Content of lectures: 1. Introduction and fundamentals of hydrology - fluvial ecosystem definition, fluvial hierarchy and longitudinal patterns: zonation and the river continuum; water cycle and water balance, discharge and flow velocity; hydrograph: flood hydrograph, the likelihood of extreme events, minimum discharge, N-year discharge; effect of land use on streamflow. 2. Fluvial geomorphology and sediments - stream channel and valley, sinuosity and meander formation, riffle-pool sequence; sediments - bed sediment composition, sediment transport: sediment load and stream capacity; erosion and deposition, fluvial processes along the river continuum. 3. Influence of flow and bed sediment on the biota - quantification of flow conditions, responses of organisms to flow conditions, flow condition complexity, negative effects of flow and flow refugia, catastrophic drift; substrate heterogeneity and permeability, substrate types and association of benthic organisms with substrate. 4. Primary producers - benthic algae and controlling factors, temporal and spatial variation; phytoplankton (potamoplankton): effect of flow and turbidity; macrophytes: limiting factors, microhabitat modification, common macrophyte species. 5. Detrital energy sources - decomposition of CPOM and the role of bacteria, fungi and invertebrates; sources and decomposition of FPOM; sources of DOM a its incorporation in food webs - biofilms and bakterioplankton. 6. Hyporheic zone - habitat definition and sampling methods, definition of hyporheos; surface-groundwater exchange, throughflow, sediment structure, vertical changes; hyporheic zone as refugium; retention time, nutrient spiralling and bacterial activity; living conditions and the roles of hyporheos. 7. Trophic relationships - functional feeding groups (FFgs), microbial food web, the role of meiofauna in lotic food webs; trophic roles of invertebrates and fish; distribution of food sources and FFgs along the river continuum. 8. Primary consumers - herbivory: assimilation efficiency, grazer responses to food supply, grazer effects on periphyton, effects of disturbances; detritovores: leaf litter palatability and digestion, xylophagy; filtering collectors: mechanisms and selection of particle size, faecal pellet production; gathering collectors. 9. Secondary consumers and species interactions - predation: fish and invertebrate predators, feeding preferences, predation rate, prey susceptibility, effects of predation on prey populations and individual fitness, trophic cascades; competition: exploitation, aggression, resource partitioning and segregation, experimental evidence of competition. 10. Production and stream metabolism - production vs. productivity vs. turnover; primary production, comparison of FFGs and habitats, effect of food supply and temperature, contribution of hyporheic zone, Allen's paradox; benthic respiration and its measurement, gross and net production, organic matter budget, P/R ratio, stream ecosystem efficiency. 11. Lotic communities - drift: behavioural drift, colonization cycle; patterns of regional and local diversity; community structure: core community, species turnover, habitat template, species traits; metacommunities: deterministic and stochastic processes, effects of the stream network, disturbances and history. 12. Habitat alterations - main threats and their consequences; damming: alteration of hydrologic and thermal regime, ecological impacts of dams; ecological impacts of channelisation, morphological degradation of streams in CZ; land-use changes: examples of ecological impacts, changes in CZ since the half of 19th century; stream restoration: goals and methods, situation in CZ, examples from Europe.
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The course purpose is to provide an introduction into the ecology of streams, which are important freshwater ecosystems with key influence on human environment, landscape, and water quality. The course provides information on main relevant topics, including abiotic conditions and geomorphology, trophic relationships of lotic species, species interactions, diversity and antropogenic impacts.
Students learn and understand basic knowledge on environmental conditions, resources and processes that determine the functioning of a stream ecosystem. They understand the basic processes that affect aquatic communities in streams.
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