Aquatic ecosystems are intrinsically complex because they have a network structure and nonlinear processes often take place at various spatial and temporal scales. Nonlinear reactions can occur, for example, as a result of perturbations that trigger a so-called regime shift, such as prolonged drought. Important determinants of complex aquatic ecosystems are the landscape structure in which the water bodies are located and the connectivity, i.e. the interconnection of the water bodies at different levels: These include the flows of water, energy, information, nutrients and pollutants, and the dispersal of organisms. These processes determine the structure and dynamics of ecosystems and are changed over time by external factors such as land use and climate change.
In the programme area “Dimensions of complexity of aquatic systems”, IGB aims to gain a better understanding of the dynamics and functioning of aquatic systems and the living organisms within them. Its overall goal is to enhance our mechanistic understanding on how freshwater ecosystems function and to study their spatial and temporal scaling. An important focus is on the interfaces and interactions between terrestrial and aquatic habitats, between sediment and the water column, between water and air, and between and within organisms.
Speakers
News
Events
Downloads
Selected publications
Effects of temporary streamflow interruption on hyporheic oxygen dynamics
This study provides high-resolution, field-based evidence of the importance of accounting for short-term flow interruptions in river management strategies. It demonstrated that a one-day streamflow interruption of the side channel of the River Erpe caused a significant decrease in diel surface water oxygen amplitude and porewater oxygen concentrations, as well as a metabolic shift after rewetting.
Enhancement of Hyporheic Flow and Solute Transport by Random Burrow- and Mound-Induced Bioturbation
This study examined how bioturbation alters sediment structure and surface roughness, and how this influences hyporheic exchange and biogeochemical processes. It reveals that irregular burrow galleries promote deeper and spatially heterogeneous solute penetration by generating tortuous and highly connected flow paths within the sediment.
A Novel In Situ Experimental Setup for Studying the Impact of Bedform Celerity on 2D Oxygen Distribution in the Hyporheic Zone of Streams
The authors investigated the influence of dynamic hyporheic zones. They developed of a novel field-based setup that enabled the simultaneous monitoring of oxygen dynamics and bedform migration in a stream. Contrary to what has been reported in several studies, they observed more strongly oxygenated bedforms at the highest velocity studied.
Enhancing process interpretation with isotopes: potential discharge-isotope trade-offs in ecohydrological modelling of heavily managed lowland catchments
The authors enhanced a tracer-aided hydrological model to help constrain estimates of ecohydrological partitioning and water balance compartments in sub-catchments of the Middle Spree catchment. They disentangled ecohydrological funtioning in this ET dominated region despite the complexity of the heterogeneous landuse, extensive hydraulic infrastructure and long legacy of intensive management.
Dense stands of aquatic plants retain water in lowland rivers and in adjacent floodplain aquifers
Since the 1980s mean discharge has declined by around 50% and - without aquatic vegetation – also the water level. Dense stands of aquatic plants have kept the water level high in recent summers despite lowered discharge. Most water was retained in adjacent floodplain aquifers rather than in the river channel.