At the Slovenian Water Congress, a report on the importance of biofilm in freshwaters was presented to the expert public. Biofilm, consisting of a complex group of microorganisms and extracellular matrix, in the process of mineralization effectively transforms more complex organic matter into simple inorganic compounds. The greater surface area of the biofilm substrate means greater ability of the self-cleaning system. In the extreme case, when the water flows through the concrete trough or the muddy bottom, this ability is severely curtailed. In the watercourse with a hydrogeomorphologically diverse sandy and pebbled bottom, where water in different areas of entry, it flows for some time between grains of sand and gravel, and then re-emerges from the sediment, and this contact provides complex metabolic pathways leading into cleaner water at the last stage. Hydromorphological interventions in the waterline severely curtail one of the key ecosystem services - contributing to ecosystem relief. This is reflected in the poor quality of both surface and underground waters, which are a source of drinking water. The paper presents various ways of evaluating the activity of biofilm in running waters. In the case of various Slovenian rivers, the latest findings on how the interventions in the riverbed and human activities in the river basin affect the intensity of microbial processes are summarized.
F.18 Transfer of new know-how to direct users (seminars, fora, conferences)
COBISS.SI-ID: 4304975In the climate warming scenario predicted for this century, water temperature and nutrient concentrations are expected to increase while their synergistic effects on the stream metabolism are poorly known. In this study the effects of water temperature and nutrient concentrations on the hyporheic respiration were investigated on sediments collected from pristine and impacted stream reaches. During summer, synergistic effects of T and increased nutrinents were observed at both locations, while during other seasons this was not confirmed, suggesting the seasonal differences in response of biological processes to stressors.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 3960399In the frame of this contribution aquatic geochemistry and isotopic geochemistry of three gravel-bed rivers (River Kamniška Bistrica, River Idrijca and River Sava in Slovenia) in Slovenia is presented. These gravel-bed rivers are severely impacted by a range of simultaneous processes including water pollution, flow and channel alteration, over-fishing, invasive species and climate change. Systematic studies of river water geochemistry provide important information on chemical weathering of bedrock/soil and natural anthropogenic processes that may control the dissolved chemical loads, while the studies of biological components of the river system (macrophytes, periphyton, heterotrophic biofilm, invertebrates, fish) contribute to the understanding how the system response to human impacts by means of both structural characteristics and functional response.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 29338919The conference paper presents the layout of the hydrologic model of the Pesnica River from the source to the Perniško lake, which allows simultaneous modeling of nutrient runoff. To this end, we used a hybrid approach to modeling based on a knowledge library and a tool for automatic detection of equations ProBMoT. Different data were needed for this type of modeling: relief, precipitation, soil use, number of inhabitants, cleaning sites, soil erosibility, etc. The model was calibrated for measurements of the flows and concentrations of nutrients carried out in 2016. The model can be used to determine the contribution of different sources of pollution to the pollution of surface and partly groundwater. The model enables testing of different scenarios (climate change, land use change and changes in waste water discharge) and validation of the performed measurements, for which we have not had adequate tools so far.
F.18 Transfer of new know-how to direct users (seminars, fora, conferences)
COBISS.SI-ID: 8028001In this conference contribution our understanding of relationships and combined effects of various environmental stressors including climate change-induced variations in the Idrijca catchment were presented as a result of modeling efforts, field and laboratory measurements conducted; and how these effects are linked to the ecosystem response in terms of Hg mobility, partitioning and reactivity.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 27857959