Universitat de Barcelona
Mostrando ítems 38-57 de 80
Helerotrophic (cetoenzymatic and respiratory activities) and autotrophic (photosynthetic activity) metabolism on epilithic strearn biofilms have been measured, analyzed and studied in this thesis.<br/><br/>The main objective ...
L'abril de 1998, durant l'accident miner d'Aznalcóllar, més de 6 milions de m3 de llots i aigües àcides altament contaminades amb metalls pesants van ser vessats al riu Guadiamar (Sevilla), destruint els ecosistemes fluvials ...
The studies presented in this thesis focus on the biogeochemistry of dissolved organic matter (DOM) in an intermittent stream in a Mediterranean climate zone, with great emphasis on extreme hydrologic events: floods and ...
Habitats commonly occur as more or less interconnected patches constituting spatial heterogeneous mosaics. Connectivity and interactions among habitats can determine their functioning. Therefore, ecological patterns and ...
Aquatic systems are under pressure from multiple stressors that affect the structure, the functioning, and the health of species, communities and ecosystems. One of the main human pressures affecting the Earth’s ecosystems ...
This work is the result of a search for general (or nearly general) regularities at ecosystem level, and an exploration of their practical relevance in our relations with the environment.<br/>I began by adding some new ...
El mejillón cebra, Dreissena polymorpha (Pallas, 1771), es conocido por ser una de las especies invasoras de agua dulce más dañinas, tanto desde el punto de vista ecológico como económico, a nivel mundial. Este exitoso ...
“Lake macroinvertebrates and the altitudinal gradient in the Pyrenees [Los macroinvertebrados lacustres y el gradiente altitudinal en los Pirineos]” is a thesis about freshwater macroinvertebrate communities inhabitting ...
Overall, this thesis is an attempt at approaching seagrass ecosystems from a landscape perspective, with the aim of increasing knowledge about the processes generating patterns at large spatial scales, and understanding ...
ENGLISH ABSTRACT:<br/><br/>The general aim of this thesis was to develop a theoretical framework in order to study large-scale animal movements and/or dispersal processes as random search strategies. The framework was ...
La major part de la concentració de carboni i nitrogen que arriba al Mediterrani des de l'Ebre és en forma dissolta, mentre que en el cas del fòsfor la concentració en la forma particulada pot ser més important, especialment ...
La disponibilidad y calidad del agua que se encuentra en los embalses depende de factores relacionados directamente con las características de la cuenca a la que pertenece el río embalsado, como las cargas de nutrientes ...
La revaluació a gran escala espacial (> de 300 Km) i mitjançant mètodes de quantificació directa, del impacte de l'herbivorisme en els ecosistemes de <i>Posidonia oceanica</i> va revelar pèrdues de biomassa foliar molt ...
The Mediterranean Basin is a climate-change hotspot of the world. Predicted reductions in annual precipitation, increases in mean temperature, and increases in the variability and occurrence of extreme droughts and heat ...
El estudio de los microorganismos en cultivo puro ha propiciado el desarrollo de la genética, la bioquímica y la biotecnología. Sin embargo, la ecología ha permanecido reticente a incorporar a los microorganismos en su ...
The main goal of this PhD thesis was the study of the ammonium oxidation process in high nutrient loaded urban streams. We aimed to unveil regulating factors and driving mechanisms from the organisms to the ecosystem scales ...
Se han realizado diferentes campañas en el tramo estuarino del Río Ebro para estudiar las condiciones estacionales del estuario y la pluma (CyTMAR, Comisión Interministerial de Ciencia y Tecnología, proyecto MAR96-1856, ...
The Systems Approach Framework (SAF) is a methodological framework designed to enhance the efficacy of human decision-making processes within social-ecological systems with regard to sustainability. The SAF was applied in ...
Se estudia por vez primera la morfología de todas las superficies de agua con al menos media hectárea de todo el Pirineo. Caracterizamos morfométricamente estos lagos en base a variables tradicionales, medidas en la ...
The amount of dissolved inorganic nitrogen delivered to streams and groundwater has substantially increased in the last decades due to anthropogenic impacts. This fact has stimulated research on processes related to the ...
