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El acompañamiento y el seguimiento académico de los estudiantes son tareas de gran importancia, necesarias para garantizar el éxito de su carrera profesional durante su vida universitaria, y después de ésta. Estos procesos no comienzan necesariamente con el ingreso de los estudiantes en la Universidad, sino que se extienden a los estudiantes de último curso de educación secundaria y bachillerato. Existe por tanto la necesidad de incluir dentro de las acciones que realizamos en la facultad (información, formación, inclusión) a los estudiantes de bachillerato, dándoles a conocer nuestro entorno de cara a su incorporación en la facultad. Por otro lado, la experiencia del equipo que trabajará en este proyecto, nos ha llevado a ser conscientes de los innumerables problemas que tienen los estudiantes de nuestra facultad para obtener información, formación, acompañamiento, seguimiento o inclusión en cuestiones que pueden afectar de una forma directa en sus actividades académica cotidianas y en su formación integral que reciben en nuestra facultad. La falta de una unidad o servicio centralizado para satisfacer estas necesidades ha sido aún más patente desde la pandemia. En la Facultad de Ciencias Biológicas se realizan multitud de actividades relacionadas con estas iniciativas y que son desconocidas por gran parte de la comunidad universitaria. Las acciones que se vienen realizando desde la facultad de Ciencias Biológicas estas dispersas entre distintos servicios y vicedecanatos (Vicedecanato de Calidad, Innovación y Sostenibilidad, Vicedecanato de Estudiantes, Practicas Externas y Movilidad, Vicedecanato de Estudios, Coordinadora de Grado, Oficina Erasmus, Vicedecanato de Investigación, Secretaría Académica, Delegación de Estudiantes, Oficina de Diversidad, etc.). En este sentido, con este proyecto pretendemos potenciar, sincronizar, coordinar y dar visibilidad a todas estas, mostrando la inmensa utilidad que suponen para nuestros estudiantes, cómo influyen en la mejora de

2023 Acuerdos transformativos CRUE, Invasive species control management involves a large amount of plant material. The present work evaluated the allelopathic potential of the invasive species Ulex europaeus L. (Fabaceae) or ‘Gorse’ and its possible use as a bioherbicide, taking advantage of the extracted plant material after control measures, particularly needed in invaded areas. Specifically, we investigated the efficacy of dried plant material from U. europaeus in the control of the adventitious plants, Lolium multiflorum Lam. and Lolium rigidum Gaud., using the Avena sativa L. crop as a case study. We only used vegetative plant parts because it is essential to avoid the dispersion of U. europaeus with its use, especially in invaded areas. A greenhouse pot experiment was conducted, using activated carbon (AC). The target species (L. multiflorum, L. rigidum and A. sativa) were subjected to a mixture of organic substrate with U. europaeus mulch applied pre-emergence and a subsequent application of aqueous extracts from the mulch. Emergence, height and biomass of the target species were determined. After 2 months, we also tested a possible legacy effect of the substrate on the germination of the target species. We noticed a negative effect of U. europaeus mulch on the emergence of L. rigidum, which can be attributable to the allelopathic compounds released from U. europaeus mulch because the effect was non-significant in presence of AC. Conversely, no effect on L. multiflorum or A. sativa was produced by mulch treatments. Nevertheless, the combination of U. europaeus mulch and its extracts demonstrated a phytotoxic effect on the biomass of the crop species A. sativa, and a fertilizing effect on the weeds L. multiflorum and L. rigidum, which is why this use is discouraged. With our results we cannot recommend the use of U. europaeus as a bioherbicide in oat crops, but this study emphasizes the capability of U. europaeus to structure plant communities through the chemic- and bio-properties of its tissue, Comunidad de Madrid, Universidad Complutense de Madrid, Banco Santander, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Depto. de Biodiversidad, Ecología y Evolución, Fac. de Ciencias Biológicas, TRUE, pub, APC financiada por la UCM

Se presenta la memoria del Proyecto de Innovación docente titulado Seguimiento de los efectos del cambio climático en el Campus. En este proyecto se desarrollan tres objetivos: 1) Capacitar al estudiante a la obtención de datos con validez científica, comprometiéndose con la toma cuidadosa y estandarizada de mediciones que permitan un análisis fiable y repetible, mientras realizan trabajo en equipo; 2) Reforzar el posicionamiento de la Ecología como ciencia que se basa en datos para la elaboración de hipótesis y el rechazo o apoyo a las predicciones que se deriven de estas hipótesis. Se trata de evitar que dogmaticen la teoría y vean los conceptos de la asignatura ligados a la realidad observable; y 3) Enseñar diversas técnicas de medición que no son aplicables para los grupos grandes que manejamos en las prácticas.

