Epiphyton in Agricultural Streams: Structural Control and Comparison to Epilithon

Stream biofilms play an important role in the structure, functioning, and integrity of agricultural streams. In many lowland streams, macrophyte vegetation is abundant and functions as an important substrate for biofilm (epiphyton) in addition to the gravel and stone substrate for epilithon on the stream bed. We expect that reach-scale habitat conditions in streams (e.g., nutrient availability, hydraulic conditions) affect the epiphyton and epilithon biomass and composition, and that this effect will be substrate-specific (macrophytes and stones). The objectives of our study were (i) to describe concurrent changes in epiphyton and epilithon biomass and composition over a year in agricultural streams, and (ii) to determine the substrate specific reach-scale habitat drivers for the epiphyton and epilithon structure. We monitored epiphyton and epilithon biofilm biomass and composition at three-week intervals and reach-scale environmental conditions daily during a year for two agricultural steams. The results showed that epiphyton and epilithon communities differed in biomass, having high substrate specific biomass in epilithon compared to epiphyton. Epiphyton was mainly composed of diatom and green algae, while cyanobacteria were more important in epilithon, and the diatom species composition varied between the two biofilm types. Epiphyton structural properties were less influenced by reach-scale hydrology and nutrient availability compared to epilithon. The overall explanatory power of the measured environmental variables was low, probably due to micro-scale habitat effects and interactive processes within stream biofilms. Knowledge of biofilm control in agricultural streams is important in order to improve management strategies, and future studies should improve the understanding of micro-scale habitat conditions, interactive relationships within biofilms and between the biofilm and the substrates

Deployment of ENEX enclosures in high‐mountain lake Redon (Spain)

The ENEX experiment in Lake Redon (Pyrenees) investigated the relationship between the changes in plankton stoichiometry, productivity, and community structure occurring during nutrient fluctuations in P‐limited conditions. Columnar enclosures were used for treatments varying P availability, N:P imbalance, and N source. C:N:P seston ratios were stable in P‐limited conditions, with loose coupling with productivity, nutrient supply ratios, and species dominance. The stoichiometric ratios shifted to Redfield proportions in P‐repleted conditions. The results suggest a complex regulation of P scarcity in planktonic communities that goes beyond immediate acclimation growth responses and might include alternative physiological and biogeochemical states

Episodic nutrient enrichments stabilise protists coexistence in planktonic oligotrophic conditions

1. Seasonal compositional changes in plankton communities are usually considered as species replacements. Provided the enormous number of individuals integrating the communities and our limited capacity for counting and determining a substantial proportion of them, it may happen that we would only be observing alternative population peaks of a large number of coexisting species. The contemporary coexistence theory addresses coexistence in communities of competing species considering simultaneously relative fitness inequalities and stabilising niche differences as components of average long-term growth rates. Here, we experimentally show that response patterns predicted by the theory occur when varying nutrient pulses fertilise the planktonic community. 2. We used gently self-filling 100 L enclosures to minimise disturbance of the initial community and different pulse P and N additions to manipulate the apparently species-poor epilimnetic community of an ultraoligotrophic P-limited lake. We measured and compared protist species growth response to a gradient of P enrichment and another of N stoichiometric imbalance. The P and N levels selected were within the oligotrophic seasonal and interannual variation of the lake, plus some extreme treatments providing mesotrophic conditions of remote regions affected by N atmospheric contamination. All treatments were replicated using ammonium or nitrate alternatively as N source. 3. Most protist species ¿ recorded across seasons in previous studies in this lake ¿ were recovered, indicating a persistent assemblage of species that is seasonally-hidden to observation. Recovery included some rare species only observed in the slush layers of the seasonal snow and ice cover. Coexistence stabilising mechanisms were indicated by treatment response features such as frequency-dependent growth, inverse relationship between fitness inequality and niche differentiation proxies, high-rank taxonomic levels clustering across the limiting nutrient gradient but segregation at the species level according to the type of nitrogen supply, and resting stage development depending on nutrient conditions. Response similarities between autotrophic and heterotrophic organisms indicate a network of interactions that may reinforce coexistence. 4. Synthesis. The results indicate that many planktonic protist species in oligotrophic waters can show stable long-term non-equilibrium coexistence by alternately recovering from very low densities when episodic nutrient enrichments ¿ of varying P and N amounts and composition ¿ occur

Homeostasis and non-linear shift in the stoichiometry of P-limited planktonic communities

Planktonic communities are naturally subjected to episodic nutrient enrichments that may stress or redress the imbalances in limiting nutrients. Human‐enhanced atmospheric nitrogen deposition has caused profound N:P imbalance in many remote oligotrophic lakes in which phosphorus has largely become limiting. These lakes offer an opportunity to investigate the relationship between the changes in plankton stoichiometry, productivity, and community structure occurring during nutrient fluctuations in P‐limited conditions. We performed P ( PO3‐4) and N ( NH+4 or NO‐3) pulse additions to the summer epilimnetic community of an ultraoligotrophic lake using self‐filling ~100‐L enclosures and analyzed the response to varying P availability, N:P imbalance, and N source. Seston C:N:P proportions remained fairly unchanged to P additions that were within the range of values seasonally found in the lake. However, the seston N:P ratio abruptly shifted and approached Redfield's proportions at P additions typical of mesotrophic conditions that provided non‐limiting conditions. N surplus did not affect seston C:N:P proportions. The patterns of seston N:P stability and shift were similar for both N sources. In contrast, productivity was highly sensitive to low and medium P additions and decelerated at high P additions. Phytoplankton biomass dominated particulate organic matter. The autotrophic community differentiated almost linearly across the P gradient. Chrysophytes' dominance decreased, and diatoms and cryptophytes relative abundance increased. Nonetheless, the stoichiometry stability and non‐linear shift involved large biomass proportions of the same species, which indicates that the bulk stoichiometry was related to similar physiological behavior of phylogenetically diverse organisms according to the biogeochemical context. The C:N:P seston stability in P‐limited conditions with loose coupling with productivity, nutrient supply ratios, and species dominance and the sudden shift to Redfield proportions in P‐repleted conditions suggest a complex regulation of P scarcity in planktonic communities that goes beyond immediate acclimation growth responses and might include alternative physiological and biogeochemical states

Teaching difficulties. An analysis of the perceptions of Master's Degree Teacher Education students

Esta publicación es parte del proyecto «Diagnóstico de las competencias docentes del profesorado no universitario de la provincia de Valencia e identificación de las nuevas necesidades post-pandemia COVID-19. Propuestas de formación docente», de I+D+i CIGE/2021/014, financiado por la Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital (GE/2022).El profesorado es un elemento clave en la educación y su formación y concepción de la enseñanza determinan el éxito escolar. Este artículo trata de analizar las dificultades que autoperciben los estudiantes del Máster del Profesorado en su futuro desempeño profesional y establecer propuestas de mejora para su formación. Se analiza el patrón de puntuaciones de los estudiantes y las diferencias en función de la universidad de procedencia y del sexo. Se estudia la relación de predicción entre las Dificultades académicas y sociales en las Dificultades organizacionales, con las Dificultades materiales como mediadoras y la edad como factor influyente en esta relación. Es un estudio descriptivo y predictivo de las Dificultades organizacionales y materiales, donde se presta especial atención a las variables universidad de procedencia, edad y sexo. Participan 409 estudiantes, de distintas universidades valencianas. Se utiliza el Inventario de Problemas de Enseñanza. Entre los resultados destacan las dificultades para: relacionarse con las familias de los alumnos, organizar el tiempo de clase y gestionar el aula y la disciplina. Estos resultados coinciden con los de otras investigaciones. Además, las alumnas más mayores perciben mayores dificultades materiales; y aquellas que declaran mayores dificultades académicas también presentan mayores dificultades organizacionales. Se plantea la necesidad de implantar ciertas metodologías, potenciar la relación Universidad-escuela y mejorar el periodo de prácticas. Por lo que respecta al modelo causal analizado, se concluye que las Dificultades académicas y sociales influyen de forma directa sobre las organizacionales y que las materiales tienen un efecto mediador en esta relación.Teachers are one of the key elements in education and their training and conception of teaching influence school success. This article tries to analyze the difficulties self-perceived by the students of the master’s degree in teaching in their future professional performance and to establish proposals for improvement in their training. The pattern of students' scores and the differences according to the university of origin and gender are analyzed. The predictive relationship between academic and social difficulties in organizational difficulties is studied, with material difficulties as mediators and age as an influential factor in this relationship. It is a descriptive and predictive study of organizational and material difficulties, where special attention is paid to the variable’s university of origin, age, and gender. A total of 409 students from different Valencian universities participated. The Teaching Problems Inventory was used. Among the results, the following difficulties stand out: difficulties in relating with the students' families, organizing class time, and managing the classroom and discipline. These results coincide with those of other research. In addition, older students perceive greater material difficulties; and those who report greater academic difficulties also present greater organizational difficulties. There is a need to implement certain methodologies, to strengthen the university-school relationship and to improve the internship period. About the causal model analyzed, it is concluded that academic and social difficulties have a direct influence on organizational difficulties and that material difficulties have a mediating effect on this relationship.Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital (GE/2022) CIGE/2021/01

