Problem-based learning in a course of Environmental Science and Technology

Uno de los objetivos específicos de la asignatura de Ciencia y Tecnología del Medioambiente (CTMA) del Grado y de Ingeniería Técnica Agrícola es la identificación y la valoración de impactos que ocasionan las diferentes actividades agropecuarias sobre el medioambiente. Tradicionalmente, la forma en la que se ha abordado el estudio de esta parte de la asignatura ha sido a través de clases magistrales. Entre las líneas fundamentales de la adaptación al Espacio Europeo de Educación Superior (EEES) está el cambio de modelos basados en la enseñanza expositiva (enseñanza) a modelos basados en el aprendizaje (alumno). Uno de los métodos de aprendizaje son las técnicas de aprendizaje basadas en el desarrollo de proyectos colectivos “proyect-learning cooperation”. El objetivo de este trabajo fue incorporar la metodología de ‘aprendizaje por proyectos colaborativos’ en la asignatura de Ciencia y Tecnología del Medioambiente. El proyecto consistió en el seguimiento por parte de grupos de alumnos de un ensayo de invernadero de dosis-respuesta, en el que se analizó el efecto producido por el incremento de la dosis de compost (subproducto de actividades agrícolas) sobre dos especies de herbáceas con carácter forrajero. Los diferentes grupos de alumnos tuvieron que realizar una evaluación e identificación de los efectos producidos sobre ambas especies. La valoración de los proyectos realizados por los alumnos se realizó mediante la revisión de los documentos técnicos que se entregarán al profesor, y con una exposición oral de síntesis.One of the specific objectives of the course ‘Environmental Sciences and Technology’ of the Agronomy Degree, is the identification and the assessment of the impacts that agricultural activities cause on the environment. Traditionally, the way it has approached the study of this part of the course is through lectures. An important aspect of the adaptation of higher education to European Higher Education Area (EHEA) is the change of models based on teaching to a model learning-based. One of the methods of learning are the techniques based in the development of collective projects “project-learning cooperation”. The aim of this work was incorporate the project-learning cooperation methodology in the subject ‘Environmental Sciences and Technology’. The project consisted in monitoring a greenhouse experiment (dose-response) by students groups. Each group analyzed the effect of different doses of compost (product of agricultural activities) on two grass species with forage use (including the identification and the assessment of impacts). For review of the success rate achieved in the implementation of this methodology, the student´s projects were revised

Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex

Niche evolution in plant polyploids remains controversial and evidence for alternative patterns has been reported. Using the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×) as a model, we aimed to integrate three scenarios – competitive exclusion, recurrent origins of cytotypes and niche filling – into a single framework of polyploid niche evolution. We hypothesized that high polyploids would tend to evolve towards extreme niches when low ploidy cytotypes have nearly filled the niche space. We used several ecoinformatics and phylogenetic comparative analyses to quantify differences in the ecological niche of each cytotype and to evaluate alternative models of niche evolution. Each cytotype in this complex occupied a distinct ecological niche. The distributions were mainly constrained by soil characteristics, temperature and drought stress imposed by the Mediterranean climate. Tetraploids had the highest niche breadth and overlap due to their multiple origins, whereas the higher ploidy cytotypes were found in different, restricted, nonoverlapping niches. Niche evolution analyses suggested a scenario with one niche optimum for each ploidy, including the two independent tetraploid lineages.Our results suggest that the fate of nascent polyploids could not be predicted without accounting for phylogenetic relatedness, recurrent origins or the niche occupied by ancestors.Aridos La Melera S.L. (FIUS project 2234/0724

Impact of short-term extreme temperature events on physiological performance of Salicornia ramosissima J. Woods under optimal and sub-optimal saline conditions

