# Effects of Climate Change on Groundwater Budget, Water Quality and the Local Water Supply in crystalline headwater areas in south-eastern Germany

B. Kopp¹, S. Wendel¹, J. Neumann¹

¹Bavarian Environmental Agency, Groundwater Monitoring, Hof, Germany

The main groundwater reservoirs in the crystalline complexes of the Moldanubikum (Bavarian Forest) and the Saxothuringikum (Fichtelgebirge) are concentrated within the weathering zone, with numerous springs forming the headwater regions of the adjacent river systems. Local water suppliers depend, to a high degree, on water originating from these spring systems draining the predominantly shallow aquifers. In context of climate change, the local water resources as well as the water quality are therefore vulnerable to the projection of a drier and warmer climate in the future. This makes it necessary to customize the public water supply structure to periods of water shortages, especially during summer when water demands are highest.

To increase our knowledge about the effects of climate change on the water budget, case studies in the Ilz catchment, situated in the Bavarian Forest, as well as in the headwater areas of the Saale, Eger and Oberer Main River in the Fichtelgebirge in the north-east Bavarian crystalline (NOBYK) were conducted to investigate the present and future yield of groundwater. These areas can be considered to be representative for a variety of similar crystalline low mountain ranges in Germany and Europe. To this end, water balance models (ArcEGMO-PSCN, Ilz catchment and WaSiM-ETH, NOBYK) were applied in high resolution to quantify the mean and inner-annual effects of climate change (WETTREG 2006 and 2010 scenarios, based on ECHAM5-OM1 A1B) on river and spring discharge in the near (2021 - 2050) and distant future (2051 - 2100). The meteorological input parameters for the model regions, based on weather stations from the DWD (German Meteorological Service), were regionalized and validated with the time period from 1980 - 2008 for the Ilz catchment and from 1971 - 2000 for the NOBYK. The water balance models were calibrated at 13 river gauges, snow cover gauges as well as measured soil temperature and -moisture in the Ilz catchment and at 29 river and spring gauges in the NOBYK area. Similar to their geology, elevation and land cover, the two study areas exhibit an analog hydrological response to the climate scenarios: In winter, higher mean temperatures and an increase in precipitation result in increasing evapotranspiration (ET) rates alongside an earlier occurrence of the yearly river runoff peaks due to a change in snowmelt dynamics. In summer, a decrease in precipitation leads to a partly significant decrease in ET, which can be explained by the lack of total available water during drought periods. Groundwater recharge is therefore limited or even negative during summer. As a consequence, total river discharge is going to decline during spring, summer and autumn for both scenarios with extending low flow periods. Generally, the simulated spring discharge pattern shows no clear inner-annual trend in the near and distant future.

Additionally, a water quality case study in the Lehstenbach catchment, within the NOBYK area, was realized in cooperation with the University of Bayreuth, Department of Soil Ecology and the Department of Hydrology. The chosen catchment represents typical forested mountain ranges with fens in saturated areas around open water bodies. Here, the focus was on the trend and the dynamics of the dissolved organic carbon (DOC) and Nitrate export. In many forested regions in Europe and northern America, increasing DOC and Nitrate concentrations have been observed over the last decades. Both compounds have the capability to deteriorate the drinking water. To get insight into the DOC and Nitrate export dynamics, a high resolution measurement period was conducted: Following precipitation events, DOC in fen areas is quickly mobilized by fast runoff components after the groundwater level increased to surface near levels. As the DOC production is closely linked to temperature, DOC concentrations peaked during summer. However, the highest total DOC export takes place during winter when discharge is highest. The dynamic in Nitrate export behaves conversely; low concentrations were measured during summer runoff peaks, while higher concentrations were measured during winter, indicating slow runoff pathways in deeper groundwater. The simulated future increase in discharge during winter is accompanied by an increase in total DOC export, while the overall summer export remains stable despite a decrease in summer discharge due to frequent heavy rainfall events resulting in increased DOC export rates.
Quantification of denitrification via N₂ balances provides unique insights to the in-stream nitrate cycle

V. Kunz¹

¹UFZ, ASAM, Magdeburg, Germany

Nitrate can be removed from aquatic (lotic) systems in various ways eg. assimilatory uptake, adsorption or intermediate storage in sediment and wetland. Amongst these, denitrification, the microbial reduction of NO₃ to N₂ (g), is the only process which eternally eliminates Nitrate from the system. Unfortunately, due to methodological limitations, the quantification of in-stream denitrification is so far hardly assessed.

Long time monitoring in form of mass balances in the Lower Bode indicates that nitrate is processed in the run of this river. Our objective is to disentangle the different processes leading to this reduction. It is of particular interest to quantify the proportion of removed nitrate attributed to denitrification. In order to do so, we measured in situ dissolved N₂ (the end product of microbial nitrate reduction) in a Lagrangian approach. Due to the poor reactivity and high background of nitrogen in water and atmosphere, commonly used methods (GC, head- space MS) fail to deliver usable data. Sufficiently accurate results can up-to-date exclusively be achieved measuring N₂/Ar concentrations on a membrane inlet mass spectrometer. An assessment based on a complex set-up and the determination of various side parameters.

Here we demonstrate how this approach especially in combination with the investigation of solute exchange to the interstices, provides unique insights in the in-stream nitrate cycle.
# Modeling Carbon Dynamics for Small Ponds in the North-East of Germany

M. Omari<fnref n="1" />, G. Lischeid<fnref n="1" />, G. Arhonditsis<fnref n="2" />

Due to the complexity and the large number of the biogeochemical processes in small ponds and their adjacent arable areas, any modeling of carbon dynamics in kettle holes should take into account interactions between multiple elements, e.g. carbon, nitrogen, phosphorus, oxygen and other chemical elements. A significant fraction of these elements originate from agricultural areas and are transported to the ponds via wind or water erosion. This input is processed by phytoplankton, macrophytes, bacteria and fungi which are the key players for biomass production and decomposition. For this, a complex eutrophication model was developed for the Rittgarten kettle hole which is surrounded by arable fields located in eastern part of Germany to get an insight into the substantial short-term variations of these processes, assessing carbon budget and to best understand their effects on water quality as well. The model combines phytoplankton as a single group and describes its interaction with duckweed and submerged macrophytes. We also considered the incorporation of the nutrients, organic and inorganic matters in the overlying water as well as in the sediment bed. In addition, the model takes into consideration the phosphate-iron and dissolved inorganic carbon-calcium interactions. Model calibration is performed using data derived from time series of water quality and monitoring data of the LandScales project.

<footnote n="1">¹Leibniz Centre for Agricultural Landscape Research, Institute of Landscape Hydrology, Müncheberg, Germany</footnote>

<footnote n="2">²University of Toronto, Department of Physical & Environmental Sciences, Toronto, Canada</footnote>
# High Resolution Monitoring of Hydrogeochemical Gradients Across the Dynamic Soil-Groundwater Interface in a Riparian Landscape

N. Gassen<fnref n="1" />, A. Musolff<fnref n="2" />, C. Griebler<fnref n="1" />, C. Stumpp<fnref n="1" />

Riparian zones are important buffer zones for non-point groundwater contaminants like nitrate. Shallow water tables favour denitrification, as nitrate rich groundwater comes into contact with anoxic, organic rich layers in hydric soils. To date, riparian research has focused on influences of groundwater-surface water interactions on nitrate removal mechanisms, but little is known about processes occurring at the interface between the saturated and the unsaturated zone during groundwater table fluctuations. Strong groundwater level fluctuations are a typical feature of riparian zones, caused by the tight response to surface water-level fluctuations and influences of rainfall forcing and evapotranspiration. Therefore, the objective of this study is to identify hydrogeochemical gradients across the soil-groundwater interface and monitor their response to groundwater table changes. High-resolution multi-level monitoring wells will be installed in the riparian corridor of the Selke TERENO field site in the Harz Mountains with sampling ports both in the unsaturated and the saturated zone. We expect that dynamic conditions in the vicinity of the groundwater table play an important role for matter turnover processes as increased dispersivities enhance solute transport and thus increase potential mixing of rate limiting reactants. By resolving processes at the intended small scale, hot spots and hot moments of biogeochemical turnover processes can be identified and their relevance for overall degradation processes can be estimated. This leads to a better prediction and improved management strategies for buffer mechanisms in riparian zones.