Dificultades de enseñanza. Un análisis de las percepciones de los estudiantes del Máster del Profesorado

Teachers are a key element in education and their training and conception of teaching determine school success. This article tries to analyze the difficulties self-perceived by the students of the Master's Degree in Teaching in their future professional performance and to establish proposals for improvement in their training. The pattern of students' scores and the differences according to the university of origin and gender are analyzed. The predictive relationship between academic and social difficulties in organizational difficulties is studied, with material difficulties as mediators and age as an influential factor in this relationship. It is a descriptive and predictive study of organizational and material difficulties, where special attention is paid to the variables university of origin, age and gender. A total of 409 students from different Valencian universities participated. The Teaching Problems Inventory was used. Among the results, the following difficulties stand out: difficulties in relating with the students' families, organizing class time and managing the classroom and discipline. These results coincide with those of other research. In addition, older students perceive greater material difficulties; and those who report greater academic difficulties also present greater organizational difficulties. There is a need to implement certain methodologies, to strengthen the university-school relationship and to improve the internship period. With regard to the causal model analyzed, it is concluded that academic and social difficulties have a direct influence on organizational difficulties and that material difficulties have a mediating effect on this relationship.El profesorado es un elemento clave en la educación y su formación y concepción de la enseñanza determinan el éxito escolar. Este artículo trata de analizar las dificultades que autoperciben los estudiantes del Máster del Profesorado en su futuro desempeño profesional y establecer propuestas de mejora para su formación. Se analiza el patrón de puntuaciones de los estudiantes y las diferencias en función de la universidad de procedencia y del sexo. Se estudia la relación de predicción entre las Dificultades académicas y sociales en las Dificultades organizacionales, con las Dificultades materiales como mediadoras y la edad como factor influyente en esta relación. Es un estudio descriptivo y predictivo de las Dificultades organizacionales y materiales, donde se presta especial atención a las variables universidad de procedencia, edad y sexo. Participan 409 estudiantes, de distintas universidades valencianas. Se utiliza el Inventario de Problemas de Enseñanza. Entre los resultados destacan las dificultades para: relacionarse con las familias de los alumnos, organizar el tiempo de clase y gestionar el aula y la disciplina. Estos resultados coinciden con los de otras investigaciones. Además, las alumnas más mayores perciben mayores dificultades materiales; y aquellas que declaran mayores dificultades académicas también presentan mayores dificultades organizacionales. Se plantea la necesidad de implantar ciertas metodologías, potenciar la relación Universidad-escuela y mejorar el periodo de prácticas. Por lo que respecta al modelo causal analizado, se concluye que las Dificultades académicas y sociales influyen de forma directa sobre las organizacionales y que las materiales tienen un efecto mediador en esta relación

Self-filling enclosures to experimentally assess plankton response to pulse nutrient enrichments

