A5084134522- Hydrology and Watershed Management Studies
- Plant Water Relations and Carbon Dynamics
- Tree-ring climate responses
- Groundwater and Isotope Geochemistry
- Cryospheric studies and observations
- Hydrology and Sediment Transport Processes
- Soil and Unsaturated Flow
- Soil Moisture and Remote Sensing
- Flood Risk Assessment and Management
- Soil and Water Nutrient Dynamics
- Karst Systems and Hydrogeology
- Isotope Analysis in Ecology
- Soil erosion and sediment transport
- Groundwater flow and contamination studies
- Rice Cultivation and Yield Improvement
- Irrigation Practices and Water Management
- Groundwater and Watershed Analysis
- Oceanographic and Atmospheric Processes
- Meteorological Phenomena and Simulations
- Landslides and related hazards
- Climate variability and models
- Geology and Paleoclimatology Research
- Forest ecology and management
- Climate change and permafrost
- Bioenergy crop production and management
University of Göttingen
2023-2025
University of Freiburg
2014-2024
Norsk Hydro (Norway)
2021-2023
Norsk Hydro (Germany)
2023
Summary We assessed how the seasonal variability of precipitation δ 2 H and 18 O is propagated into soil xylem waters temperate trees, applied a hydrological model to estimate residence time distribution in soil, identified temporal origin water taken up by Picea abies Fagus sylvatica over 4 yr. Residence times varied between few days several months increased with depth. On average, 50% consumed trees throughout year had precipitated during growing season, while 40% preceding winter or even...
The intensity and frequency of droughts events are projected to increase in future with expected adverse effects for forests. Thus, information on the dynamics tree water uptake from different soil layers during after drought is crucial. We applied an situ isotopologue monitoring system determine oxygen isotope composition xylem European beech a 2-h resolution together measurements content, transpiration deficit. Using Bayesian mixing model, we inferred relative absolute contribution four...
One of the most important functions catchments is storage water. Catchment buffers meteorological extremes and interannual streamflow variability, controls partitioning between evaporation runoff, influences transit times Hydrogeological data to estimate are usually scarce seldom available for a larger set catchments. This study focused on in prealpine alpine catchments, using 21 Swiss comprising different elevation ranges. comparisons depend definitions. defines types including definitions...
Abstract Water travel times reflect hydrological processes, yet we know little about how in the unsaturated zone vary with time. Using soil physical model HYDRUS‐1D, derived time variable distributions for 35 study sites within Attert catchment Luxembourg. While all experience similar climatic forcing, they differ regard to types (16 Cambisols, 12 Arenosols, and 7 Stagnosols) vegetation cover (29 forest 6 grassland). We estimated site specific water flow transport parameters by fitting...
Abstract. The young water fraction Fyw, defined as the proportion of catchment outflow younger than approximately 2–3 months, can be estimated directly from amplitudes seasonal cycles stable isotopes in precipitation and streamflow. Thus, Fyw may a useful metric inter-comparison studies that investigate landscape hydro-climatic controls on streamflow generation. Here, we explore how varies with characteristics climatic forcing, using an extensive isotope data set 22 small- to medium-sized...
Abstract. The transit time of water is a fundamental property catchments, revealing information about the flow pathways, source and storage in single integrated measure. While several studies have investigated relationship between catchment topography times, few expanded analysis to wide range properties assessed influence selected transfer function (TF) model. We used stable isotopes from mostly baseflow samples with lumped convolution models time-invariant TFs estimate distributions 24...
Karst aquifers provide drinking water for 10% of the world's population, support agriculture, groundwater-dependent activities, and ecosystems. These are characterised by complex groundwater-flow systems, hence, they extremely vulnerable protecting them requires an in-depth understanding systems. Poor data accessibility has limited advances in karst research realistic representation processes large-scale hydrological studies. In this study, we present World Spring hydrograph (WoKaS)...
Abstract. We developed a setup for fully automated, high-frequency in situ monitoring system of the stable water isotope deuterium and 18O soil tree xylem. The was tested 12 weeks within an isotopic labeling experiment during large artificial sprinkling including three mature European beech (Fagus sylvatica) trees. Our allowed one measurement every 12–20 min, enabling us to obtain about seven measurements per day each our 15 probes While induced abrupt step pulse signature, it took 7 10 d...
Abstract. Tree water uptake processes and ecohydrological travel times have gained more attention in recent studies. In situ measurement techniques for stable isotopes offer great potential to investigate these but not been applied much tree xylem soils so far. Here, we used probes isotope measurements monitor the isotopic signatures of soil before after two deuterium-labeled irrigation experiments. To show method, tested our approach with 20-year-old trees three different species (Pinus...
ABSTRACT Water potential is a crucial parameter for assessing tree water status and hydraulic strategies. However, methods measuring potential, such as the Scholander pressure chamber, are destructive, discontinuous difficult to perform in tall forests. Consequently, important dynamics potentials, particularly during short‐term drought, capture. Recent advancements have introduced low‐maintenance sensors capable of continuous, high‐resolution stem potentials. We evaluated these temperate,...