Increasing extreme temperature climatic events could exert an important effect on plant photosynthetic performance, which could be modulated by the co-occurrence with other environmental factors, such as salinity, in estuarine ecosystems. Therefore, a mesocosm experiment was designed to assess the impact of temperature events for three days (13/5 °C, 25/13 °C and 40/28 °C) in combination with two NaCl concentrations (171 and 1050 mM NaCl) on the physiological performance of Salicornia ramosissima. Extreme temperature events had a negative impact on S. ramosissima photosynthetic efficiency, this effect being more marked with cold wave at both salinities, compared with heat wave, even in presence of NaCl excess. This differential thermotolerance in the photosynthetic apparatus was ascribed to the greater integrity and functioning of its photosynthetic pathway at high temperature, as indicated by constant gs, Vc,max values at optimal salinity and the higher values of those parameters and gm recorded in combination with NaCl excess. Moreover, S. ramosissima was able to upregulate the energy sink capacity of its photochemical apparatus at elevated temperature and salinity by a greater energy excess dissipation capacity. This could have contributed to reducing the risk of oxidative stress, along with the recorded higher capacity for antioxidant enzyme activity modulation under these conditions.España, MINECO Project CGL2016– 75550-

Aplication of active-learning cooperation strategy in the course of Principles, Instrumentation and Methods in Ecology and Soil Science

La sociedad actual requiere la formación de profesionales capaces de integrarse en grupos de trabajo que se autogestionen. Así, dentro del proceso de convergencia universitaria europea destaca como uno de sus objetivos el desarrollo de titulados capaces de integrarse en equipos de trabajo con la capacidad para la construcción individual y colectiva del conocimiento. Un aspecto importante de la adaptación de la enseñanza superior al Espacio Europeo de Educación Superior (EEES) es el cambio de modelos basados en la enseñanza a modelos basados en el aprendizaje. Este trabajo presenta una experiencia en la asignatura de ‘Principios Instrumentación y Métodos en Ecología y Edafología’ del primer curso del Grado en Biología (Facultad de Biología de la Universidad de Sevilla, 2010-2011), sustentada en la metodología del aprendizaje cooperativo entre los alumnos, con un enfoque de aprendizaje basado en problemas. Para obtener una valoración sobre el porcentaje de éxito conseguido en la aplicación de esta metodología se consideraron dos indicadores: 1) grado de asistencia/abandono y de aprobados de los alumnos de la parte práctica de la asignatura y 2) encuesta de satisfacción del alumnado sobre la metodología docente empleada. Con respecto al primer indicador se observó un alto nivel de implicación y compromiso por los alumnos en el proceso de aprendizaje, de forma que los niveles de abandono de la parte práctica de la asignatura fueron mínimos. Por otro lado, más de un 90% de los alumnos que habían optado por la asistencia continúa a las clases y por la participación en las dinámicas de grupo superaron esta parte de la asignatura. Finalmente, existió una valoración muy positiva por parte de los alumnos en la aplicación de este tipo de métodos docentes y los estudiantes fueron capaces de encontrarles numerosos aspectos positivos para su formación.Today's society requires the training of professionals able to integrate into working groups. So within the European university convergence process stands out as one of its objectives the development of graduates capable of integrating into teams with the capacity for individual and collective construction of knowledge. An important aspect of the adaptation of higher education to European Higher Education Area (EHEA) is the change of models based on teaching to a model learning-based. This paper presents an experience in the subject of 'Principles, Instrumentation and Methods in Ecology and Soil Science' of the first year of Biology (Faculty of Biology, University of Seville, 2010- 2011), based on the methodology of cooperative learning among students, with a focus on problem-based learning. For review of the success rate achieved in the implementation of this methodology was considered two indicators: 1) degree of attendance/dropout and students who approved the practice of the subject and 2) Student satisfaction on the teaching methodology used (surveys). Regarding the first indicator was observed a high level of involvement and commitment by students in the learning process. So, the levels of abandonment of the practices subject were minimal. Furthermore, over 90% of students who opted for the assistance continues to classes and participated in group dynamics, exceeded this part of the course. Finally, students were capable of finding many positive aspects for his training and they had a very positive evaluation in applying these types of teaching methods