Experimental nutrient additions are a fundamental approach to investigating plankton ecology. Possibilities range from whole-lake fertilization to flask assays encompassing a trade-off between closeness to the "real world" and feasibility and replication. Here we describe an enclosure type that minimizes the manipulation of planktonic communities during the enclosure filling. The enclosure (typically ~100 L volume) consists of a narrow translucent cylinder that can comprise the entire photic zone (or a large part of it in clear deep lakes, e.g. 20-m long) and holds a sediment trap at the bottom for recovering the sinking material. The enclosures are inexpensive and straightforward to build. Thus, many can be used in an experiment, favoring the diversity of treatments and the number of replicates. They also are lightweight with easy transport and use in lakes that cannot be reached by road. The enclosures are fundamentally aimed at investigating the short-term response of the planktonic community, integrated across the photic zone, to pulse perturbations using before and after comparisons and multiple replication and treatments. The pros and cons of the enclosure design are evaluated based on experience gained in Lake Redon, a high mountain ultraoligotrophic deep lake in the Pyrenees

Controles locales y regionales del metabolismo en ríos de cabecera: aportaciones del primer proyecto colaborativo de la AIL

Streams play a key role in the global biogeochemical cycles, processing material from adjacent terrestrial systems and transporting it downstream. However, the drivers of stream metabolism, especially those acting at broad spatial scales, are still not well understood. Moreover, stream metabolism can be affected by hydrological changes associated with seasonality, and thus, assessing the temporality of metabolic rates is a key question to understand stream function. This study aims to analyse the geographical and temporal patterns in stream metabolism and to identify the main drivers regulating the wholeecosystem metabolic rates at local and regional scales. Using a coordinated distributed experiment, we studied ten headwaters streams located across five European ecoregions during summer and fall 2014.We characterized the magnitude and variability of gross primary production (GPP) and ecosystem respiration (ER) with the open-channel method. Moreover, we examined several climatic, geographical, hydrological, morphological, and physicochemical variables that can potentially control stream metabolic rates. Daily rates of stream metabolism varied considerately across streams, with GPP and ER ranging from 0.06 to 4.33 g O2 m?2 d?1 and from 0.72 to 14.20 g O2 m?2 d?1, respectively. All streams were highly heterotrophic (P/R < 1), except the southernmost one. We found that the drier climates tended to have the highest GPP, while humid regions presented the highest ER. Between the sampling periods no statistical differences were found. Partial-least squares models (PLS) explained ?80% of the variance in GPP and ER rates across headwater streams and included both local and regional variables. Rates of GPP varied primarily in response to the local variables, such as streambed substrate and stream water temperature. In contrast, regional variables, such as the mean annual temperature or the land use of the catchment, had more relevance to explain ER. Overall, our results highlight that stream metabolism depends on both local and regional drivers and show the positive experience of a young network of researchers to assess scientific challenges across large-scale geographic areas.Los ecosistemas fluviales tienen un papel relevante en los ciclos biogeoquímicos globales, ya que procesan el material de la cuenca y lo transportan río abajo. Sin embargo, los factores que afectan al metabolismo, especialmente aquellos que actúan en una escala espacial más amplia, todavía no se conocen completamente. Además, el metabolismo fluvial puede variar a causa de cambios hidrológicos relacionados con la estacionalidad; lo que también hace importante incluir la variabilidad temporal para entender el funcionamiento de los ríos. Mediante el uso de un experimento distribuido y coordinado, estudiamos diez ríos de cabecera localizados a lo largo de cinco ecoregiones europeas durante verano y otoño del 2014. Se midió la magnitud y la variabilidad de la producción primaria bruta (PPB) y la respiración ecosistémica (RE) mediante el método de canal abierto. Así mismo, se examinaron los factores climáticos, hidrológicos y físico-químicos que potencialmente pueden afectar las tasas metabólicas fluviales. Las tasas diarias de metabolismo fluvial variaron considerablemente entre ríos, con valores de PPB de entre 0.06 a 4.33 g O2 m-2 día-1, y de RE de entre 0.72 a 14.20 g O2 m-2 día-1. Todos los ríos fueron altamente heterotróficos (P/R < 1), excepto el río más meridional. Se observó que los climas secos tendían a tener mayor PPB y las regiones húmedas tendían a tener una mayor RE. No se encontraron diferencias estadísticas entre los períodos de estudio. Los modelos de regresión de mínimos cuadrados parciales (PLS) explicaron --80% de la varianza de PPB y RE para los ríos estudiados. Las tasas de PPB variaron principalmente con factores locales como el sustrato del lecho del río y la temperatura del agua. En cambio, las tasas de RE estuvieron estrechamente relacionadas con factores regionales, como la temperatura media anual y los impactos en la cuenca. En conjunto, nuestros resultados resaltan la necesidad de incluir la escala local y regional en el estudio del metabolismo fluvial y muestran la experiencia positiva de una red coordinada de jóvenes investigadores para lograr retos científicos de amplia escala geográfica.We thank the support of the AIL board throughout the development of the project and all the affiliated institutions for the accessibility of laboratory premises, especially the Limnology Department of Uppsala University and the Department d’Ecologia of the Universitat de Barcelona. We greatly thank all the extended team of participants for their valuable contribution in DOMIPEX project. The authors were supported by the following founding: NC by Wenner-Gren foundation stipend (Sweden, 2014-2016) and a Juan de la Cierva grant (FJCI-2014-23064), EE by a pre-doctoral grant from the Basque Government (2014-2017), AGB by a Swedish Research Council grant (SMAREF 2014-2016), PRL by a Ramón Areces Foundation Postdoctoral Scholarship AM by the Univ. of the Basque Country, AMGF and SP by pre-doctoral research grants from the Spanish Ministry of Economy and Competitiveness (Ref: BES-2013-065770, Ref: BES-2012-059743, respectively), and RR by the IMDEA-Water Institute. DOMIPEX project was founded by the First Call of Collaborative Projects among Young Researchers of the Iberian Association of Limnology (AIL; 2013-2015)