Atmospheric nitrogen (N) inputs in the Mediterranean Basin are projected to increase due to fossil fuel combustion, fertilizer use, and the exacerbation of agricultural production processes. Although increasing N deposition is recognized as a major threat to ecosystem functioning, little is known about how local environmental conditions modulate ecosystem function response to N addition, particularly in the context of Mediterranean-Basin ecosystems. Here, we assess how N addition affects important ecosystem properties associated with litter decomposition, soil physical-chemical properties, soil extracellular enzymatic activity and microbial abundance across three long-term N addition experimental sites in the Mediterranean Basin. Sites were located in El Regajal (Madrid, Spain), Capo Caccia (Alghero, Italy), and Arrábida (Lisbon, Portugal) and are all representative of Mediterranean shrublands. No common pattern for litter decomposition process or other studied variables emerged among the control plots of the studied sites. Nitrogen supply only affected soil pH, a major driver of decomposition, in two out of three experimental sites. Moreover, when we explored the role of N addition and soil pH in controlling litter decay, we found that the effects of these factors were site-dependent. Our results point out to local ecosystem features modulating N addition effects in controlling litter decomposition rates in Mediterranean ecosystems, suggesting that the responses of soil functioning to N deposition are site-dependent. These findings provide further knowledge to understand contrasting ecosystem responses to N additions based on a single field experiments.

Soil nitrogen (N) availability is a key driver of soil-atmosphere greenhouse gas (GHG) exchange, yet we are far from understanding how increases in N deposition due to human activities will influence the net soil-atmosphere fluxes of the three most important GHGs: nitrous oxide (NO), methane (CH) and carbon dioxide (CO). We simulated four levels of N deposition (10, 20 and 50 kg N ha yr, plus unfertilised control) to evaluate their effects on NO, CH and CO soil fluxes in a semiarid shrubland in central Spain. After 8 years of experimental fertilisation, increasing N availability led to a consistent increase in NO emissions, likely due to simultaneous increases in soil microbial nitrification and/or denitrification processes. However, only intermediate levels of N fertilisation reduced CH uptake, while increasing N fertilisation had no effects on CO fluxes, suggesting complex interactions between N deposition loads and GHG fluxes. Our study provides novel insight into the responses of GHGs to N deposition in drylands, forecasting increases in NO emissions, and decreases in CH uptake rates, with likely consequences to the on-going climate change.

Upper reaches of temperate streams and oligotrophic lakes depend trophically on the organic matter coming from the surrounding watershed. These aquatic ecosystems accumulate particulate and dissolved organic matter, and chemical compounds liberated from decomposing leaves or from the leachates of leaf litter. These materials supply a wide range of chemical compounds, which may serve as food, but also cause ecotoxicological effects on aquatic organisms. However, this ecotoxicological risk has been amply ignored, especially for freshwater invertebrates. The aims of our study are: (1) to assess the direct toxicity of aqueous extracts of leaf litter from two native (Populus alba, Fraxinus angustifolia) and two tree species exotic to Europe (Robinia pseudoacacia, Ailanthus altissima) on a pelagic and a benthic species of model aquatic invertebrates: Daphnia magna (Cladocera) and Potamopyrgus antipodarum (Mollusca) and (2) to estimate the ecotoxicological risk of the leaf litter extracts to lacustrine ecosystems using different simulated scenarios of shallow lakes. For both invertebrate species, we assessed the effective concentration of leaf extract causing an effect on 50% of the population (EC50) by means of laboratory bioassays. Our results show that the extracts of leaf litter from all the tested trees have a potential ecotoxicological risk in some scenarios, which is independent from the geographic origin of the tree species

