Dr. Aida Viza

Postdoctoral Researcher

Fortstr. 7
Building: I, Room: 0.18
76829 Landau

aida.viza@rptu.de

Research interests

Freshwater ecology, with a focus on intermittent and temporary rivers in Mediterranean region.
Organic matter decomposition and its role in ecosystem functioning under changing hydrological regimes.
Aquatic biodiversity and community responses to environmental variability and climate-related flow alterations.

Project: PostDoc Humboldt fellowship

Leaf litter decomposition under Global Change: Impacts of extreme hydrological events and pesticide pollution across the aquatic-terrestrial continuum

Major questions:

How do hydrological extreme events and pesticide pollution affect litter decomposition and the decomposer communities across aquatic-terrestrial continuum?

This project investigates how extreme hydrological events (floods, hydrological droughts) and pesticide pollution affect litter decomposition and decomposer communities along the aquatic–terrestrial continuum, using mesocosm experiments and fieldwork. In mesocosms, leaf litter from agricultural and forested sites is subjected to simulated floods and drying, both separately and in combination. In the field, litter is exposed to natural conditions in multiple streams over six months. In both approaches, litter is placed in litter bags across three transects (in-stream, shoreline, riparian zone). We will assess decomposition rates and decomposer community composition (microbes and invertebrates). This study integrates freshwater ecology and global change research, providing students with hands-on experience in experimental design, field sampling, and laboratory analyses (e.g. invertebrate identification, molecular tools, decomposition metrics). The results will offer key insights into how climate and human-driven stressors influence essential ecosystem functions, addressing a major knowledge gap regarding global change impacts on boundary ecosystems.

Personal Information

Vita

My research focuses on rivers, particularly temporary ones. During my doctoral thesis, I studied the impact of dry phases and human activities on biodiversity and ecosystem functioning within a Mediterranean catchment, including river stretches inside a natural park and others in agricultural areas. The results showed that the dry phase negatively affected macroinvertebrate diversity and organic matter decomposition. However, factors such as moderate nutrient enrichment, habitat heterogeneity, and tree canopy within the protected area partially mitigated these effects. In ephemeral and highly intermittent rivers, decomposition rates were comparable to those found in terrestrial ecosystems. Headwater rivers and streams within the natural park served as refuges for sensitive taxa and facilitated recolonisation after dry periods. I also examined the functional and taxonomic responses of invertebrates through an experiment and field study, analysing both hyporheic zone communities and those that recovered after the rewetting of dry sediments. This was a pioneering study comparing these refuges with benthic communities under normal flow conditions. The thesis was carried out at the University of Barcelona (UB) with the support of a predoctoral fellowship funded by the Spanish Ministry of Science, Innovation and Universities, as part of a national research project.

Before my PhD, I began my scientific career by collaborating with the FEHM research group at the UB, focusing on the biodiversity of aquatic invertebrates—exploring taxonomic, functional, and genetic diversity, as well as species distribution modelling. In my first article as co–first author, we conducted the first study on the partitioning of intra- and interspecific functional diversity in freshwater invertebrates, measuring over 6,000 stonefly individuals along an altitudinal gradient in the Sierra Nevada. I was also the first author of an article linking phylogenetic and functional diversity to projected climate change responses for 66 Iberian odonate species, based on my Master’s thesis.

I am a member of the Iberian Association of Limnology (AIL), where I have contributed to three collaborative projects within its young researchers’ section, and of the Iberian Rivers Observatory (IberRios), an ecological research network, where I led the first paper of the network.

In addition, I have been involved in local volunteer projects. In science-related activities, I joined the Serralada Litoral Central delegation of the Catalan Institution of Natural History (ICHN), a local research group in my hometown. For seven years, I was part of the editorial board of L’Atzavara, a monographic science outreach journal, where I organised its annual seminar and published two articles across different issues. I have also taken part in public engagement activities, such as the annual mushroom exhibition in Mataró, all supported by the city council.

Publications

See ResearchGate:

Aida Viza

GoogleScholar: