- Department:(Dept. 1) Ecohydrology and Biogeochemistry
Spatial and seasonal patterns of water isotopes in northeastern German lakes
In course of measuring campaigns, the spatial and temporal dynamics of water isotopes in northeastern German lakes were evaluated. The data will serve as basis for further studies, for example with respect to connectivity of lakes and biochemical processes in macrophytes.
Xylem water in riparian Willow trees (Salix alba) reveals shallow sources of root water uptake by in-situ monitoring of stable water isotopes
The authors monitored stable isotopes in-situ at high resolution in soil and plant water at an urban green space to understand the ecohydrological functioning of the Critical Zone, i.e., the thin, dynamic, life-sustaining skin of the Earth that extends from the canopy top to the active groundwater. At the end of the growing season deeper than upper soil water was used for plant water uptake.
Geochemical focusing and burial of sedimentary iron, manganese, and phosphorus during lake eutrophication
From the distribution of manganese, iron and phosphorus within sediment cores from 11 water depths of Lake Arendsee, changes in the trophic state and oxygen conditions could be reconstructed. The redox-controlled geochemical focussing induced authigenic vivianite formation under oligo-mesotrophic conditions about 100 years ago, resulting locally in strongly increased burial phosphorus deposition.
Spatial variability of radon production rates in an alluvial aquifer affects travel time estimates of groundwater originating from a losing stream
Radon in surface water is mostly used to localise and quantify groundwater discharge. The study presents the opposite approach and use radon to estimate travel times of infiltrated surface water in the aquifer. The spatial heterogeneity of radon production rates complicates this approach, but the problems can be overcome by additionally considering temperature and hydraulic heads.
Estimates of water partitioning in complex urban landscapes with isotope-aided ecohydrological modelling
The authors used isotopes in an ecohydrological model to estimate evapotranspiration (ET) from the landscape of Berlin. This resolved components of ET and quantified transpiration, soil evaporation and evaporation of vegetation-intercepted water. Transpiration from tree-covered areas dominates; with ~80% of ET for urban cooling coming from woodland green spaces covering ~25% of the urban area.
Wood ash as an additive in biomass pyrolysis: effects on biochar yield, properties, and agricultural performance
Functional multi-scale integration of agricultural nitrogen-budgets into catchment water quality modeling
Using field-experimental data, crop N uptake responses to fertilizer management were parsimoniously conceptualized and integrated into a catchment diffuse-N model. The improved catchment modeling further facilitated integration with agricultural budget-based assessments.
Visualizing catchment-scale spatio-temporal dynamics of storage-flux-age interactions using a tracer-aided ecohydrological model
The authors used a tracer-aided ecohydrological model to quantify changes in water flux, storage, and age to improve understanding of spatial differences in catchment response through wet and dry cycles. The visualization tool revealed interannual changes in catchment-scale vegetation water usage and water ages and independent effects on individual species and responses / resilience to droughts.
Divergent roles of iron and aluminum in sediment organic matter association at the terrestrial–aquatic interface
The authors hypothesized that the variation in sediment redox and pH regime govern how iron (Fe) a.aluminum (Al) interact with organic matter (OM) in near-surface mineral sediments.The reactive monomeric Al preferably binds with organic ligands from less-decomposed OM under acidic and anoxic conditions. Low-crystallinity Fe formed under oxic conditions binds with more microbially-processed OM.
Seasonal differences in the attenuation of polar trace organics in the hyporheic zone of an urban stream
The authors investigated the attenuation of trace organic compounds (TrOCs) at a river influenced by treated wastewater during a sampling campaign in summer and one in winter. Contrary to their expectations, they found higher attenuation for 12 out of 18 TrOCs in winter, while three TrOCs were better attenuated in summer. Sediment conditions varied between seasons.