Abstract. To investigate water movement in environmental systems, stable isotope (2H and 18O) ratios of are commonly used tracers. Analyzing the isotopic or adsorbed to substances like soil plant tissue necessitates extraction equilibration prior analysis. One such method, direct vapor equilibration, is popular due its cost-effectiveness straightforward sample processing. However, analysis requires significant manual labor, thereby limiting number samples that can be analyzed. This...
Understanding forest water cycles and the processes influencing them is critical for predicting how environmental changes may impact hydrology. Soil-Vegetation-Atmosphere Transfer (SVAT) models are essential tools simulating understanding fluxes within ecosystems. However, accuracy reliability of these often limited by quality availability input data, particularly soil hydraulic parameters. Consequently, assumptions made in modeling process can lead to underestimations or overestimations key...
Transpiration flux estimations for individual trees usually rely on point-information obtained from a limited number of sap flow sensors and wood core samples. The underlying assumption is that densities properties are sufficiently homogeneous within one tree well represented by few sensor measurements If this justified or not, however, has rarely been experimentally tested quantitatively evaluated. Our objective was to quantify the variability answer question how observed uncertainty could...
Declining foliar phosphorus (P) levels call increasing attention to the cycling of this element in temperate forests. We explored fluxes P a mixed deciduous forest ecosystem six distinct hydrological compartments: Bulk precipitation and throughfall, soil water draining laterally from three different depths (0-15, 15-150, 150-320 cm below surface), groundwater, creek spring discharge, which were sampled at daily bi-weekly resolution March 2015 February 2016. Atmospheric into equally...
Abstract. A vast majority of studies investigating the source depths in soil root water uptake with help stable isotopes implicitly assumes that isotopic signatures and xylem are identical. In this study we show basic assumption is not necessarily valid, since transport between tips an observed point above zone instantaneous. However, to our knowledge no has yet tried explicitly assess distribution velocities within xylem. With a dye tracer experiment could visualize how through happens at...
Abstract Beneficial and negative effects of species interactions can strongly influence water fluxes in forest ecosystems. However, little is known about how trees dynamically adjust their use when growing with interspecific neighbours. Therefore, we investigated the interaction between Fagus sylvatica (European beech) Picea abies (Norway spruce) on water-use strategies aboveground structural characteristics. We used continuous situ isotope spectroscopy xylem soil to investigate source...
Abstract. We developed a setup for fully automated, high frequency in-situ monitoring system of the stable water isotopes Deuterium and 18O in soil tree xylem. The was tested 12 weeks within an isotopic labelling experiment during large artificial sprinkling including three mature European beech (Fagus sylvatica) trees. Our allowed one measurement every 12–20 minutes, enabling us to obtain about seven measurements per day each our 15 probes While induced abrupt step pulse signature, it took...
Abstract Two major global challenges related to agriculture are climate change and the unbalanced nitrogen cycle. For both, national international reduction targets have been defined catalyse policy support for more sustainable farming systems. Miscanthus cultivation in water protection areas has proposed as a contribution achieving these targets. However, thorough understanding of underlying system dynamics at various spatial levels is required before recommendations development can be...
Abstract. The vast majority of studies investigating the source depths in soil root water uptake with help stable isotopes implicitly assumes that isotopic signatures and xylem are identical. In this study we show basic assumption is not necessarily valid, since transport within a plant's instantaneous. However, to our knowledge, no has yet tried explicitly assess distribution velocities xylem. With dye tracer experiment, were able visualize how through happens at wide range which...
Abstract. The transit time distribution of a catchment is linked to the water storage potential and affects susceptibility pollution. However, this characteristic still problematic determine within predict among catchments based on physiographic or geological properties. In study, lumped response convolution models coupled with distributed physically snow model were applied simulate stable isotope compositions in stream discharge measured fortnightly 24 meso-scale Switzerland. Three...
We determined the streamflow transit time and subsurface water storage volume in glacierized high-elevation catchment of Rofenache (Oetztal Alps, Austria) with lumped parameter model TRANSEP. Therefore we enhanced surface energy-balance ESCIMO to simulate ice melt, snowmelt rain input associated δ18O values for 100 m elevation bands. then optimized TRANSEP a four-year period data from modified version at daily resolution. The median best runs revealed mean 9.5 years mobile 13,846 mm....
Abstract. Recent advances in situ measurement techniques for stable water isotopes offer new opportunities to improve the understanding of tree uptake processes and ecohydrological travel times. In our semi–controlled experiment with 20–year–old trees three different species (Pinus pinea, Alnus incana Quercus suber) placed large pots, we applied probes isotope measurements monitor isotopic signatures soil xylem before after two deuterium labelled irrigations. Additional destructive sampling...
Abstract. Flood marks are rarely utilized in hazard assessment, mainly because of a lack data availability and accessibility mistrust their reliability. Challenging these common assumptions, we present an approach for evaluation practical utilization flood by the example Kinzig River, Rhine tributary from Black Forest with history severe floods. We combined written documents describing field mapping at three study sites collected information relating to 89 – about 50 % them still preserved...
<p>In the face of global climate change, a well-informed knowledge plant physiologic key parameters is essential to predict behavior ecosystems in changing environment. Many these may be determined with lab or pot experiments, but it could prove problematic transfer results obtained such experiments small trees fully grown trees. Therefore, new approaches determine relevant for mature are still required. Regarding water uptake, related fine root distribution (maximum depth,...