<footnote n="1">¹Helmholtz Zentrum München - German Research Centre for Environmental Health, Institute of
Groundwater Ecology, Neuherberg, Germany</footnote>

<footnote n="2">²Helmholtz-Centre for Environmental Research, Department of Hydrogeology, Leipzig, Germany</footnote>
# Spatial and temporal links between DOC and NO₃⁻ in a forested mountainous headwater catchment in the Eifel, Germany

S. Weigand<fnref n="1" />,<fnref n="2" />, R. Bol<fnref n="1" />, B. Reichert<fnref n="2" />, F. Bydalek<fnref n="1" />, A. Graf<fnref n="1" />, A. Lücke<fnref n="1" />, W. Tappe<fnref n="1" />, W. Amelung<fnref n="1" />,<fnref n="3" />, H. Vereecken<fnref n="1" />

The spatial and temporal variability of the concentration of dissolved organic carbon (DOC) and nitrate (NO₃⁻) was studied by means of weekly grab samples over a 4-year period (2009-2013) in a forested headwater catchment (Wüstebach, Germany).

Stream water DOC values varied between 0.8 and 7.4 mg/l, with a mean value of 2.7 mg/l. NO₃⁻ concentrations ranged between 2.8 and 12.2 mg/l, with a mean value of 5.7 mg/l. The stream water DOC values were negatively correlated to NO₃⁻ concentrations (highest R<fnref n="2" />=0.54). Hence, low DOC and high NO₃⁻ concentrations were measured during summer in stream waters. Generally, surficial water exhibited high DOC, low NO₃⁻ concentrations and high variability while ground waters were characterised by low DOC, high NO₃⁻ values and low variability. The data confirmed observations by others, which suggest the existence of a negative nonlinear relationship between NO₃⁻ and DOC occurring along a hydrologic continuum from soils over to streams and lakes. However, we also wanted to test the hypothesis whether or not this correlation between DOC and NO₃⁻ depends on the time-point of observation. Cross wavelet analysis were performed and time lags quantified on stream and groundwater monitoring data. The wavelet analyses revealed negative cross correlations with a three month shift of NO₃⁻ compared to DOC. The strongest correlations occurred at the range of 6-7 months, especially for the surface water (up to an R<fnref n="2" /> close to 1). The study did therefore confirm a direct correlation between DOC and NO₃⁻ in surface waters, but only when short term random effects are neglected.

Within the whole catchment, general spatial differences in annual trends in DOC and NO₃⁻ concentrations in tributaries and various superficial components were found. This most likely reflects the localized differences (soil, hydrological and bedrock conditions) in the relative contributions of surface and ground water to the stream water, probably in response to prevailing weather conditions.

<footnote n="1">¹Forschungszentrum Jülich, IBG-3, Jülich, Germany</footnote>

<footnote n="2">²Universität Bonn, Steinmann Institut, Bonn, Germany</footnote>

<footnote n="3">³Universität Bonn, Institute of Crop Sciences and Resource Conservation, Bonn, Germany</footnote>
Assessing the imbalance between sediment rating curve options and spatial scales -
reducing uncertainties in water quality modeling

Y. A. Bossa<fnref n="1" />, B. Diekkrüger<fnref n="2" />

Suspended sediment generated at catchment outlet using sediment rating curves strongly depends amongst other factors on: (i) rainfall event intensity and amount; (ii) land surface state in terms of physical surface characteristics, seasonal vegetation stages, land use/management; and (iii) catchment sizes, on which depend the increase or decrease in the complexity of land surface states, the measurement strategy so the sediment rating curve options. This study aims to clarify the suitability of the classical Sediment-Discharge Rating Curves (SDRC) compared to Sediment-Turbidity Rating Curves (STRC) for a given catchment size to provide reliable time-series data for water quality and soil degradation modeling. Thus, SDRC and STRC were computed and compared over two consecutive years 2004-2005 at three different catchment scales of 16.5 km<fnref n="2" />, 586 km<fnref n="2" /> and 2,324 km<fnref n="2" /> in the upper Ouémé catchment in Benin. For that, sub-hourly turbidity measurements were considered together with sub-daily suspended sediment concentration and water discharge data. The SDRC were fitted using a Generalized Reduced Gradient Nonlinear approach. The results suggested that the SDRC approach behaves poorly but improves with increase catchment size. In opposite to that, the STRC approach provides acceptable results at all scales. This can be explained by complex behavior at the small scale due to landscape and rainfall patterns. With increasing size of the catchments, variability smoothes out caused by mixing processes as well as erosion and sedimentation within the river system. Therefore, the SDRC approach is only suitable for large catchments but does not allow analyzing the rainfall-erosion patterns.

**Keywords:** Sediment; turbidity; water discharge; rating curve; spatial scale; land surface state.

<footnote n="1">¹West African Science Service Center on Climate Change and Adapted Land Use – WASCAL,
Ouagadougou, Burkina Faso</footnote>

<footnote n="2">²University of Bonn, Department of Geography, Bonn, Germany</footnote>
# Effects of temporal and spatial resolution of calibration data on integrated hydrologic water quality model identification

S. Jiang¹, S. Jomaa², O. Büttner ², M. Rode²

¹NIGLAS, Nanjing, China

²UFZ, Magdeburg, Germany

Hydrological water quality modeling is increasingly used for investigating runoff and nutrient transport processes as well as watershed management but it is mostly unclear how data availability determines model identification. The objective of this study is to investigate the impacts of temporal and spatial resolution of calibration data (discharge and nitrate-N concentrations) on integrated hydrologic water quality modeling performance, parameter identification and predictive uncertainty. The HYPE (Hydrological Predictions for the Environment) model, which is a process-based, semi-distributed hydrological water quality model, was applied in a nested meso scale catchment Selke (463 km²) located in central Germany to simulate discharge and inorganic nitrogen (IN) transport. The Bayesian inference based approach DREAM<sub>(ZS)</sub> was combined with the HYPE model to conduct parameter calibration and uncertainty analysis. Split-sample test was used for model calibration (1994-1999) and validation (1999-2004). Both dynamics and balances of water and IN load were well captured with NSE greater than 0.83 during validation period. IN concentration and daily IN load were found to be highly correlated with discharge, indicating that IN leaching is mainly controlled by runoff. Multi-site calibration was able to improve model performance at internal sites, decrease parameters' posterior ranges and prediction uncertainty. The impacts of multi-site calibration on parameter optimization and prediction accuracy depend on the variability of catchment characteristics. Nitrogen-process parameters calibrated using continuous daily averages of nitrate-N concentration observations produced better and more robust simulations of IN concentration and load, lower posterior parameters' ranges and IN concentration prediction uncertainty compared to the calibration against non-continuous biweekly nitrate-N concentration measurements. This study helps us to understand the realism of model structure and design reasonable hydrological water quality sampling campaigns.
CHARACTERIZATION OF STREAM-AQUIFER INTERACTIONS IN CARBONATE ROCKS

P. Briers<fnref n="1" />, C. Sohier<fnref n="2" />, F. Schmit<fnref n="3" />, V. Hallet<fnref n="3" />, J.-P. Descy<fnref n="4" />, P. Orban<fnref n="1" />, A. Degré<fnref n="2" />, S. Brouyère<fnref n="1" />

Groundwater - surface water interactions play a fundamental role in terms of quantity and quality of water and in terms of ecological quality of rivers. Moreover, the hyporheic zone influences the mobilization and degradation of many pollutants. Despite many research efforts and the necessity to better understand such interactions in order to reach effective management of water resources, stream-aquifer exchanges remain poorly understood, in particular in fractured carbonate environments.

In this context, the overall objective of the project is to identify, characterize and quantify groundwater - surface water interactions in carbonate rocks, to assess the impact of these interactions on the ecology of the stream and to better understand the nitrate pathway from surface to the river (soil - vadose zone - groundwater - hyporheic zone - river). Carbonate systems present a high variability of fluxes because of groundwater flow inside fractures and karstic networks. This leads to transport and dispersion of pollutants and to localized groundwater inflows in the river with high variations in time. The heterogeneities and the impact of flows are difficult to emphasize in such systems. Therefore, the monitoring setup has to be adapted to be able to catch the dynamic of these environments. This implies the need for increasing the number of spatial and temporal measurements.

In order to accomplish this objective, two main observation scales are considered. First, a portion of a stream is studied in quantitative and qualitative ways via a dense instrumentation and monitoring. Electrical resistivity tomography (ERT) identifies fractures and characterizes their geometry by contrast of resistivity. Streaming potential (SP) locates groundwater fluxes in the banks via an electrical signal induced by the polarization of the water. These measurements allow locating groundwater inflows in the stream that are then characterized for the temporal approach by a distributed temperature sensing (DTS). This technique measures shifts of temperatures (0.1°C by 1m) resulting from the mix of groundwater (constant temperature: 12-13°C) and surface water (16-17°C during summer, 4-5°C during winter). Incoming groundwater fluxes, previously located by geophysics, modify surface temperature and are recorded by DTS. Repetitions of DTS measurements allow characterizing temporal variations of groundwater incomes.

Furthermore, nitrate pathway is studied on an experimental site where different depths piezometers are drilled. Tracer and infiltration tests are performed to assess mechanism and time of transfer in the unsaturated and saturated zone.

