Bookofabstracts.Pdf

1 Plenary Sessions 4 Regular and Special Sessions 10 Posters 81 Index of authors 133 2 Plenary Sessions 3 Boyero, Luz Castro, Pilar University of the Basque Country (UPV/EHU) Environmental Sciences and Biology Schools of the University of Alcalá GLOBALSCALE EXPERIMENTS: AN EMERGING TOOL FOR EXPLORING THE FUNCTIONING OF ENVIRONMENTAL IMPACTS CAUSED BY THE FRESHWATER ECOSYSTEMS INVASION OF EXOTIC PLANTS IN RIVERBANKS Individual ecological studies, although suitable for Floodplains have environmental filters which are little testing hypotheses and developing theory, provide site‐ intense for the establishment of vegetal life. In one side, specific information that is difficult to extrapolate to soil resources are abundant, both water and nutrients. provide broad generalizations. Today, emerging globally On the other side, competence is not too intense, thanks relevant questions (e.g., climate change, biodiversity to perturbations that periodic floods cause, clearing loss, invasive species or habitat degradation) require a vegetation and delivering resources for pioneer species. reconsideration of what approaches would be best for If we add anthropic perturbations (such as riparian understanding large‐scale ecological patterns and forest cutting for agriculture, flood regulation, riverbank processes. A technique commonly used for this purpose alterations, etc) and the fact that rivers are efficient is meta‐analysis, a quantitative approach to reviewing, dispersers of all kind of propagules, it is easy to integrating, and summarizing large numbers of understand that these are one of the most propitious independent studies. However, the robustness of a environments for the establishment and propagation of meta‐analysis relies on the individual studies selected exotic plants. The invasion of exotic plants is recognized for inclusion, and issues of scale and methodology as a very important factor of global change, together cannot be controlled retrospectively. An emerging, with the climate change and land use change. In this alternative approach is global‐scale coordinated work we analyze the environmental impacts on rivers experiments, run in parallel by several research groups and riverbanks caused by exotic tree invasions. We in multiple locations around the globe. These focus on the consequences on water and soil matter experiments have the advantage of addressing global cycles caused by the entry of exotic trees leaf trash, and problems and exploring general ecological theory, while how these changes may influence on the taxonomic offering the precision of controlled experiments. We will composition of invertebrates processing this organic review the existing global‐scale experiments conducted matter by freshwater ecologists and discuss the potential of this type of studies for developing ecological theory and advancing our understanding of freshwater ecosystem functioning. 4 Duarte, Sofia Fennessy, Siobhan University of Minho, Portugal Jordan professor of Biology and Environmental Science at Kenyon College University of Guelph, Canada Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) BIOGEOGRAPHY OF STREAMDWELLING U.S. Water Science and Technology Board DECOMPOSER FUNGI: CURRENT KNOWLEDGE AND FUTURE PERSPECTIVES ANTHROPOGENIC STRESSORS AFFECT CARBON Until the recognition of the crucial role that fungi play in STOCKS AND FLUXES IN WETLANDS AT A VARIETY plant‐litter decomposition in streams, limnologists OF SCALES AND REGIONS largely ignored these organisms. In particular, Ingoldian Wetland ecosystems are one of the largest global carbon fungi or aquatic hyphomycetes, abound in well‐aerated sinks holding approximately 30% of the estimated 1,500 waters and are regarded as the dominant fungal Pg of global soil carbon, despite occupying only 5‐8% of decomposers of decaying leaves in streams. The its land surface. Globally, more than half of the predominance of aquatic hyphomycetes on submerged historical wetland area has been lost due to decaying leaves over other fungal groups is mainly anthropogenic activities resulting in a net transfer of attributed to physiological adaptations to fast flowing carbon from the soil to the atmosphere. There have waters. These include: i) the high production rates of been few comprehensive studies to quantify wetland characteristically shaped conidia; tetraradiate or soil carbon stocks over large geographic regions, nor sigmoid types of spores that act as miniature anchors, how human disturbance affect these stocks through arresting on a suitable substratum in rapid flowing processes such as altered rates of soil carbon accretion waters, and ii) the ability to produce a variety of and methane emissions. Here I report on studies extracellular enzymes able to break