Decomposing litter is regarded as the most important source of allelochemicals released into soil. In this study, a greenhouseexperiment was designed to assess the net effect of differently aged leaf litter from exotic (Ailanthus altissima, Robinia pseu-doacaciaandUlmus pumila) and native riverine trees (Populus alba, Populus nigraandUlmus minor) on the germination andgrowth of three herb species (Trifolium repens, Dactylis glomerataandChenopodium album). We also characterized the chem-ical composition of litter samples at different litter ages (0, 1, 2 and 3 months) based on phenolic compounds,fibers and ergos-terol (as a measure of fungal biomass) contents. Overall, litter from both native and exotic species had a negative effect onshoot and root growth of target species, indicating that phytotoxic effects of litter predominate over positive effects. The inhibi-tion effect of the exotic species was similar or even lower than that of the natives, which does not support the Novel WeaponsHypothesis. Among exotic trees,U. pumilashowed the highest inhibition effect on the growth of the target species.T. repenswas the most sensitive target species. The importance of litter age varied with both target and donor species. In general,D.glomeratawas more inhibited by fresh litter,C. albumby half-decomposed litter ofU. pumilaandR. pseudoacaciaand byfresh litter ofA. altissimaandT. repenswas more inhibited by fresh litter ofA. altissimaandP. albaand by highly decomposedlitter ofU. minor. The concentration of total phenolics andflavonoids decreased while acid detergentfiber, lignin and ergosterolincreased with increasing litter age. Hydroxybenzoic and protocatechuic acids and theflavonoid quercetin were detected in alllitter species and at most of the litter ages, while gallic, chlorogenic, vanillic, coumaric and rosmarinic acids were species-spe-cific and they were only detected in fresh litter. Ergosterol concentration appeared as the strongest constrictor of inhibitoryeffect

El proyecto de innovación INNOVA-Docencia Patrimonio académico como herramienta para el desarrollo de futuras carreras científicas-2 tiene como objetivo la continuación del estudio de los modelos anatómicos creados por el Dr. Auzoux para fin didáctico en los contextos universitarios y de enseñanza secundaria a través de la colaboración de distintos profesionales. El primer proyecto se centró en el estudio de modelos de anatomía comparada de zoología custodiados en los museos del Instituto de Educación Secundaria San Isidro y la Facultad de Veterinaria de la UCM. En este proyecto nos centramos en los modelos de anatomía comparada humana custodiados en toda la Universidad Complutense de Madrid y, en concreto, en la Facultad de Ciencias Biológicas, donde entre las ricas y variadas colecciones destaca el modelo clástico de un hombre a pequeña escala, objeto en torno al cual se organizó el proyecto. Un equipo formado por docentes, estudiantes, investigadores y técnicos realizó un amplio estudio para mostrar su procedencia, método de fabricación y uso didáctico; así como su relevancia patrimonial. Gracias también a este proyecto, el modelo ha sido restaurado mejorando su estado y legibilidad. Con esta iniciativa se pretende suscitar el interés por el patrimonio académico y ayudar a su conservación. Los valiosos materiales didácticos utilizados en el pasado para la enseñanza de las ciencias reivindican su función pedagógica y patrimonial dentro y fuera del contexto educativo.

Although anthropogenic nitrogen (N) deposition has been identified as a major threat to biodiversity and ecosystem functioning in Mediterranean environments, little is known on the role of soil properties and microbial attributes in mediating the response of soil organic matter (SOM) decomposition to N inputs. Here, we used Structural Equation Modeling (SEM) to evaluate the direct and indirect effects of N inputs on SOM decomposition rates across different N loads and three Mediterranean semi-arid ecosystems. Our SEM showed that soil ammonium availability decreases soil pH leading to a reduction of the fungi/bacteria ratio and to an increase in soil enzymatic activity, whereas it also has a negative direct and mayor effect on soil decomposition rate. This increase in soil enzymatic activity, which was conditioned not only by soil pH but also by the fungi/bacteria ratio and inorganic N content, had a positive direct effect on the soil decomposition rate. Together, our results suggest that changes in soil properties and microbial attributes linked to N additions can affect the SOM decomposition rates across three regions from the Mediterranean Basin. These findings improve our understanding of the links between soil chemical properties, microbial communities and function in Mediterranean ecosystems, especially in the context of anthropogenic N enrichment.