Second, a global analysis is foreseen. The selected watersheds are mainly covered by agricultural activities with some influence from inhabited areas. Detailed enquiries regarding the agricultural practices are performed. Soil samples are taken on hundreds of parcels to quantify the nitrate content on the 0-90 cm depth. The agricultural practices as well as the hydrological behavior of the catchments will be modelled in order to assess water flows and nitrogen transfer to surface water and groundwater using the EPICgrid model.

The impact of the hyporheic zone on the degradation of nitrate is studied by different techniques such as hydrochemical analyses in groundwater and in the stream and by conservative and non-conservative tracer tests. In-stream nitrate concentration, along with other parameter, is monitored at high temporal resolution by multiparameters probes. Moreover, key aquatic communities are studied in detail, in order to identify indicators of the groundwater - surface water interactions that may have significant impacts, possibly leading to alteration of the ecological status of the surface waters.

<footnote n="1">¹University of Liège, Hydrogeology and Environmental Geology, Liege, Belgium</footnote>

<footnote n="2">²University of Liege, Water and Soils Systems, Gembloux, Belgium</footnote>

<footnote n="3">³University of Namur, Geology, Namur, Belgium</footnote>

<footnote n="4">⁴University of Namur, Freshwater Ecology, Namur, Belgium</footnote>
It is expected that the results from the combined experimental setup will provide an improved characterization of the variability of stream-aquifer interactions in carbonate rocks and a better understanding of the nitrate dynamics.
# Application of isotopic tracers and hydrochemical data for the investigation of groundwater flow in a young moraine area

H. Wilke¹, C. Tecklenburg¹, A. Güntner¹, T. Blume¹

¹GFZ, Potsdam, Germany

Decreasing groundwater and lake levels over the last 30 years have been observed at many locations in northeastern Germany. However, the precise reasons for this decline are still unclear. Our investigation aims at a better understanding of the hydrodynamic behavior of a shallow aquifer using isotopic tracers and hydrochemical data. Focus area is the domain of Lake Hinnensee, which is located in a young moraine area in Mecklenburg-Vorpommern. The research area consists of the Pommeranian main terminal moraine in the north and the outwash plain in the south. The unconfined aquifer in the Lake Hinnensee area is mainly composed of glacial medium sands.

Little knowledge about groundwater flow directions and dynamics is available for the Lake Hinnensee region. However, as we are looking at a purely groundwater controlled lake system (no surface inflows or outflows), this information is essential for a better understanding of the ongoing processes controlling both lake and groundwater levels.

First field campaigns were carried out in 2012. The establishment of seventeen observation wells and a groundwater level monitoring system, electric resistivity tomography measurements as well as the investigation of subsurface characteristics such as hydraulic conductivity supplied important first insights into the structures and properties of the hydrogeological system.

From recharge to discharge, groundwater is subject to different chemical reactions and physical changes. Information on water chemistry is used to analyze groundwater residence times, flow paths and origin. The stable isotopes oxygen-18 and deuterium and the radioactive radon are used as tracer. In addition, the ion content and the physico-chemical parameters temperature, electrical conductivity, pH, oxygen content and redox potential are measured. For this purpose the observation wells were pumped every six weeks between May 2013 and November 2013 and every eight weeks from November 2013 to May 2014. From analyses of isotope and radon contents as well as of physico-chemical parameters spatial patterns of different groundwater regions can be determined. The regions may indicate areas of different groundwater origin, flow paths and residence times, which amongst others are determined by subsurface properties, structures and boundaries. The highest water levels are monitored in April and May, the lowest in October and November. In general the hydrographs of the seventeen observation wells are relatively similar in their seasonal dynamics. However, they show slightly different trends, possibly pointing at different groundwater origins or flow paths. First results of the isotope and radon measurements as well as an overview of the ion content, the spatio-temporal distribution of the physico-chemical parameters and the water level developments in the area are presented.
Evaluation of trends in nutrient concentrations

F. van der Bolt<fnref n="1" />

Water quality measurement analysis and modeling are combined to monitor and evaluate the nutrient concentrations in catchments. The developed method resulted in more and better information than achieved from the measurements before. The results have been used to contribute to the evaluation of the Dutch fertilizer policy. With the knowledge gained it is possible to improve the use of the measurements as well as to optimize the design of the measuring networks.

<footnote n="1">¹Wageningen UR, Environmental Sciences Group, Water and catchment management, Wageningen, Netherlands</footnote>
Physically-based modeling in an experimental alpine catchment

G. Bertoldi<fnref n="1" />, S. Della Chiesa <fnref n="1" />,<fnref n="2" />, M. Engel <fnref n="1" />,<fnref n="3" />, G. Niedrist <fnref n="1" />,<fnref n="2" />, C. Notarnicola <fnref n="4" />, U. Tappeiner<fnref n="1" />

Mountain regions are particularly sensitive to climate change and at the same time they represent a key water resource not only locally but as well for lowland areas. Therefore, there is a strong need to improve the capability of hydrological models to quantify changes of the water cycle components, considering interactions and feedbacks with climate and vegetation. Process-based hydrological models represent promising tools for addressing those needs. However, their inherent complexity sometimes limits their applicability for operational purpose, but they offer great potential in terms of tools to test hypotheses, which can be verified in the field.

GEOtop is a hydrological model that calculates the energy and mass exchanges between soil, vegetation, and atmosphere, accounting for land cover, water redistribution, snow processes, glacier mass budget and the effects of complex terrain and thus is one of the few models that was built with this complexity in mind. Recently, it has also been coupled with a dynamic vegetation model in order to simulate alpine grassland ecosystems.

In this contribution, we want to present an application of the GEOtop model in simulating above ground biomass (Bag) production, evapotranspiration (ET), soil moisture (SM) and snow water equivalent (SWE) for the emerging LTER area of Matsch/Mazia, located in the Venosta/Vinschgau valley in the European Alps. In this area an intensive hydrological and ecological monitoring activity with ground observations and remote-sensing products has been established in the last five years.

Simulations results underlines the capability of the model to predict the observed changes on the water budget components along the altitudinal gradient, as well its potential in terms of predicting future changes. However, detailed observations are needed to parameterize the model.

In this contribution we want to highlight the role of the experimental observations for a multi-scale and multi-process evaluation of the model. Plot scale observations of evapotranspiration, soil moisture and snow cover, combined with remote sensing observations help to discriminate between uncertainties in input data and model parameterization. Moreover, we want to show how, when the model is used in combination with detailed experimental campaigns, a more coherent and accurate estimation of the catchment hydrological behavior is possible with respect to the one that is possible with simpler lumped models.

<footnote n="1">¹EURAC, Institute for Alpine Environment, Bolzano, Italy</footnote>

<footnote n="2">²University of Innsbruck, Institute of Ecology, Innsbruck, Italy</footnote>

<footnote n="3">³University of Bozen-Bolzano, Faculty of Science and Technology, Bolzano, Italy</footnote>

<footnote n="4">⁴EURAC, Institute for Applied Remote Sensing, Bolzano, Italy</footnote>
# High resolution analyses of partially varved sediments from Lake Tiefer See (NE Germany) for the last ca. 10,000 years - a multi proxy study

N. Dräger¹, S. Wulf¹, M. Theuerkauf², B. Plessen¹, U. Kienel²,¹, M. Słowiński¹,³, T. Hübener⁴, P. Dulski¹, F. Ott¹, S. Lorenz², A. Brauer¹

¹ GFZ German Research Centre for Geosciences, Potsdam, Germany

²Ernst-Moritz-Arndt University, Greifswald, Germany

³Polish Academy of Sciences, Torun, Poland

⁴University, Rostock, Germany

Annually laminated (varved) lake sediments represent unique archives in continental areas providing both, precise chronologies and seasonally resolving proxy data. Lake Tiefer See in NE Germany provides such an archive for an integrated multi-proxy study based on high-resolution sediment analyses and monitoring of modern deposition processes forming subannual laminae.

Lake Tiefer See is located within the terminal moraine belt of the Weichselian glaciation and is part of the Klocksin Lake Chain which has been formed as a subglacial gully system. Coring campaigns at the deepest part of the lake (62 m depth) yielded 7 sediment profiles, 3 of which reached glacial sand deposits at the base. From these individual profiles a ~10.5 m long continuous composite profile has been compiled by means of identifying macroscopic and microscopic correlation layers. The chronology of the core sequence is based on varve counting, AMS ¹⁴C dating of terrestrial plant remains and identification of cryptotephras including the Laacher See Tephra originated from the Eifel region. The position of the Laacher See Tephra suggests an onset of lake sedimentation in the late Allerød at ca. 13,000 years BP.

