Now showing items 21-40 of 74

    Els prats de dall de la terra baixa catalana. Caracterització geobotànica, valoració agroambiental i estudi de les relacions fitosociològiques entre els prats dalladors de l'Europa occidental 

    Mercadal i Corominas, Gabriel (Date of defense: 2019-11-13)

    The hay meadows in the Mediterranean region of Catalonia. Geobotanical characterisation, agri-environmental assessment, and study of the phytosociological relationships between hay meadows in Western Europe We locate ...

    Flow alteration and wastewater inputs effects on freshwater communities in Mediterranean rivers 

    Mor Roy, Jordi-René (Date of defense: 2019-09-19)

    Mediterranean rivers are characterized by high hydrological variability and heterogeneity of habitats, placing themselves amongst arid and temperate climates, and are associated with high biological diversity. On the ...

    Multiple stressor effects on river biofilm communities: from community composition to ecosystem processes using experimental mesocosms 

    Romero Blanch, Ferran (Date of defense: 2019-12-20)

    Human exploitation of river ecosystems, together with the increasing pressure that represents climate change, is posing rivers worldwide at risk. In rivers, microorganisms are ecologically very important. Most of ...

    Reproductive and condition status of “cold water” marine fish: new insights from a changing environment 

    Serrat Llinàs, Alba (Date of defense: 2019-04-10)

    Exploited marine fish species with an affinity for cold waters inhabiting close to the warmer edge of their distribution area are exposed to stress caused by fishing and climate change. Three case studies of “cold water ...

    Efectes del canvi global a les rouredes de Quercus petraea al NE de la Península Ibèrica 

    Bou Manobens, Jordi (Date of defense: 2019-04-11)

    The sessile oak Quercus petraea is widespread in Central Europe. The populations in the NE Iberian Peninsula are at the southernmost limit of the species range, in the most Mediterranean-type conditions and at the xeric ...

    Estudio de la red trófica microbiana en lagunas someras: autotrofia versus heterotrofia 

    Àvila Izquierdo, Núria (Date of defense: 2017-05-26)

    Autotrophic and heterotrophic microorganisms are two essential functional units in the microbial food web of aquatic ecosystems. They play a key role in nutrient cycling and carbon flow and influence the structure, composition ...

    Microbial community assembly and biogeography in the Pyrenean lacustrine district 

    Ortiz Álvarez, Rüdiger (Date of defense: 2018-05-18)

    The microbial metacommunity of the Pyrenees mountain range has never been studied at the regional level. In this PhD thesis, the main goal is to describe the taxonomic diversity and reveal the ecological processes (biotic ...

    Arsenic and fluvial biofilms: biogeochemistry, toxicity and biotic interactions 

    Barral Fraga, Laura (Date of defense: 2017-10-26)

    Based on the current knowledge about biofilm ecotoxicology and arsenic biogeochemistry in freshwater ecosystems, this thesis studied, under realistic environmental concentrations, i) the role of benthic biofilms in the ...

    Climate change and Mediterranean ecosystems: plant and soil responses to UV radiation and water availability before and after a perturbation 

    Díaz Guerra, Laura (Date of defense: 2017-07-21)

    Taking into account the expected changes in solar UV levels, precipitation and fire regime in the Mediterranean basin, the main goal of this thesis was to evaluate the effects of UV radiation (UV-A and UV-B) and diminished ...

    Estudi dels patrons de colonització postincendi en vertebrats al llarg de gradients ambientals i espacials 

    Puig-Gironès, Roger (Date of defense: 2016-12-22)

    Wildfires are natural perturbations that affect the structure of the landscape and biodiversity. In the Mediterranean basin, wildfires occur especially in hot seasons. However, in recent years the number of fires with the ...

    Effects of global change on fish assemblages in Mediterranean streams 

    Merciai, Roberto (Date of defense: 2016-09-30)

    L'objectiu d'aquesta tesi és de'explorar alguns aspectes de l'impacte humà sobre les poblacions de peixos i altres components dels ecosistemes fluvials Mediterranis de Catalunya. Es va mostrar com els peixos del Riu Llobregat ...

    Controls on the dynamics of riverine dissolved organic matter: insights from a Mediterranean river network 

    Casas Ruiz, Joan Pere (Date of defense: 2017-05-31)

    In river networks, dissolved organic matter (DOM) constitutes the major pool of organic carbon, and plays a key role as energy source and modulator of toxic substances availability. In this thesis, Joan P. Casas-Ruiz and ...

    Pharmaceuticals and endocrine disruptors: accumulation in aquatic biota and environmental effects 

    Huerta Buitrago, Belinda (Date of defense: 2016-04-12)

    Occurrence, fate, and adverse effects of emerging contaminants in the aquatic environment have become a matter of concern, since these compounds have been persistently detected in wastewater treatment plant (WWTP) effluents, ...

    O potencial didático das imagens geocientíficas em livros de textos do ensino secundário: representação da dinâmica interna da terra 

    Souza, Edson Roberto da (Date of defense: 2015-07-29)

    Dada la importancia de ilustraciones científicas en los procesos de aprendizaje de contenidos geológicos, se investigó posibles relaciones entre su potencial educativo y sus etapas de producción en los libros de texto de ...

    Influences of toxicants on freshwater biofilms and fish: from experimental approaches to statistical models 

    Tuulaikhuu, Baigal-Amar (Date of defense: 2016-06-10)

    The main aims of this thesis are: i) to evaluate arsenic toxicity in two major, interacting components of the freshwater ecosystem, biofilm and fish, to provide information on environmentally realistic exposures and on ...

    Macroalgal-dominated coastal detritic bottoms of the Mediterranean Sea and the Northeastern Atlantic: description, distribution and sampling methodologies 

    Joher Sais, Sergi (Date of defense: 2016-01-14)

    En aquesta tesi es van descriure els principals fons algals del detrític costaner de la plataforma continental de Mallorca i Menorca (illes Balears, Espanya), i es van proposar mètodes efectius per al seu mostreig tant a ...

    Effects of parasitism on the condition and reproductive capacity of three commercially exploited fish species in the Mediterranean Sea 

    Ferrer Maza, Dolors (Date of defense: 2016-02-05)

    This PhD thesis evaluates the links between parasitism, condition and reproduction of mature female individuals of three of the most captured fish species in the western Mediterranean Sea: European hake, Merluccius merluccius; ...

    Towards the implementation of ecosystem management: a multi-level assessment of a small scale Mediterranean multi-specific fishery 

    Dimitriadis, Caterina (Date of defense: 2015-10-16)

    Fisheries are complex systems, in which the process of assessment and management should explicitly consider the ecological, social and economic attributes of the system. For a responsible and sustainable management of ...

    Climate change and the expansion of thermophilic fishes in the northwestern Mediterranean: the importance of studying condition and reproduction to understand the increase in their abundance 

    Villegas Hernández, Harold O. (Date of defense: 2015-09-04)

    A direct consequence of sea warming in the Mediterranean is a increase in the abundance of thermo-tolerant species fish species such as Sphyraena viridensis, Pomadasys incisus, Pomatomus saltatrix and Trachinotus ovatus. ...

    Linking river sediment physical properties to biofilm biomass and activity 

    Ann, Vannak (Date of defense: 2015-06-30)

    River sediments are composed by a variety of grain sizes which determine their permeability and biogeochemistry. The aim of this thesis was to test whether differences in river sediment physical characteristics generate ...