Nitrogen (N) deposition due to anthropogenic pollution is a major driver of the global biodiversity loss. We studied the effect of experimental N and phosphorus (P) fertilization (0, 10, 20, and 50 kg N ha¿1 year¿1 and 14 kg P ha¿1 year¿1 over the background deposition levels) on plant cover dynamics of a rosemary (Rosmarinus officinalis L.) shrubland after 8 years of nutrient addition in a semiarid Mediterranean ecosystem from Central Spain. We specifically aimed at testing whether N deposition has the potential to influence the observed expanding trend of woody vegetation into areas dominated by grassland, biological soil crusts, and bare soil. Our results show that N addition loads above 10 kg N ha¿1 year¿1 reverted the cover dynamics of shrubs. Under N addition conditions, N was no longer a limiting nutrient and other elements, especially P and calcium, determined the seasonal growth of young twigs. Interestingly, N fertilization did not inhibit the growth of young shoots; our estimates point to a reduced rosemary leaf lifespan that is driving individuals to death. This may be triggered by long-term accumulation of N compounds in leaves, suggesting the need to consider the old organs and tissues in long-lived perennial plants, where N toxicity effects could be more mediated by accumulation processes. Shrublands are a widely distributed ecosystem type in biodiverse Mediterranean landscapes, where shrubs play a key role as nurse plants. Therefore, the disappearance of shrublands may accelerate the biodiversity loss associated with other global change drivers, hamper the recruitment of seedlings of woody species, and, as a consequence, accelerate desertification.

Aims: Nitrogen (N) deposition is a major driver of global change that can influence soil seed bank composition and abundance and seed germination. We investigated how eight years of simulated N deposition impacted the soil seed bank of a semiarid Mediterranean shrubland in Central Spain., Methods: The soil seed bank used in this study was collected from a kermes oak thicket located in the Nature Reserve El Regajal-Mar de Ontígola (Central Spain, 4o9’N, 3o29’W). Samples were collected on September 2014, following the spring/summer seed rain and prior to the onset of equinoctial rains. Consequently, we collected both transient and permanent seed banks without distinction. Three soil cores, 4.5 cm diameter and 4.0 cm deep, were collected from each of 24 plots that are fertilized since October 2007 (72 cores). Fertilization treatments corresponded to simulated N deposition rates of 0, 10, 20 and 50 kg N ha-1 year-1. Soils were incubated under semi-controlled conditions in a greenhouse and emerged plants were recorded., Results: During the course of the study, a total of 198 seedlings belonging to 21 species were recorded. When the number of germinated plants were compared among N treatments no significant differences were found (p<0.05). However, when the between-plot variations in soil variables were considered in the analysis, the highest N treatment had a significantly lower number of germinated seeds than the control (p<0.05). Soil organic matter, organic nitrogen and total nitrogen content masked the effects of nitrogen deposition on soil seed bank., Conclusions: N deposition can influence the emergence of soil seed bank species. However, the mechanism linked to this effect, alteration of seed emergence physiology or compositional shifts of the seed bank, remains unknown.

1 Quercus coccifera, a slow-growing, evergreen oak, grows in contrasting environments in the Mediterranean Basin. Habitat-based selection may have promoted divergence between populations with respect to phenotypic plasticity and genetic variability. 2 We tested the hypothesis that populations of the Q. coccifera originating from a rock outcrop, a continental garrigue formation and an oceanic forest would differ in their plastic response to light intensity. Plants from these populations were grown from acorns in a common garden at 100% and 20% full sunlight. Light response analysis was based on photochemical efficiency, xanthophyll pool, nutrient allocation, growth, crown architecture and light absorption. 3 Light-responsive characters ranged from the subcellular to the whole-plant level. The greatest divergences between sun and shade phenotypes were observed in leaf size, leaf angle and leaf area ratio. However, plasticity in these traits depended on plant provenance. 4 Regardless of the level of organization, populations were invariably ranked in the same order of plasticity when averaged over light-responsive features, with plants originating from the rock outcrop showing the least plasticity and those from the forest the largest. The forest population also had the greatest genetic variability with respect to the isoperoxidase polymorphism. 5 Among populations, plants originating from the phosphorus-deficient rock outcrop contained 30% more P per unit dry weight. Plants from the forest population had 5% more photoprotective xanthophylls, 30% larger total leaf area, with less lobed and larger leaves and a differential plasticity in leaf azimuth. 6 Differences among populations suggested ecotypic differentiation towards less phenotypic plasticity in the most homogeneous light environments. The ecological breadth of the species seemed to be derived not only from its tolerance of Mediterranean conditions but also from the specialization of its populations in contrasti