A combined approach of sediment microfacies analyses using large-scale thin sections, µ-XRF element scanning of split sediment cores, geochemical analyses of the bulk sediment and pollen analyses for the complete composite profile and diatom analyses for certain intervals has been carried out. First results include a distinct increase of the endogenic calcite contents at ca. 5,000 years BP and the appearance of poorly varved or homogeneous intervals starting ca. 4,000 years BP. Poorly and non-varved intervals are characterised by higher Ti and K count rates indicating increased detrital matter flux into the lake by surface runoff and/-or aeolian transport. Results of pollen data imply increased forest opening and agricultural activity during these intervals with poorly preserved varves.

Possible mechanisms for the abrupt changes beginning at ca. 5,000 years BP include local influences (e.g. lake level fluctuation, anthropogenic disturbances on the vegetation in the lake vicinity) and increasing maritime influences of the North Atlantic related to changes in atmospheric circulation patterns and wind strength.

The data from the Lake Tiefer See sediment record are compared with the varved lake record from Lake Czechowskie, located ca. 400 km to the East in central northern Poland in a similar geomorphologic position, based on independent and high precision chronologies. The aim of this comparison is to test the hypothesis of decreasing North Atlantic maritime influences towards more continental regions in the East.

This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis -ICLEA- of the Helmholtz Association and uses TERENO infrastructure.
# Hydrological and sedimentological processes of flood layer formation in Lake Mondsee

L. Kämpf¹, A. Brauer¹, P. Mueller², A. Güntner², B. Merz²

¹Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, 5.2 Climated Dynamics and Landscape Evolution, Potsdam, Germany

²Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Section 5.2 Hydrology, Potsdam, Germany

Detrital layers in lake sediments are valuable recorders of extreme river floods and are increasingly exploited to establish continuous flood chronologies reaching several millennia back in time. The annually laminated sediments of Lake Mondsee (486 m a.s.l., Upper Austria) contain a seasonally resolved flood layer chronology over the past 7100 years. Despite the great potential especially of varved lake sediments for reconstructing long flood time series, there are still some confinements with respect to their interpretation due to a lack in understanding the complex chain of processes leading to the formation of detrital layers.

For this purpose, a comprehensive monitoring network was set up at Lake Mondsee recording hydrological and suspended sediment dynamics from the catchment to the lake. Precipitation, runoff and suspended sediment concentration are monitored continuously at the outlet of the main tributary to the lake, the Griesler Ache River; water samples were taken automatically during runoff events. Within the lake, sediment is collected continuously in 3- to 12-day intervals by sediment traps, one located close to the river inflow and one in a more distal position where the long sediment record was retrieved.

Our monitoring data cover the period from January 2011 to November 2013 including 26 floods of different amplitude (10 to 110 m3/s) which triggered variable fluxes of catchment sediment to the lake floor (4 to 758 g/(m2*d)). The detailed comparison of runoff and sediment data revealed (i) empiric thresholds for triggering significant sediment influx in the proximal (20 m3/s) and distal lake basin (30 m3/s), (ii) a relation between the amplitude of flood discharge and the amount of sediment flux and (iii) a variable spatial sediment distribution during high magnitude floods. The latter is mainly due to the role of (i) flood duration, (ii) the existence of a thermocline and (iii) local sediment sources which episodically contribute additional detrital material. Monitoring floods of very different intensity and seasonal occurrence shows a complex relation between flood amplitude and sediment signal. This helps to identify uncertainties in the Lake Mondsee flood layer record and demonstrates the potential for a closer link of instrumental and sediment-based flood time-series.
# Colluvial Sediments and Bogs in the Ammer Mts. as GeoArchives: Predicting Soil Stability under Land Use and Climate Change (TUM-CZO)

J. Völkel¹, D. Schwindt¹, J. Winkelbauer¹

¹Technische Universität München, Wissenschaftszentrum Weihenstephan, Freising, Germany

Soils represent the central part of the complex interaction system of the Critical Zone. As such, soil loss causes serious, irreversible loss of vital ecosystem services. Hence, deter- mining risks of soil degradation and soil loss is a major task within the Critical Zone research. As an example for recent research within the Critical Zone Observatory of the Technische Universität München (TUM-CZO), located in the Ammer Mountains of the Bavarian Alps, we present a project which deals with the investi- gation of possible soil loss triggers and dyna- mics in alpine landscapes by reconstructing mineral colluvial deposits in peat bogs.

Within the Ammer catchment, we investigate a total of twelve peat bogs distributed across an altitude gradient from alpine to subalpine and lowland landscapes. Represented are the study sites investigated so far with special focus on the southern alpine part of the catchment. Three sites within the northern prealpine catchment are still to be prospected.

The investigation of colluvial deposits in peat geoarchives provides perfect conditions for the reconstruction and interpretation of past soil erosion events. In particular we intend to: evaluate peat geoarchives with regards to soil morphodynamics (caused by former climate and land use changes) assess frequency and amplitude of disturbances (system stability/lability) give a valuable risk assessment on the threat/loss of ecosystem, define management strategies for forestry, agriculture and conservation validate existing szenarios (proxy data).
# A spatial reconstruction of European droughts from an isotope-climatenetwork approach

G. Helle¹, M. Freund¹, I. Heinrich¹, U. Cubasch², I. Members¹

¹GFZ Deutsches Geoforschungszentrum, Sektion 5.2 Klimaentwicklung and Landschaftsdynamik, Potsdam, Germany

²FU Berlin, Meteorologische Institut, Berlin, Germany

A well-verified spatial reconstruction of European moisture variability back to 1600AD was established from a network of tree-ring stable isotope records (C+O). Principle component regression and change point detection techniques have been applied and revealed strong coherences among the tree ring isotope records, convincing congruence with isotope theory and a powerful climate-proxy relationship with the summer Standardized-Precipitation-Evaporation-Index (SPEI; July-August). The presentation will outline and discuss trends in the spatial extent of drought events, coherences with atmospheric regimes (SNAO) and comparisons with other European climate reconstructions.
# Climate and tree growth in TERENO West & Northeast

K. Fregien<fnref n="1" />, I. Heinrich<fnref n="1" />, G. Helle<fnref n="1" />, B. Neuwirth<fnref n="2" />

The TERENO Coordination Team Geoarchives (http://teodoor.icg.kfa-juelich.de) aims to improve the understanding of the long-term climate-growth relationships since this is the crucial link between soil, vegetation and atmosphere. Tree rings allow for high-resolution and long-term analyses, especially in conjunction with lake sediment records. Since one of the major aims of TERENO West and Northeast is to combine tree rings and lake sediments, it is important to first identify differences and commonalities in the climate-growth relationship in West and Northeast. The insights will sharpen our comprehension concerning the impact of climate change in different TERENO regions spatially and temporally.

Tree-ring width chronologies of oak from two different regions (W= West and NE=Northeast) were developed and correlated with monthly precipitation, temperature and Palmer Drought Severity Index (scPDSI) of the previous and current vegetation period using Pearson's correlation coefficient. Additionally, as a discontinuous approach, an extreme year analysis was conducted in order to concentrate on the climate growth relationships for selected extreme years.

Correlations between tree rings and climate data reveal a stronger common signal in NE than W. Oaks from both regions are correlated significantly with spring and early summer precipitation, whereas less significant temperature signals were found. Tree growth of oak from NE responds stronger to moisture deficits.

In total, 18 years of extreme growth anomalies were detected for the period from 1901 to 1996. More negative than positive extreme years were found in both regions. Only negative extreme years are shared between both regions but no positive extreme years were found at the same time. Tree growth in NE responds stronger to extreme events. Analyses revealed that extreme years of tree growth are also characterised by severe deviations from the long-term (1901-2006) monthly temperature and precipitation means.

Overall, the analyses indicate similar climate-growth relationships in TERENO W and NE, with stronger correlations in NE. The results suggest that more reliable climate reconstructions are likely to be achieved with oak in TERENO NE, probably due to the more continental climate in TERENO NE. On-going investigations comprising studies on quantitative wood anatomy and stable isotopes will increase our know-how of the complex climate-growth relationships and lead to comprehensive reconstructions. Since living oak trees in TERENO NE can grow to several hundred years and in addition a lot of archaeological oak wood is available, a regional moisture-sensitive oak chronology of more than 1000 years will be achieved, thereby opening doors to new multi-proxy reconstructions.

<footnote n="1">¹GFZ Deutsches Geoforschungszentrum, Sektion 5.2 Klimaentwicklung and Landschaftsdynamik, Potsdam, Germany</footnote>

<footnote n="2">²University of Bonn, Department of Geography, Bonn, Germany</footnote>
# Finding proxies for historical groundwater table depth in a flat and sandy landscape: examples from the Campine area, NE Belgium

K. Beerten¹, B. Leterme¹

¹SCK-CEN Belgian Nuclear Research Centre, Institute Environment-Health-Safety, Mol, Belgium

Hydrological modelling is usually applied to predict the state of a specific hydrological variable (channel flow, peak run off, groundwater head) for the present and the future. Model calibration and validation is then based on instrumental measurements of variables in the recent past, usually the last few decades. However, this inherently limits the evaluation of model performance because this timeframe is usually too short to encompass the full variability of the hydrological system and its response to driving forces (climate, land use, human activities). Extending the modelling timeframe to historical periods (several centuries) allows to test model performance for different conditions than today, encompassing a wider range of hydrological variables. However, verification of the model output for historical periods requires the acquisition of palaeohydrological proxies describing the state of a specific variable for a given point in time in the past.