Early-Career Coordinated Distributed Experiments: Empowerment Through Collaboration

Este artículo contiene 7 páginas, 1 tabla, 3 figuras.Coordinated distributed experiments (CDEs) enable the study of large-scale ecological patterns in geographically dispersed areas, while simultaneously providing broad academic and personal benefits for the participants. However, the effective involvement of early-career researchers (ECRs) presents major challenges. Here, we analyze the benefits and challenges of the first CDE exclusively led and conducted by ECRs (i.e. ECR-CDE), which sets a baseline for similar CDEs, and we provide recommendations for successful CDE execution. ECR-CDEs achieve most of the outcomes identified in conventional CDEs as well as extensive benefits for the young cohort of researchers, including: (i) receiving scientific credit, (ii) peer-training in new concepts and methods, (iii) developing leadership and communication skills, (iv) promoting a peer network among ECRs, and (v) building on individual engagement and independence. We also discuss the challenges of ECR-CDEs, which are mainly derived from the lack of independence and instability of the participants, and we suggest mechanisms to address them, such as resource re-allocation and communication strategies. We conclude that ECR-CDEs can be a relevant tool to empower ECRs across disciplines by fostering their training, networking and personal well-being.The authors were supported by the following founding: NC the support of the Beatriu de Pinós postdoctoral program of the Government of Catalonia’s Secretariat for Universities and Research of the Ministry of Economy and Knowledge (BP2016- 00215), EE by a predoctoral grant from the Basque Government (2014-2017), AB by a Generalitat de Catalunya—Beatriu de Pinós (BP-00385-2016), AMG-F by a predoctoral research grant (BES-2013-065770) from the Spanish Ministry of Economy and Competitiveness, MAr by a postdoctoral grant from the Basque Government, MIA by a Juan de la Cierva postdoctoral grant (FJCI-2015-26192), PR-L by a Margalida Comas postdoctoral contract (PD/031/2018) funded by the Government of the Balearic Islands and the European Social Fund, AP by a Ramón Areces Foundation Postdoctoral Scholarship, and AL by a Kempe Foundation stipend. DOMIPEX project was founded by the First Call of Collaborative Projects among Young Researchers of the Iberian Association of Limnology (AIL; 2013-2015).Peer reviewe

Famílies botàniques de plantes medicinals

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia, Assignatura: Botànica Farmacèutica, Curs: 2013-2014, Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són els recull de 175 treballs d’una família botànica d’interès medicinal realitzats de manera individual. Els treballs han estat realitzat per la totalitat dels estudiants dels grups M-2 i M-3 de l’assignatura Botànica Farmacèutica durant els mesos d’abril i maig del curs 2013-14. Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pel professor de l’assignatura i revisats i finalment co-avaluats entre els propis estudiants. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica