El género Ulota Mohr en la Península Ibérica y una nueva visión del Complejo de U crispa (Hedw.) Brid. (Orthotrichaceae, Musci)

La presente tesis doctoral tiene como objetivo general tratar de avanzar de una manera significativa en la taxonomía del género Ulota, sentando las bases para el estudio moderno de su diversidad. Para conseguirlo, primero se ha tratado de obtener una perspectiva general del género,centrada en el hemisferio norte aunque no restringida al mismo, mediante el estudio de más de 1.500 especímenes procedentes de numerosos herbarios (ALA, BCB, BM, BP, DUKE, FCO, FH, G, H, HIRO, LISU, MA, MAUAM, MHA, MO, MUB, NICH, NYBG, S, TU VIT, y herbarios personales de P. Boudier y D. Callaghan), así como de recolecciones realizadas ex profeso en diferentes partes del mundo por el equipo de trabajo (Turquía, Península Ibérica, costa pacífica de Norteamérica y Japón). En una segunda etapa se ha abordado la revisión de los materiales ibéricos en el marco del proyecto Flora Briofítica Ibérica, trabajo en el que se ha descrito e ilustrado minuciosamente todas las especies reconocidas, además de aportar diversos datos sobre su distribución y preferencias ecológicas. La labor ha tenido como preocupación primordial el facilitar la distinción de las especies, lo que se ha tratado de conseguir a través de la elaboración de una clave sencilla pero precisa, que incorpora nuevos caracteres taxonómicos junto a otros ya probados, y mediante abundantes comentarios sobre la separación de taxones similares. Finalmente, se ha afrontado el estudio taxonómico en profundidad del complejo de Ulota crispa a escala global. Este grupo ha sido considerado una pieza clave para la comprensión del género en el hemisferio norte, por haber sido U. crispa el patrón comparativo al que se han referido numerosas descripciones de otras especies. Para ello se ha realizado un análisis morfológico detallado, basado en cerca de un millar de muestras procedentes de tres continentes. Como resultado del mismo se ha obtenido una batería de caracteres cualitativos y cuantitativos que permiten diferenciar tres morfotipos en el seno del complejo. A través del estudio de los materiales originales de Orthotrichum crispum (≡Ulota crispa), U. crispula y U. intermedia, estos dos últimos taxones tratados en la sinonimia de U. crispa en las últimas décadas, se ha logrado la correcta identificación de los tres morfotipos diferenciados durante el análisis morfológico. El hallazgo ha permitido la lectotipificación de estos tres nombres. Paralelamente, el análisis morfológico ha sido combinado con un estudio molecular para tratar de comprobar si las conclusiones del primero tienen un soporte genético. Para ello se han empleado secuencias de cuatro marcadores, uno nuclear (ITS2) y tres plastidiales (trnG, trnL-trnF,atpB-rbcL), obtenidas de 25 especímenes adscritos a los distintos morfotipos o especies diferenciadas en el complejo, procedentes de diferentes partes de Norteamérica y Eurasia. Como resultado de este estudio de taxonomía integrativa, se ha podido comprobar la segregación específica que la morfología sugería y se ha procedido a delimitar con precisión cada una de las tres especies que integran el complejo. Asimismo, el análisis de la procedencia geográfica de los materiales estudiados ha permitido establecer patrones de distribución geográfica de los componentes del grupo. Gracias a este conjunto de estudios, realizados a diferentes escalas taxonómicas y geográficas, se ha podido presentar una visión contrastada sobre la utilidad de muchos caracteres, tanto clásicos como otros propuestos aquí por primera vez. Igualmente, se ha podido identificar una serie de conflictos taxonómicos relacionados con especies del hemisferio norte, que deberían ser abordados en un futuro mediante técnicas similares a las empleadas durante la tesis doctoral

External forcings, oceanographic processes and particle flux dynamics in Cap de Creus submarine canyon, NW Mediterranean Sea