the major plant conducted in three regions to investigate patterns in soil polysaccharides, which increase litter quality to carbon stocks and fluxes. The Ebro Delta (Catalonia, invertebrate detritivores. Since Ingold’s (1942) initial Spain) is an ecologically important region where description that mycologists have been interested in wetlands are under threat from sea level rise, deciphering global distribution patterns of aquatic subsidence and reduction of fluvial sediment inputs. hyphomycetes. Much of this knowledge emerged from Here rates of C sequestration ranged from 20 to 500 gC species classification based on their characteristic m‐1 yr‐1, with highest rates seen in areas where conidial shapes (morphospecies). Based on data from hydrologic and sediment subsidies were greatest. 352 publications, documenting 335 morphospecies, I Methane emissions were low in salt and brackish sites, will present distribution patterns of aquatic making them net carbon sinks. In the U.S., soil carbon hyphomycetes from studies throughout the world in an data were collected in the National Wetland Condition attempt to better understand the magnitude of global Assessment, a probabilistic, spatially representative species richness, patterns of biodiversity and the extent national survey, to provide unbiased estimates of soil of cosmopolitanism versus endemism, as well as the carbon at the national scale. Carbon stocks varied as a relative influence of contemporary environmental function of location and wetland type, which are factors versus the legacies of historical events on intrinsically linked, and regional carbon densities reflect present‐day distribution patterns. a high degree of variability. Carbon stocks decreased significantly as anthropogenic stressors increased and the deepest soil layers sampled (90‐120 cm) showed the greatest differences in carbon content. These results are compared to mechanistic studies conduced in the Eastern US to identify the factors that affect carbon sequestration along a gradient of human disturbance. Here, as in the Ebro Delta, we found a strong link between land use, hydrologic patterns, and carbon accretion and storage. These C accretion rates were related to changes in land use that that generate and deliver water sediment to down gradient wetland sites. Overall these studies provide a mechanistic explanation of how human activities decrease soil carbon at regional scales. Efforts to protect climate should address the role of wetlands as climate regulators and include measures for the conservation and sustainable management of their carbon stocks . 5 Lupon, Anna Mann, David Universitat de Barcelona IRTA, Programa d’Ecosistemes Aquàtics, Catalunya (España) THE INFLUENCE OF MEDITERRANEAN A QUANTUM LEAP EVERY WHICH WAY? RIPARIAN ZONES ON STREAM NITROGEN UNDERSTANDING THE EXTENT AND ORIGINS OF DYNAMICS MICROALGAL SPECIES DIVERSITY AND THEIR A CATCHMENT APPROACH RELEVANCE IN A CHANGING WORLD. During last decade, anthropogenic activities have doubled the available nitrogen (N) in catchments, Margalef [1972: Trans. Connecticut Acad. Arts & Sci 14: leading to several environmental problems. Within 211] noted that “… the limitation of the human capacity catchments, riparian areas are recognized to be natural to handle diversity probably influences any description filters of N because they can substantially diminish the of nature …” and so the measurement of diversity “... is a delivery of this essential nutrient from terrestrial to function of the beholder as well as of what is measured”. aquatic ecosystems. However, understanding the Certainly this applies to microalgae. While our influence of riparian zones on regulating N export from perceptions of microalgal diversity were based on light catchments still remains a challenge, mainly because microscopical observations of morphology, it seemed stream water chemistry integrates biogeochemical that there were rather few, widely distributed species, processes co‐occurring within upland, riparian, and leading to the idea [cf. R.M. May 1988, Science 241: fluvial ecosystems. In this talk, I will summarize the 1441] that there is a diversity ‘deficit’ that requires results of different empirical and modelling approaches explanation. A series of papers by B.J. Finlay and in order to examine in detail some of the processes and colleagues in the early years of the new millenium mechanisms by which Mediterranean riparian zones can suggested that low diversity and lack of endemism in regulate both stream hydrology and catchment N microalgae and protists might be the consequence of exports. In addition, I will show how the combination of enormous population sizes driving high dispersal rates different catchment pools (soils, groundwater and stream and

Load more