In this presentation, we discuss several proxies for historical groundwater table depth and methods to derive them. The study area is a small interfluve within the Nete catchment, Campine area, NE Belgium. Surface altitude ranges between ~ 23 m TAW (Tweede Algemene Waterpassing; m a.s.l.) in the floodplains and ~ 28 m in the dune areas. At present, the groundwater table is on average 1-2 m below the surface and can be recognized as a subdued replica of the topography. Outside the small floodplains, a so-called drift sand landscape developed during the last few centuries, witnessing the strong human impact on the landscape. Other impacts on the landscape can be seen, like the numerous drains that were constructed during the 19th century to expand the arable land, or the straightening and deepening of small rivers and brooks. With respect to soils, the introduction of plaggen agriculture in the 16th century has led to the development of thick Anthrosols, while enhanced soil erosion in the 17th-18th centuries has led to the transformation of typical Podzols into Arenosols.

Redoximorphic features in OSL-dated soil-sediment profiles suggest that, compared to the current situation, the groundwater table was significantly higher (around 1.5 m) ca. 1650AD and even higher between ca. 1000AD and 1600AD. Furthermore, geomorphological investigations showed that the altitude of blown-out surfaces, dated to ca. 1600AD and regarded as an upper bound for the groundwater table, are closely related to the position of redoximorphic features observed in cross-sections cut into the dunes (Beerten et al., 2014a).

Historical maps point out that part of the interfluvium was occupied by shallow pools, at least around 1780AD and 1850AD. Today such pools are much less numerous and artificially fed by water from the mid 19th century established canal that crosses the interfluvium. Field work and DTM-analysis indicates that the groundwater table must have been 1-2 m higher in order to sustain the existence of such pools.

During the 19th century, the Kleine Nete river was straightened and deepened. This must have led to a significant groundwater table lowering in the floodplain. The evidence for a shallow river is derived from the investigation of a section cut across an 18th century palaeo-channel, while information on the geometry is derived from historical maps (Beerten et al., 2014b).

Finally, historical maps, field work and detailed DTM-analysis suggest that around the end of the 19th century, the higher parts of the interfluvium were (still) experiencing high groundwater table conditions as ditches were cut to sustain the newly established pine plantations in the area. An imaginary profile line connecting the bottom of the ditches mimics the position of a groundwater table.

Despite the fact that the nature of the investigated archives is highly discontinuous, and their examination yields temporally and spatially discontinuous information on groundwater table depth in
this specific sandy landscape, it seems that a period of high groundwater table can be identified that
started probably already before 1600AD and lasted until around 1900AD. Land use and vegetation
changes are held responsible for the groundwater table lowering, although the role of climate change
and increasing water demands should be considered as well.

References

Beerten, K., Vandersmissen, N., Deforce, K., Vandenberghe, N., 2014a.Late Quaternary (15 ka to present) development of a sandy landscape in the Mol area, Campine region, north-east Belgium. Journal of Quaternary Science. DOI: 10.1002/jqs.2713.

Beerten, K., Van Nieuland, J., Vandenberghe, D., Deforce, K., Rogiers, B., 2014b. Fluvial development of the Nete valley during the Late Weichselian and (early) Holocene: new data from a cross-section south of Kasterlee (NE-Belgium).Geophysical Research Abstracts 16, EGU2014-5301.
# Challenging a process-based agro-ecosystem model with the impact of erosion on short-term carbon dynamics within an undulating landscape

C. Nendel¹, X. Specka², U. Hagemann², M. Pohl², J. Augustin², M. Sommer³, K. van Oost⁴

¹Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Systems Analysis, Müncheberg, Germany

²Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, Müncheberg, Ghana

³Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Soil Landscape Research, Müncheberg, Germany

⁴Catholic University of Louvain, George Lemaitre Centre for Earth and Climate Research, Louvain, Belgium

Measuring carbon (C) fluxes towards a complete C balance in a soil-crop-atmosphere system allows a faster and more precise evaluation of climate and land use effects than common field experiments. However, it requires the help of process-based modelling in cases where some relevant C fluxes cannot be separated using measurements and to predict hypothetical states of the system which are beyond the power of field experiments. In this context, little has been done to quantify the role of erosion on the function of soil as a C sink or source so far. In a field manipulation experiment (CarboZALF-D) on the C budget at different erosion-induced transient states of soils in the undulating landscape of North-eastern Germany (hummocky ground moraine) high-frequency data of C fluxes gross primary production (GPP), ecosystem respiration ($R_{eco}$) and net ecosystem exchange (NEE as the difference between GPP and $R_{eco}$) were available for a maize crop. We used the MONICA model to analyse the C fluxes. MONICA has been successfully tested for maize yield predictions across a range of different environments and against long-term soil carbon dynamics in various crop rotation experiments. From the conceptual point of view, MONICA should be able to reflect the influence of soil properties and weather on actual CO₂ fluxes and crop growth and successfully predict cumulative CO₂ fluxes, CO₂ budgets and biomass yields at three different landscape positions: hill top (Albic Cutanic Luvisol, erosion neglectable), slope (Calcic Cutanic Luvisol, slight erosion and Calcaric Regosol, strong erosion), and hill foot (Endogleyic Colluvic Regosol, deposition). In this exercise we show that MONICA reproduces NEE as GPP – autotrophic respiration – heterotrophic respiration) of a maize stand in the range of the measured values, although at a small temporal resolution considerable differences are noted for the individual CO₂ fluxes. However, in a method intercomparison the lack of prediction accuracy is compensated by the additional information provided by the model on C fluxes in times when measurements were limited. The prediction of biomass production at the different landscape positions, however, did not live up to the expectations, which is due to several limitations: A point model, MONICA lacks important input information on laterally in- and outflowing sub-surface water into the soil column whose water dynamics is additionally influenced by fluctuating groundwater levels at the hill foot position. Secondly, at strongly inclined positions, where strongly eroded soils exist, nutrient deficiency beyond nitrogen (magnesium, potassium, phosphorus) additionally add to the growth-reducing factors which are not captured in the MONICA model. In summary, it seems that the unsatisfying model results are explained by the insufficient acquisition of growth-relevant soil properties and their three-dimensional distribution rather than the incapable model which was not constructed for this level of detail in the first place. However, to start with, we are able to show that the observed soil water contents at the different positions - if provided as an input to MONICA - may explain a considerable part of the yield differences across the landscape and that stepwise integration of growth-relevant soil properties and their consequences for different processes in the soil-plant-atmosphere system gradually improves the model performance.
Limitations of two energy balance closure parametrizations

F. Eder<fnref n="1" />,<fnref n="2" />, F. De Roo<fnref n="1" />, K. Kohnert<fnref n="1" />,<fnref n="3" />,<fnref n="4" />, R. L. Desjardins<fnref n="5" />, H. P. Schmid<fnref n="1" />, M. Mauder<fnref n="1" />,<fnref n="2" />

Tower-based eddy-covariance (EC) measurements usually do not close the energy balance, because they underestimate the turbulent heat fluxes. We tested two energy balance closure parametrizations that were suggested to correct the measured EC fluxes. For this purpose, we used tower data from three sites of the Bavarian Alps / pre-Alps Observatory of the TERENO programme and surface-layer airborne measurements from the Canadian Twin Otter research aircraft. The non-closure of the energy balance of the aircraft data was estimated from the flux contributions of turbulent structures larger than 2 km. The first parametrization approach, by Huang et al. (2008), is based on large-eddy simulation and was developed for horizontally homogeneous convective boundary layers. It is neither applicable to our tower-based EC measurements nor to the aircraft data, because its grid resolution is not sufficient for modelling surface-layer turbulence. However, for two of the three sites, we could at least confirm the suggested dependence of the energy balance closure on friction velocity. The second approach, by Panin and Bernhofer (2008), is empirical and focuses on landscape-level roughness heterogeneities that are expected to induce secondary circulations. It only gives a rough estimate of the energy balance closure, because besidessurface roughness it does not consider any other feature of landscape-scale heterogeneity, such as surface temperature, surface moisture or topography. Moreover, the meteorological conditions are not taken into account. Nevertheless, the parametrization of Panin and Bernhofer (2008) works better for the sites considered here and clearly shows that the non-closure of the energy balance is related the heterogeneity of the surrounding landscape.

Huang J, Lee X, Patton E (2008) A modelling study of flux imbalance and the influence of entrainment in the convective boundary layer. Boundary-Layer Meteorol 127:273-292

Panin GN, Bernhofer Ch (2008) Parametrization of turbulent fluxes over inhomogeneous landscapes. Izvestiya Atmos Oceanic Phys 44:701-716

<footnote n="1">¹Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany</footnote>

<footnote n="2">²Karlsruhe Institute of Technology (KIT), Institute of Geography and Geoecology (IfGG), Karlsruhe, Germany</footnote>

<footnote n="3">³Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany</footnote>

<footnote n="4">⁴University of Bayreuth, Department of Micrometeorology, Bayreuth, Germany</footnote>

<footnote n="5">⁵Agriculture and Agri-Food Canada, Ottawa, Canada</footnote>
Eddy covariance CO2 and CH4 fluxes in a rewetted fen in NE Germany

D. Franz¹, E. Larmanou¹, K. Kohnert¹, A. Serafimovich¹, F. Koebsch¹, T. Sachs¹

¹GFZ Potsdam, Inorganic and Isotope Geochemistry, Potsdam, Germany

Carbon dioxide (CO2) and methane (CH4) are the most abundant greenhouse gases after water vapor (H2O). Considerably high emissions of CO2 are known from drained and degraded peatlands. Restoring degraded peatlands is expected to reduce their greenhouse gas contribution to the atmosphere in the long term although CH4 release may increase, especially in the first years after rewetting. To inform and improve management decisions, the effect of restoration has to be quantified and greenhouse gas dynamics following re-wetting have to be understood.

Using the eddy covariance (EC) technique we investigate methane and carbon dioxide flux dynamics between the atmosphere and a highly degraded minerotrophic fen grassland, which was flooded in 2004/2005. The study site is located in the Peene River valley (53°52'N, 12°52'E), NE Germany, and part of the Terrestrial Environmental Observatories Network (TERENO) spanning across Germany. Water table fluctuates between 30-80 cm and the area is densely covered by several helophytes and hydrophytes typical for this stage of rewetting. We used the LI-7200 enclosed CO2/H2O and LI-7700 CH4 analyzers. The usual biometeorological data were logged continuously.

We will present flux data covering one year since the system was newly established. Previous measurements at the study site by a steady state flow-through chamber system revealed continuing high methane release, especially during warm periods. Thus, the climate impact of the fen is still not declining after 9 years of rewetting.
# Foehn is snow-eater: numerical analysis of snowmelt and CO₂ exchange processes at pre-alpine grassland sites

G. Katata¹, M. Mauder¹

¹Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Garmisch-Partenkirchen, Germany

The timing of snowmelt plays an important role in determining the variability of CO₂ exchanges over the growing season. Snow physics exhibit a high level of complexity and therefore a sophisticated process-based snow model is needed to obtain realistic results. In the present study, an existing multi-layer atmosphere-SOiL-VEGetation model (SOLVEG) developed by the authors was modified to simulate snow and frozen soil processes. Heat and liquid water transported within a multi-layer snow structure scheme, and freeze-thaw process of soil water was incorporated into the model. The modified model was applied to two pre-alpine grassland sites named Graswang and Fendt in TERestrial ENvironmental Observatories (TERENO) networks in Germany and compared to observational datasets during the wintertime. The modified model reproduced the overall temporal changes in observations of momentum, surface energy, and CO₂ fluxes, albedo, physical snow depth and surface temperature, and soil temperature and moisture. Our simulations demonstrated that foehn winds, a southern warm and dry downslope wind of the Alps, strongly enhanced snow melting due to large negative sensible and positive latent heat fluxes. Soon after the snow melted due to foehn winds, CO₂ assimilation immediately occurred even in the middle of winter season. The overall wintertime Net Ecosystem Exchange (NEE) was estimated and the part of NEE can be attributed to increased growing season length due to enhanced snow-melting under foehn conditions.
# On the benefit of driving Large-Eddy Simulation with spatially resolved surface fluxes derived from environmental response functions

F. De Roo¹, S. Huq¹, S. Metzger²,³, K. Xu⁴, A. Desai⁴, M. Mauder¹,⁵

¹Karlsruhe Institute of Technology, Atmospheric Environmental Research, Garmisch-Partenkirchen, Germany

²National Ecological Observatory Network, Fundamental Instrument Unit, Boulder, United States

³University of Colorado, Institute for Arctic and Alpine Research, Boulder, United States

⁴University of Wisconsin Madison, Department of Atmospheric and Oceanic Sciences, Madison, United States

⁵Karlsruhe Institute of Technology, Institute of Geography and Geoecology, Karlsruhe, Germany

Large-Eddy Simulation (LES) is well-suited for studying turbulence in the atmospheric boundary layer under controlled conditions. However, for LES studies in heterogeneous terrain it is important to accurately prescribe the surface conditions. Environmental response functions (ERF) allow a spatially explicit regionalization of the surface heat fluxes from airborne or tower-based flux measurements. The surface data from the ERF have high spatial resolution (100 m) and exhibit temporal variation during the course of the day, compared to the static and more coarsely resolved surface data obtained from satellite measurements. We run a series of virtual LES experiments, driven by the ERF-derived surface fluxes, and compare the results with LES driven by MODIS surface temperature and enhanced vegetation index data. We evaluate our simulations with vertical profiles of temperature, humidity and eddy-covariance data from the tall tower in Park Falls, Wisconsin, at measurement heights of 30, 122, and 396 meters.
# Coupling of Carbon and Water Cycles over Multiple Time and Spatial Scales in Australian Savannas

M. Harahap¹

¹University of Technology, Sydney, School of Environment, Sydney, Australia

In light of recent concerns of climate change, it is important to conserve natural ecosystems such as savannas that contribute to binding the increasing additional carbon dioxide in our atmosphere due to anthropogenic activities. Because of the vast spatial extent of savannas, they account for approximately 25% global productivity (GPP), this makes them a key terrestrial biome since they play a crucial role in the sequestrian of additional carbon (C) from the anthropogenic emissions into the future and are an important source of carbon storage. Therefore, there is a current need to quantify and model that carbon capture and storage capacity accurately since it is vital in predicting the evolution of the savannas, weather and climate. The efficiency of savannas is estimated by land surface models, such as Australia's CSIRO Atmosphere Biosphere Land Exchange Model (CABLE) and the Soil-Plant-Atmosphere (SPA) model, that include many factors regulating productivity and these models of primary production in terrestrial ecosystems cannot rely on a single limiting factor but instead must consider multiple potentially limiting coupled processes on multiple time and spatial scales. Spatial heterogeneity assures that exchange processes and concentration gradients commonly exhibit a complex three-dimensional structure. Driving mechanisms of climate dynamics and landscape evolution operate on a variety of time scales from diurnal to season to yearly but instrumental measurements do not capture the full range of time scale variability and so the models have limitations in the uncertainty of climate representations in the data. The models are validated against observed field flux measurements of productivity to seven OzFlux sites on a spatial sub-continental scale rainfall gradient of more than 1100km in length, known as the North Australian Tropical Transect (NATT) in Australia.

The aim of the research is to reduce uncertainty and promote precision of land surface models (using CABLE and SPA as a representative) in predictions of heat, water and CO₂ fluxes between the atmosphere and vegetation. There is a need to understand the dynamic relationship between meteorological climate variables and the savannas in order to accurately estimate savanna GPP and to contribute to better savanna data inputs into capable models that focus on estimating global GPP values. We also aim to increase the soundness of land surface models in simulation of plant future responses to climate change and CO₂ increase. To assess the possible future states of Australian savanna landscapes we will use output from the CSIRO climate model (Mk2) as input for the models. The CSIRO Mk2 model is a fully coupled atmosphere/ocean model that includes dynamic sea ice and soil-canopy models and has been shown to provide good agreement with historic Australian rainfall dynamics. We will use several IPCC climate change scenarios from Global Circulation Model outputs for the future projected climate (IPCC Special Report Emissions Scenarios, 2000) such as the business-as-usual IS92 scenario., the best case scenario (B2), and worst case scenario (A2) then input these projections into the modified CABLE to evaluate how the present savanna landscape may respond to projected changes in future climate.

This justifies the direction and scope outlined in this research, as this project will identify the gaps in present models used to project climate and improve them to ultimately dynamically generate current, past and future savanna vegetation patterns and responses. Not only would this work improve and validate the models against observations over fine spatial and temporal resolutions (NATT) of the key processes of carbon and water fluxes, but it also improves the model's capability in simulating and predicting the interactive effects of climate change and CO₂ increase on the savannas function. Hopefully the models will provide robust future estimates of carbon and water that will aid our management of savannas to ensure viable water resources and carbon sequestration, to provide tools for land managers to account for the consequences of climate change and elevated atmospheric CO₂ concentrations on ecosystem viability and hopefully inform the policy decision makers on the importance on conserving the savannas natural ecosystem. As this project deals with the environmental sustainability of Australian ecosystems, it will be of considerable social benefit for Australia.
# Interactions between climate, soil, vegetation, animals in a sahelian rangeland. Impact on organic matter mineralisation and natural NO emissions to the atmosphere

C. Delon<fnref n="1" />, E. Mougin<fnref n="2" />, M. Diawara<fnref n="2" />, P. Hiernaux<fnref n="2" />, M. Grippa<fnref n="2" />, L. Kergoat<fnref n="2" />, D. Serça<fnref n="1" />, C. Galy-Lacaux<fnref n="1" />

The Nitrogen (N) cycle is closely linked to water and carbon cycle, and participates to surface-atmosphere interactions. Modelling studies aim to simulate the various processes involved in these exchanges, by linking hydrology, vegetation, and biogeochemistry, in an integrated model. Natural (biogenic) emissions of nitrogen oxide (NO) from soils to the atmosphere result from biogeochemical processes in the soil and at its surface. These processes are governed by temperature and moisture conditions, directly linked to precipitations, and by the quantity of organic matter, linked to the quantity of vegetation, the presence of livestock or not, and the fertilization. In the Sahel particularly, where the soil moisture content is very low at the end of the dry season, NO emissions depend strongly on soil moisture. When the first rains fall at the beginning of the wet season, soil moisture increases sharply, until reaching a threshold value above which the microbial population can develop, and the microbial activity generating nitrogen within the soil is reactivated. NO emissions to the atmosphere result from the microbial decomposition of organic matter, and present important peaks at the beginning of the wet season (Delon et al., 2012).

In Sahelian soils, the organic matter decomposition is very efficient at the onset of the wet season because part of the litter has been buried during the dry season by livestock trampling, and is rapidly decomposed when soil moisture is sufficient.

This work is an attempt to provide seasonal variation of biogenic NO emission fluxes in a sahelian rangeland in Mali (Agoufou, 15.34° N, 1.48° W) for several years (2004 - 2008).

The link between NO production in the soil and NO release to the atmosphere is investigated in this study, by taking into account vegetation litter production and degradation, microbial processes in the soil, emission fluxes, and environmental variables influencing these processes, using a coupled vegetation-litter decomposition-emission model. This model includes the Sahelian-Transpiration-Evaporation-Productivity (STEP) model (Mougin et al., 1995) for the simulation of herbaceous, tree leaf and fecal masses, the GENeral DEComposition (GENDEC) model ((Moorhead & Reynolds, 1991) for the simulation of the buried litter decomposition, and the NO emission model (Delon et al., 2007) for the simulation of the NO flux to the atmosphere.

The integrated model takes into account the interaction between climate and vegetation growth and decay, animal impacts on aboveground herbage mass variation through ingestion and trampling, and NO emissions. Furthermore, N uptake by plants during the wet season is simulated and related to the decrease of NO emissions from soils at that season.

The several years of simulation allow the quantification of seasonal and yearly variation of biogenic NO variations, with a strong insight in the coupling between different processes involved in the N cycle at the soil-atmosphere interface in semi arid regions.

<footnote n="1">¹CNRS/Université de Toulouse, Laboratoire d'Aérologie, Toulouse, France</footnote>

<footnote n="2">²CNRS/IRD/Université de Toulouse, Geosciences Environnement Toulouse, Toulouse, France</footnote>
# Water as dominant driver of heat impacts in black locust and Douglas-fir trees

N. Ruehr¹, A. Gast¹, C. Weber¹, B. Daub¹, A. Arneth¹

¹KIT, Garmisch-Partenkirchen, Germany

Heat induced droughts are increasing globally, impacting productivity and survival of trees. However, most of our process knowledge on the effects of heat waves originates from single-driver experiments focusing on the effects of soil drought, but largely neglecting changes in temperature and vapor pressure deficit. This study, therefore, investigates the combined effects of heat and drought on tree water and carbon dynamics.

Douglas-fir and black locust trees were grown in large pots under ambient temperature and humidity conditions and watered according to the long-term monthly average in two environmentally controlled compartments of a greenhouse facility. Two heat waves (H1 and H2) were simulated (+10°C; 14-16 days), followed by two recovery phases (R1 and R2) during summer 2013. To study the effects of water availability, watering was reduced by 40-60% for half of the trees per species (drought and heat-drought treatment).

The dominant effect of heat on plant water status was confirmed by large increases in transpiration rates when relative extractable soil water content (RSW) was > 40%. Black locust trees quickly depleted soil water resources (RSW < 30%), causing pronounced tree water deficits and photosynthetic rates to decrease by up to 95% compare to the control. During the recovery phases, tree water storage refilled quickly and photosynthetic rates reached the control values in R1, however, lasting damaging effects became apparent during R2, with photosynthetic rates remaining 20-40% below the control. In Douglas-firs, coupled heat-drought caused mild soil water stress (RSW > 60%) that resulted in significant tree water deficits only during H2, when daily temperature maxima were > 40°C and VPD > 4 kPa, along which photosynthesis declined by 60% in the heat-drought and by 40% in the heat treatment.

In summary, heat stress significantly affected tree water relations and caused a linear decline in water-use-efficiency (WUE = assimilation / transpiration; R² = 0.61), which was similar overall treatments and species. This indicates that the impact of heat waves may largely depend on tree water demand and the related depletion of soil water resources.
# Isolating the effect of groundwater dynamics on subsurface-land surface interactions

M. Rahman<fnref n="1" />, S. Kollet<fnref n="2" />, M. Sulis<fnref n="1" />

In the terrestrial hydrological cycle, the land surface acts as the interface between the subsurface and atmosphere. It is important to study the interconnections between different processes associated with these compartments (i.e., subsurface, land surface, and atmosphere) to understand the overall mechanisms of the coupled water and energy cycles. A new concept of dual-boundary forcing for the land surface processes is proposed to explain and quantify the interactions between compartmental mass and energy balance components at different space-time scales. According to this concept, atmosphere and groundwater act as the upper and lower boundary conditions, respectively, for the land surface mass and energy balance components. The space-time patterns of land surface mass and energy fluxes can be explained by the variability of the dominating boundary condition for the exchange processes, which is determined by moisture and energy availability. In order to substantiate this concept, a fully coupled subsurface-land surface model ParFlow.CLM is applied over the Rur catchment, which is located in western Germany and has an area of ~2,400km<fnref n="2" />. A comprehensive comparison between observed and simulated fluxes and states demonstrates the model's capability to represent adequately the processes of the coupled water and energy cycles. Geostatistical and spectral analysis of the model results show the coherence between different processes of the coupled water and energy cycles at various space-time scales, which supports the proposed dual-boundary forcing concept. In order to isolate the influence of temporal dynamics of the lower boundary condition on hydrological cycle, subsequently a spatially distributed, temporally constant groundwater table is prescribed to ParFlow.CLM. The comparison of different fluxes from these two model runs illustrates the effect of the lower boundary condition on the coupled water and energy cycles. The results demonstrate that groundwater table depth modulates the influence of the temporal dynamics of lower boundary condition on land surface processes (e.g., latent heat flux). Using wavelet transform analysis it is shown that the temporal variability of land surface processes (e.g., soil moisture and surface runoff) increases at different time scales (on the order of 10⁰-10¹days) in case of the temporally constant lower boundary condition. Cross wavelet transform suggests that this enhanced temporal variability of land surface processes can be attributed to atmospheric forcing (e.g., precipitation). From these results it appears that the influence of atmospheric forcing (i.e., the upper boundary condition) on land surface processes increases in the absence of temporal dynamics of the groundwater table (i.e., the lower boundary condition).

<footnote n="1">¹Meteorological Institute, University of Bonn, Bonn, Germany</footnote>

<footnote n="2">²Institute for Bio- and Geosciences, Agrosphere, Research Centre Jülich, Jülich, Germany</footnote>
# The influence of dynamic vegetation models including harvest on the energy fluxes and the feedback effects between weather and land surface models

C. Klein¹, C. Biernath¹, C. Thieme¹, F. Heinlein¹, E. Priesack¹

¹Helmholtz Zentrum München, Institut für Bodenökologie, Neuherberg, Germany

Recent studies show that uncertainties in regional and global weather and climate simulations are partly caused by inadequate descriptions of the soil-plant-atmosphere system. Particularly relevant for the improvement of regional weather forecast are models which better describe the feedback fluxes between the land surface and the atmosphere, which influences surface temperature, surface air pressure and the amount and frequency of precipitation events. Aim of this study was to examine the influence of different management strategies and the use of dynamic vegetation models to energy fluxes at the land surface boundary layer. For this study the land surface model Expert-N was used, which is fully coupled to the "Regional Climate and Weather Forecast Model" (WRF). Where the standard model NOAH distinguishes between vegetation class specific monthly changing soil cover values (leaf area index) and defined soil characteristics, Expert-N is an ecosystem model that allows the application of more mechanistic soil and plant sub-models including the management of soil and vegetation and effects of water and nutrient availability on plant growth are considered. The influence of different harvest scenarios on the energy fluxes is discussed. The simulation shows the high impact of vegetation management on the energy fluxes which caused significant differences between weather characteristics such as the simulated surface temperatures and precipitation events on the regional scale. Therefore, we conclude that weather forecast on the regional scale could be significantly improved by modeling approaches that better describe the dynamic of vegetation growth.
Improvement of forecasts of pollen emissions by birches on regional scale.