Polyploidy promotes divergent evolution across the leaf economics spectrum and plant edaphic niche in the Dianthus broteri complex

The evolution of the leaf economics spectrum (LES) is known to be constrained by genetic relatedness but also promoted at small geographical and phylogenetic scales. In those cases, we hypothesized that polyploidy would play a prominent role as an outstanding source of functional divergence and adaptive potential. We registered leaf-level nutrient, water- and light-economy-related traits from the LES as well as edaphic properties in the four cytotypes of the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×). We analysed the effect of ploidy level on the integration of the LES network, checked if concerted evolution occurred between LES and soil niche and tested the influence of phylogeny on the variables. Alternative evolutionary models for both sets of traits were compared. We found higher divergence of polyploids (especially 6× and 12×) compared to diploids in the LES and soil niche, but these traits are not coevolving. 6× and 12× showed opposite ecological strategies regarding resource use and higher uncoupling of the LES network. Early divergence of traits prevailed in both LES and edaphic niche (supported by better fitted evolutionary models with one optimum per cytotype), but post-polyploidization processes played an important role for the photochemical behaviour. Synthesis. Our results indicated shifts in ecological strategies across Dianthus broteri cytotypes and suggested a powerful role of polyploidy in overcoming constraints for the evolution of plant functional traits.PGC2018-098358-B-I00 from the Spanish MICINNÁridos La Melera S.L. (FIUS project 2234/0724

Zinc tolerance and accumulation in the halophytic species Juncus acutus

The research on species with capacity to tolerate and accumulate zinc is of paramount importance for phytoremediation purposes. An experiment was designed to investigate the effect of Zn from 0 to 100mmoll-1 on the growth, photosynthetic apparatus and nutrient uptake of the halophytic species Juncus acutus. Gas exchange, chlorophyll fluorescence and photosynthetic pigments concentration were measured. We also determined total zinc, magnesium, potassium, phosphorus and sodium concentrations, as well as C/N ratio. J. acutus showed high tolerance to Zn-induced stress, since all plants survived and none of them showed any toxicity symptoms, such as chlorosis, necrosis or growth reduction at concentrations up to 100mmoll-1 Zn. The integrity and functionality of the photosynthetic apparatus were unaffected even at zinc concentrations greater than 500mgkg-1 on tillers. Likewise, nutrient absorption was relatively unaffected. Zn tolerance was associated with the capacity to accumulate Zn in roots (with values up to 2500mgkg-1) and largely avoid its transport to tillers. These characteristics, along with its ability to establish in a wide variety of ecosystems, render this species a useful phytostabilizer for revegetation of Zn-contaminated lands

El empleo de técnicas de control y erradicación en la lucha contra especies invasoras: conveniencia de la herbivoría como método de bio-control de la invasión de Spartina densiflora brongn. en el Campo de Gibraltar

Spartina densiflora es una gramínea procedente de Sudamérica que está invadiendo numerosas marismas mareales en el golfo de Cádiz provocando problemas muy graves para la conservación de estos ecosistemas, como la pérdida de biodiversidad. En el Campo de Gibraltar Spartina densiflora se localiza en las desembocaduras de los ríos Vega y Jara y en el estuario del río Palmones. Conocer el estado de la invasión en estas zonas es de especial relevancia a la hora de optar entre diferentes técnicas de erradicación o control. Mientras en el río Palmones sería factible la eliminación mecánica de los clones de Spartina densiflora, en el caso de los estuarios de los ríos Vega y Jara el empleo de la ganadería como medida de bio-control parece la estrategia más aconsejable. No obstante, la amplia gama de efectos que la presión de la herbivoría provoca sobre las comunidades vegetales y, en concreto, sobre la evolución de especies invasoras hace necesario llevar a cabo estudios detallados sobre la utilidad de la ganadería como herramienta de gestión en materia de especies invasoras

Effect of herbicide and soil amendment on growth and photosynthetic responses in olive crops

Diuron [3-(3,4-dichlorophenyl)- = 1,1-dimethylurea] and simazine (6-chloro-N2, N4-diethyl-1,3,5-triazine-2,4-diamine) are soil-applied herbicides used in olive crops. The objective of this study is to investigate the combined effect of these herbicides and the amendment of soil with an organic waste (OW) from the olive oil production industry on the growth and photosynthetic apparatus of adult olive trees and to compare the results with those obtained by Redondo-Gómez et al.[1] for two-year-old trees. For this purpose, growth rate, gas exchange and chlorophyll fluorescence parameters were measured in 38-year-old olive trees, after one and two months of soil herbicide treatment and/or OW amendment. Soil co-application of OW and herbicide increases the quantum efficiency of Photosystem II (PSII) and the assimilation of CO2 in olive trees, which led to a higher relative growth rate of the branches and leaves in length. Herbicide treatment reduced the photosynthetic efficiency in olive trees after two months of soil application, while this reduction is evident from week one in younger trees

Seasonal ecophysiology of an endangered coastal species, the yellow-horned poppy (Glaucium flavum Crantz)

Glaucium flavum Crantz. is a short-lived perennial herb distributed in coastal zones from the Black Sea to southern, western and north-western Europe. Despite its diminishing area of distribution and potential pharmacological value, little is known about the ecophysiological features of this coastal species. We investigated the photosynthetic performance of G. flavum by measuring gas exchange, chlorophyll fluorescence, photosynthetic pigment concentration and leaf water content over the space of a year in a coastal habitat of SW Spain. We also measured the variation in total concentrations of nitrogen, phosphorus, sulphur, potassium, calcium and magnesium, in the leaves and soil, throughout the study period. G. flavum showed a high resistance to summer drought conditions which appeared to be due to the high degree of stomatal control. The potential photochemical efficiency of photosystem II showed minimum values during the winter, indicating that low temperatures can produce negative effects within the photosynthetic apparatus. However, the marked decline in net photosynthesis during the winter seems to be mainly related to a loss of metabolic activity. Although leaf nutrient concentrations were, in general, within the normal ranges, phosphorus availability seems to be limited by the high calcium concentrations detected in the soil of the study site. Our study points out the efficiency of the different physiological adaptations of this rare and endangered coastal species in coping with the strong seasonal variability of the Mediterranean climate.Ministerio de Educación AP2007–04420Junta de Andalucía RMN– 22

Phenotypic diploidization in plant functional traits uncovered by synthetic neopolyploids in Dianthus broteri

Whole-genome duplication and post-polyploidization genome downsizing play key roles in the evolution of land plants; however, the impact of genomic diploidization on functional traits still remains poorly understood. Using Dianthus broteri as a model, we compared the ecophysiological behaviour of colchicine-induced neotetraploids (4xNeo) to diploids (2x) and naturally occurring tetraploids (4xNat). Leaf gas-exchange and chlorophyll fluorescence analyses were performed in order to asses to what extent post-polyploidization evolutionary processes have affected 4xNat. Genomic diploidization and phenotypic novelty were evident. Distinct patterns of variation revealed that post-polyploidization processes altered the phenotypic shifts directly mediated by genome doubling. The photosynthetic phenotype was affected in several ways but the main effect was phenotypic diploidization (i.e. 2x and 4xNat were closer to each other than to 4xNeo). Overall, our results show the potential benefits of considering experimentally synthetized versus naturally established polyploids when exploring the role of polyploidization in promoting functional divergence.España Ministerio de Ciencia e Innovación project POLYTRANSECO (PGC2018-098358-B-I00)Spanish Ministerio de Universidades (FPU19/02936