Particle fluxes (including major components and grain size), and oceanographic parameters (near-bottom water temperature, current speed and suspended sediment concentration) were measured along the Cap de Creus submarine canyon in the Gulf of Lions (GoL; NW Mediterranean Sea) during two consecutive winter-spring periods (2009 2010 and 2010 2011). The comparison of data obtained with the measurements of meteorological and hydrological parameters (wind speed, turbulent heat flux, river discharge) have shown the important role of atmospheric forcings in transporting particulate matter through the submarine canyon and towards the deep sea. Indeed, atmospheric forcing during 2009 2010 and 2010 2011 winter months showed differences in both intensity and persistence that led to distinct oceanographic responses. Persistent dry northern winds caused strong heat losses (14.2 × 103 W m−2) in winter 2009 2010 that triggered a pronounced sea surface cooling compared to winter 2010 2011 (1.6 × 103 W m−2 lower). As a consequence, a large volume of dense shelf water formed in winter 2009 2010, which cascaded at high speed (up to ∼1 m s−1) down Cap de Creus Canyon as measured by a current-meter in the head of the canyon. The lower heat losses recorded in winter 2010 2011, together with an increased river discharge, resulted in lowered density waters over the shelf, thus preventing the formation and downslope transport of dense shelf water. High total mass fluxes (up to 84.9 g m−2 d−1) recorded in winter-spring 2009 2010 indicate that dense shelf water cascading resuspended and transported sediments at least down to the middle canyon. Sediment fluxes were lower (28.9 g m−2 d−1) under the quieter conditions of winter 2010 2011. The dominance of the lithogenic fraction in mass fluxes during the two winter-spring periods points to a resuspension origin for most of the particles transported down canyon. The variability in organic matter and opal contents relates to seasonally controlled inputs associated with the plankton spring bloom during March and April of both years.This research has been supported by the ECfunded HERMIONE (FP7-ENV-2008-1-226354

Particle fluxes in submarine canyons along a sediment-starved continental margin and in the adjacent open slope and basin in the SW Mediterranean Sea

Investigating the transfer of particulate matter from the continental shelf to the deep basin is critical to understand the functioning of deep sea ecosystems. In this paper we present novel results on the temporal variability of particle fluxes to the deep in three physiographic domains of a 240 km long margin segment and nearby basin off Murcia and Almeria provinces in the SW Mediterranean Sea, which are submarine canyons forming a rather diverse set (namely Escombreras, Garrucha-Almanzora and Almeria), the adjacent open slope and the deep basin. This margin is located off one of the driest regions in Europe and, therefore, its study may help understanding how mainland aridity translates into the export of particles to deep margin environments. Five mooring lines equipped with currentmeters, turbidity-meters and sediment traps were deployed for one entire annual cycle, from March 2015 to March 2016. We combine oceanographic, hydrological and meteorological data with grain size and bulk elemental data (organic carbon, opal, CaCO3, lithogenic) from the collected sinking particles to understand what drives particle transfers in such an under-studied setting, and to quantify the resulting fluxes and assess their spatio-temporal variability. Weighted total mass fluxes in canyons range from 1.64 g m−2 d−1 in Almeria Canyon to 7.33 g m−2 d−1 in Garrucha-Almanzora Canyon system, which are rather low values compared to other submarine canyons in the Western Mediterranean Sea. This results from the absence of extreme wind-storm events during the investigated time period combined with the reduced sediment input to the inner shelf by river systems in the study area. Our results also show that wind-storms are the main trigger for off-shelf particle transport to the deep margin, both within submarine canyons and over the open slope. The most significant transfer period is associated to a set of north-eastern storms in early spring 2015, when the off-shelf transport likely was promoted by storm-induced downwelling. However, the prevailing oceanographic conditions restricts the advection of water down the canyon heads to a few hundred meters, thus promoting a bottom-detached transport of particles seaward. Overall physiography, canyon head incision into the continental shelf and the distance of the canyon head to the shoreline (e.g. very short in Garrucha Canyon) play a key role in particle trapping capability and, therefore, in easing downslope particle transport. Further, bottom trawling activities around the Garrucha-Almanzora Canyon system, feed a nepheloid layer at depths in excess of 400 m, subsequently enhancing particle fluxes throughout the study period. In contrast, maximum particle fluxes in the deep basin respond to seasonal phytoplankton blooms. Our study shows that particle export from the shallow inner margin to the deep outer margin in sediment-starved settings, even if limited, does occur as dominated by atmosphere and ocean driven short-lived events. However, that export does not reach too far as at several tens of kilometres from the shelf edge advective fluxes are replaced by vertical ones impelled by phytoplankton dynamics

Deep-water formation variability in the north-western Mediterranean Sea during the last 2500yr: A proxy validation with present-day data

Here we investigate the sensitivity of deep-water formation in the north-western Mediterranean Sea to climate variability during the last 2500 yr. With this purpose, the grain-size parameter UP10 (fraction > 10 μm) is used as a proxy for intensity of deep-water circulation. Such a proxy is first validated through the analysis of oceanographic data collected from October 2012 to October 2014 by means of two deep-water mooring lines equipped with sediment traps and currentmeters in the Gulf of Lion and north of Minorca Island. Enhancements of deep current speed resulted from dense shelf water cascading and open-sea deep convection in February 2013 leading to dense-water formation. The grain-size distribution of settling particles from sediment traps collected during 2012-2013 shows a distinctive particle mode and high UP10 values correlated to deep-water formation. These data are consistent with grain-size values in sediment cores from the north of Minorca, thus supporting the validity of the UP10 parameter to reconstruct changes of intensity in deep-water formation and associated near-bottom currents. The deep-water sediment record of the north of Minorca for the last 2.5 kyr shows that the strongest deep-water formation events occurred during relatively warm intervals, such as the Roman Period (123 BCE-470 CE2), the end of the Medieval Climate Anomaly (900-1275 CE) and the first part of the Little Ice Age (1275-1850 CE). By contrast, our data indicate a progressive reduction in the overturning conditions during the Early Middle Ages (470-900 CE) resulting in weaker deep-water formation events during most of the Medieval Climate Anomaly. Intense deep-water formation events appear to be mostly associated with periods of enhanced Evaporation-Precipitation balance rather than to buoyancy loss due to winter cooling only. Our results suggest that warm sea surface temperature during spring months could have played an important role by increasing the Evaporation-Precipitation balance and favouring buoyany loss by increased of salinity. The comparison our data with other oceanographic and climatic records indicates a change in the proxy relation before and after the Early Middle Ages. Western Mediterranean Deep Water and Levantine Intermediate Water behave in opposite way after the Early Middle Ages, thus indicating that the previously proposed Mediterranean see-saw pattern in the Evaporation-Precipitation balance also influenced convection patterns in the basins during the last 1500 yr. These changes are discussed in the frame of different configurations of the North Atlantic Oscillation and East Atlantic/ West Russian modes of atmospheric variation

Tackling a long-standing problem: Typification of <i>Orthotrichum crispum</i>, <i>Ulota crispula</i> and <i>Ulota intermedia</i> (Bryopsida: Orthotrichaceae)

Previous taxonomic studies on the Holarctic species of Ulota, including both morphological and molecular approaches,distinguished Ulota crispa, U. crispula and U. intermedia as separate taxa worthy of recognition at the specific level, instead of belonging to a single, highly variable species (U. crispa). Available original material for these three names has been studied and in several cases these are heterogeneous, containing two or even three of these closely related species. We discuss the nomenclatural history of each species and the extant original specimens from which lectotypes for Orthotrichum crispum,Ulota crispula and U. intermedia are designated

Particle fluxes in submarine canyons along a sediment-starved continental margin and in the adjacent open slope and basin in the SW Mediterranean Sea

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tarrés, M., Cerdà-Domènech, M., Pedrosa-Pàmies, R., Rumín-Caparrós, A., Calafat, A., Canals, M., & Sanchez-Vidal, A. Particle fluxes in submarine canyons along a sediment-starved continental margin and in the adjacent open slope and basin in the SW Mediterranean Sea. Progress in Oceanography, 203, (2022): 102783, https://doi.org/10.1016/j.pocean.2022.102783.Investigating the transfer of particulate matter from the continental shelf to the deep basin is critical to understand the functioning of deep sea ecosystems. In this paper we present novel results on the temporal variability of particle fluxes to the deep in three physiographic domains of a 240 km long margin segment and nearby basin off Murcia and Almeria provinces in the SW Mediterranean Sea, which are submarine canyons forming a rather diverse set (namely Escombreras, Garrucha-Almanzora and Almeria), the adjacent open slope and the deep basin. This margin is located off one of the driest regions in Europe and, therefore, its study may help understanding how mainland aridity translates into the export of particles to deep margin environments. Five mooring lines equipped with currentmeters, turbidity-meters and sediment traps were deployed for one entire annual cycle, from March 2015 to March 2016. We combine oceanographic, hydrological and meteorological data with grain size and bulk elemental data (organic carbon, opal, CaCO3, lithogenic) from the collected sinking particles to understand what drives particle transfers in such an under-studied setting, and to quantify the resulting fluxes and assess their spatio-temporal variability. Weighted total mass fluxes in canyons range from 1.64 g m−2 d−1 in Almeria Canyon to 7.33 g m−2 d−1 in Garrucha-Almanzora Canyon system, which are rather low values compared to other submarine canyons in the Western Mediterranean Sea. This results from the absence of extreme wind-storm events during the investigated time period combined with the reduced sediment input to the inner shelf by river systems in the study area. Our results also show that wind-storms are the main trigger for off-shelf particle transport to the deep margin, both within submarine canyons and over the open slope. The most significant transfer period is associated to a set of north-eastern storms in early spring 2015, when the off-shelf transport likely was promoted by storm-induced downwelling. However, the prevailing oceanographic conditions restricts the advection of water down the canyon heads to a few hundred meters, thus promoting a bottom-detached transport of particles seaward. Overall physiography, canyon head incision into the continental shelf and the distance of the canyon head to the shoreline (e.g. very short in Garrucha Canyon) play a key role in particle trapping capability and, therefore, in easing downslope particle transport. Further, bottom trawling activities around the Garrucha-Almanzora Canyon system, feed a nepheloid layer at depths in excess of 400 m, subsequently enhancing particle fluxes throughout the study period. In contrast, maximum particle fluxes in the deep basin respond to seasonal phytoplankton blooms. Our study shows that particle export from the shallow inner margin to the deep outer margin in sediment-starved settings, even if limited, does occur as dominated by atmosphere and ocean driven short-lived events. However, that export does not reach too far as at several tens of kilometres from the shelf edge advective fluxes are replaced by vertical ones impelled by phytoplankton dynamics.This work was supported by research projects NUREIEV (ref. CTM2013-44598-R) and NUREIEVA (ref. CTM2016-75953-C2-1-R). GRC Geociències Marines is funded by the Catalan Government within its excellence research groups program (ref. 2017 SGR 315). M.Tarrés was supported by a FPI grant from Ministerio de Ciencia, Innovación y Universidades of the Spanish Government

