, ranging from xerophilous, clearly Mediterranean, to mesophilous, related to medium-European pastures, but a few occurring in shallow soils are dominated by therophytes. As for the soil properties, we analysed texture, pH, depth, bulk density, organic matter, C/N ratio and the carbonates content of 25 samples, correspondingto representative relevés of the communities studied.

Addicions a la flora vascular del Parc Natural del Cadí-Moixeró i de les serres veïnes (Prepirineus Orientals Ibèrics)

Additions to the vascular flora of the Cadí-Moixeró Natural Park and neighbouring Pre-Pyrenean areas (eastern Iberian Pyrenees) We present about fifty contributions to the catalogue of the vascular flora of the mentioned area, published in 2003. Among the taxa reported, 21 correspond to novelties found in our own field observations or in the literature. We highlight the first records for the Eastern Iberian Pre-Pyrenees of Meconopsis cambrica (L.) Vig. and Omalotheca hoppeana (Koch) Schulz Bip. and F.W. Schulz. Other data refer to rare taxa already included in the catalogue, such as Gagea lutea (L.) Ker Gawl., G. reverchonii Degen, Lappula deflexa (Wahlenb.) Garcke and Minuartia villarii (Balb.) Wilczek and Chenevard.

Syntaxonomic conspectus of the vegetation of Catalonia and Andorra. I: Hygrophilous herbaceous communities.

The first part of a general survey of the vegetation of Catalonia andAndorra, this paper reports all the phytocoenological associations and subassociations recorded in this area. For each community, we provide the correct name and usual synonyms, its typification (where appropriate), all the references including relevés, and the most outstanding features of its structure, species composition, ecology, distribution and diversity. Moreover, associations and subassociations are ordered appropriately in a syntaxonomic scheme. Syntaxonomic ranks are considered in a fairly broad, conservative sense. This classification established 101 associations, which correspond to the classes Lemnetea, Zosteretea, Potametea, Littorelletea, Montio-Cardaminetea, Phragmiti-Magnocaricetea, Scheuchzerio-Caricetea, Isoeto-Nanojuncetea and Molinio-Arrhenatheretea.

Plantas vasculares del piso alpino de los Pirineos Catalanes raras o amenazadas

Como contribución al conocimiento de la flora supraforestal pirenaica y a la política de protección medioambiental, presentamos una relación de los táxones cormofíticos raros o amenazados, existentes en el piso alpino de los Pirineos dentro de los territorios que dependen administrativamente de la Generalitat de Cataluña, Andorra y el departamento de los Pyrénées- Orientales. Dichos táxones se agrupan en seis subapartados, según su área de distribución y su grado de rareza en el territorio considerado. Las plantas especialmente raras o vulnerables se señalan mediante un asterisco situado a continuación del nombre científico. Para la mayoría de los táxones aportamos datos más concretos referentes a distribución y frecuencia.

Una nova subespàcie de Pedicularis pyrenaica J. Gay (Scrophulariaceae) als Pirineus Centrals

A new subspecies of Pedicularis pyrenaica J. Gay (Scrophulariaceae) in Central Pyrenees. We describe a new subspecies of Pedicularis pyrenaica (P. pyrenaica subsp. praetermissa) from the Central Pyrenees, which differs from the typical in the shape of the upper lip of the corolla (fusiform, attenuated in a conical beak), as for the larger size of the corolla and the whole plant. We add several comments on the morphological characterization and the habitat of the plant in relation to close taxa

Diagnòstic en profunditat sobre la integració dels i les joves de 14 a 18 anys migrats a Catalunya

[cat] La finalitat d’aquest projecte és aprofundir en el procés d’integració socioeducativa de la joventut migrada a Catalunya, específicament, dels i les joves entre 14 i 18 anys. Entre els resultats destaquem que els joves tenen un concepte força tancat i excloent del concepte de ciutadania com a estatus, i un baix grau de coneixement de la diversitat cultural, especialment els joves autòctons; tot i que tenen una actitud de reconeixement i acceptació, favorable a la convivència intercultural, tant al centre educatiu com al seu barri. No obstant, tenen una visió de la diversitat cultural i del fet migratori en clau de coexistència, sense el reconeixement que suposaria un pas més per a la convivència. La immigració és vista com un col·lectiu vulnerable, amb un baix nivell econòmic i cultural i que també és percebut com un problema i, fins i tot, com a causant de les dificultats que actualment pateix i travessa el conjunt de la societat. Els joves tendeixen a relacionar-se amb el seu grup cultural, i responen de forma passiva en la comprensió i actuació davant dels problemes i assumptes públics. Entre els elements que valoren per sentir-se ciutadà té una especial importància la llengua. Els joves que fa més de 10 anys que viuen a Catalunya són els que tendeixen a tenir un sentiment de pertinença cívica amb el lloc de residència. De fet, com més temps porten els joves estrangers vivint al lloc d’acollida, perden importància elements d’identificació cultural del país d’origen, però la religió, les celebracions populars, l’art i la tendència a formar parella són elements identitaris del lloc d’origen, més estables. Es demana una intervenció urgent en diversos nivells i destinades a diferents agents. Destaquem: -La importància d’una acollida afectiva i efectiva, -Potenciar espais de trobada, -Treballar els prejudicis, -Transversalitzar l’educació intercultural, - Potenciació de l’aprenentatge de la llengua catalana, -Formació del professorat en competències interculturals.