Spores potentially dispersed to longer distances are more tolerant to ultraviolet radiation: a case study in the moss genus Orthotrichum

Premise of the Study: Ultraviolet (UV) radiation influences the viability of algal spores and seed-plant pollen depending on the species, the dose, and the wavelength. In bryophytes, one of the dominant groups of plants in many habitats, UV radiation could determine their spore dispersal strategy, and such data are critical for reconstructing the ancestral state in plants and for determining the distribution range and persistence of bryophyte species. Methods: Spores of four bryophyte species of the moss genus Orthotrichum that were either hygrochastic or xerochastic (spores dispersed under wet or dry conditions, respectively) were exposed to realistic doses of UV radiation under laboratory conditions. Spore viability was evaluated through germination experiments and, for the first time in bryophytes, ultrastructural observations. Given that the UV-B doses used were relatively higher than the UV-A doses, the UV effect was probably due more to UV-B than UV-A wavelengths. Key Results: All four species reduced their spore germination capacity in a UV dose-dependent manner, concomitantly increasing spore ultrastructural damage (cytoplasmic and plastid alterations). Most spores eventually died when exposed to the highest UV dose. Interestingly, spores of hygrochastic species were much more UV-sensitive than those of xerochastic species. Conclusions: UV tolerance determines moss spore viability, as indicated by germination capacity and ultrastructural damage, and differs between spores of species with different dispersal strategies. Specifically, the higher UV tolerance of xerochastic spores may enable them to be dispersed to longer distances than hygrochastic spores, thus extending more efficiently the distribution range of the corresponding speciesWe thank two anonymous reviewers for their valuable comments to improve the manuscript. ENO, JMA, LM, and MADCA thank the Ministerio de Economía y Competitividad of Spain (MINECO) and FEDER (Project CGL2014- 54127- P) for financial support. MADCA benefited from a grant of the Universidad de La Rioja (Plan Propio 2014

External forcings, oceanographic processes and particle flux dynamics in Cap de Creus submarine canyon, NW Mediterranean Sea

Particle fluxes (including major components and grain size), and oceanographic parameters (near-bottom water temperature, current speed and suspended sediment concentration) were measured along the Cap de Creus submarine canyon in the Gulf of Lions (GoL; NW Mediterranean Sea) during two consecutive winter-spring periods (2009 2010 and 2010 2011). The comparison of data obtained with the measurements of meteorological and hydrological parameters (wind speed, turbulent heat flux, river discharge) have shown the important role of atmospheric forcings in transporting particulate matter through the submarine canyon and towards the deep sea. Indeed, atmospheric forcing during 2009 2010 and 2010 2011 winter months showed differences in both intensity and persistence that led to distinct oceanographic responses. Persistent dry northern winds caused strong heat losses (14.2 × 103 W m−2) in winter 2009 2010 that triggered a pronounced sea surface cooling compared to winter 2010 2011 (1.6 × 103 W m−2 lower). As a consequence, a large volume of dense shelf water formed in winter 2009 2010, which cascaded at high speed (up to ∼1 m s−1) down Cap de Creus Canyon as measured by a current-meter in the head of the canyon. The lower heat losses recorded in winter 2010 2011, together with an increased river discharge, resulted in lowered density waters over the shelf, thus preventing the formation and downslope transport of dense shelf water. High total mass fluxes (up to 84.9 g m−2 d−1) recorded in winter-spring 2009 2010 indicate that dense shelf water cascading resuspended and transported sediments at least down to the middle canyon. Sediment fluxes were lower (28.9 g m−2 d−1) under the quieter conditions of winter 2010 2011. The dominance of the lithogenic fraction in mass fluxes during the two winter-spring periods points to a resuspension origin for most of the particles transported down canyon. The variability in organic matter and opal contents relates to seasonally controlled inputs associated with the plankton spring bloom during March and April of both years.This research has been supported by the ECfunded HERMIONE (FP7-ENV-2008-1-226354