C. Biernath<fnref n="1" />, C. Klein<fnref n="1" />, J. Hauck<fnref n="1" />, F. Heinlein<fnref n="1" />, C. Thieme<fnref n="1" />, J. C. Munch<fnref n="1" />, I. Beck<fnref n="2" />, S. Breitner<fnref n="3" />, J. Cyrys<fnref n="3" />, S. Gilles-Stein<fnref n="2" />, A. Peters<fnref n="3" />, K. Wolf<fnref n="3" />, A. Schneider<fnref n="3" />, C. Traidl-Hoffmann<fnref n="2" />, E. Priesack<fnref n="1" />

Patient targeted medication could be improved if forecasts of the allergenic potential of pollen emissions and the actual allergenic potential are precise on regional scale. The allergenic potential is determined by the biochemical composition. In plant tissue the biochemical composition may change within hours due to resource availability for plant growth and plant internal nutrient re-mobilization, and the organ specific demand.

These processes highly depend on both, the environmental conditions and the development stage of a plant.

Therefore, dynamic plant models that consider the dependence of the chemical composition of tissue on the development stage of the plant embedded in process-based ecosystem models seem promising tools to improve forecasts of pollen emissions; however, today dynamic plant growth is widely ignored in simulations of atmospheric pollen loads.

In this study we analyze to which extent frequently applied temperature sum models could simulate onset of flowering of birches on regional scale in Bavaria. Temperature sum models integrate average temperatures above a base temperature below which no further bud development is assumed. In this study we achieved the best simulation results using base-temperatures below 0°C, which is much lower as frequently used base temperatures. A more regional calibration of the models to sub-regions in Bavaria with comparable climatic conditions further improved the simulation results indicating the need for a more local adjustment of birch phenology models. The simulation results may be biased if the base temperatures are assumed constant for all birches and are transferred to other regions with different climatic or environmental conditions, or when applied to extrapolate birch pollen seasons to future climate conditions.

<footnote n="1">¹Helmholtz Zentrum München, Institute of Soil Ecology, Oberschleißheim, Germany</footnote>

<footnote n="2">²Technische Universität München, Institute for Environmental Medicine, UNIKA-T, München, Germany</footnote>

<footnote n="3">³Helmholtz Zentrum München, Institute of Epidemiology II, München, Germany</footnote>
# Implementation of Spaceborne Canopy Height Data in the High Resolution WRF Model

J. Hong¹, J. Lee¹, S.-Y. Hong¹

¹Yonsei University, Department of Atmospheric Sciences, Seoul, Korea, Republic of

Vegetation canopy regulates weather and climate by modifying roughness, albedo, and longwave radiation at the surface. In particular, vegetative surface is a major source to reduce wind speed and so it is important to provide surface roughness parameters such as zero-plane displacement height and roughness length to climate and NWP models for better reproducing wind and its related divergence of air flows. Recently, airborne canopy height data has been released and these data has been implemented into the high resolution WRF model. WRF version 3.5 is used to investigate impacts of inclusion of observed canopy height data on reproducing rainy season over Korea and South America continent. The physics package used in this study employs the WRF single-moment 6-class (WSM6) microphysics scheme, the new Kain-Fritsch cumulus parameterization scheme, the Yonsei University planetary boundary layer (YSUPBL), a simple cloud-interactive radiation scheme, and Rapid Radiative Transfer Model (RRTM) longwave radiation schemes, and Noah-MP land-surface model. The implementation of spaceborne canopy height data decreases latent heat fluxes over Korean peninsula and thus reducing excessive orographic precipitation which have been generally reported in the NWP models and GCM.
# Modelling climate change impacts on crop growth and yield quality based on explicit simulation of plant internal transport processes

F. Heinlein¹

¹Helmholtz Zentrum München GmbH, Soil Ecology, Neuherberg, Germany

The yield of agricultural plants will be influenced by future climate change as well as by the changing composition of the atmosphere. In order to better estimate these effects new, mechanistic plant growth models are needed. It is desirable that these models dynamically reproduce the plants' reactions to modified climate state variables like water availability, temperature and atmospheric CO2-concentration. In particular, to better describe the crop response to more strongly changing water availability an explicit simulation of plant-internal water and solute transport processes in xylem and phloem has to be executed.

Our existing water transport model uses two coupled 1-D Richards equations to calculate water transport in the plants and in the soil. This model has already been successfully applied to single *Fagus sylvatica* L. trees. At present it is adapted to agricultural plants such as maize.

The simulation of the water transport in the plants requires a representation of the plants' architectures, i.e. the flow paths. Aboveground plant structures are obtained from terrestrial laser scan (TLS) measurements at different development stages. These TLSs have been conducted at the TERENO research farm Scheyern and at the lysimeter facilities of Helmholtz Zentrum München. Additionally, an L-system model, which produces plant architectures at different growths stages, is used to simulate the aboveground part of the plants. In a next step this model will be extended to belowground plant architectures.

Furthermore, the quality of the explicit water flow model has to be evaluated with measurements. Therefore, the Heat-Ratio-Method has been employed to directly measure sap flow in larger maize plants during a two-months-period in summer 2013 with a temporal resolution of 10 minutes. Thus, the plants' transpiration can be assessed. Water losses from soil are determined by weighing lysimeters, which allow for the calculation of evapotranspiration.

Plant growth, including transpiration and evapotranspiration is also simulated with the modelling system Expert-N. This framework facilitates the combination of different models and sub-models to simulate plant growth and crop management as well as water, heat, nitrogen and carbon dynamics. Two different sub-models (CERES and SPASS) are used to simulate plant growth, which includes plant transpiration. Modeled and measured actual transpiration and evapotranspiration are compared and discussed.

Measured sap flow rates show clear diurnal cycles and are strongly controlled by the particular weather, especially by temperature, radiation and relative humidity. CERES and SPASS are only partly suited to model plant water dynamics as measured. This confirms the importance of explicit water transport and transpiration models.
# A new method for continuously measuring the d¹³C of soil CO₂ concentrations at different depths by laser spectrometry

B. Longdoz<fnref n="1" />, F. Parent<fnref n="1" />, C. Plain<fnref n="2" />, M. Maier<fnref n="3" />, D. Epron<fnref n="2" />

The transfer mechanisms of carbon in the soil-plant-atmosphere continuum, in particular for soil CO₂ production, have yet to be identified. Nor are the processes linking these transfers fully understood. To partially address this lack of information, one approach is to simultaneously measure soil CO₂ concentrations in the air-filled pores, soil CO₂ efflux and their respective isotopic signatures (δ¹³C-CO₂). To quantify soil air ¹³CO₂ and ¹²CO₂ concentrations, we adapted a method based on CO₂ diffusion from soil pores. Tubes with a highly gas-permeable membrane wall were placed horizontally at different depths in the soil. Air was sampled automatically from the tubes and injected through a diluting system into a tuneable diode laser absorption spectrometer. The CO₂ and δ¹³C-CO₂ vertical profile was thus obtained at hourly intervals. Our tests proved the absence of fractionation in the membrane tubes for δ¹³C-CO₂. Subsequently, we set up field experiments for two forest soils which showed that natural soil CO₂ concentrations and d¹³C-CO₂ were not significantly affected by the system. While d¹³C-CO₂ in air-filled pores below 5 cm was constant over three days, we observed large diurnal variations in d¹³C-CO₂ efflux. However, the average difference between the two measurements was close to -4.4‰, which supports steady-state diffusion. This new method seems to be a very effective way to measure the d¹³C-CO₂ profile of the soil atmosphere, and reveals that fractionation during diffusion is the main process that affects the d¹³C-CO₂ of the soil CO₂ efflux on a daily timescale while advection may account for within-day variations.

<footnote n="1">¹INRA, UMR Forest Ecology & Ecophysiology, Champenoux, France</footnote>

<footnote n="2">²Université de Lorraine, UMR Forest Ecology & Ecophysiology, Vandoeuvre les Nancy, France</footnote>

<footnote n="3">³University of Freiburg, Chair of Soil Ecology, Freiburg im Breisgau, Germany</footnote>
# Horizon Partitioning of Soil CO2 Sources and their Isotopic Composition (13C) in a Pinus Sylvestris Stand

S. Goffin<fnref n="1" />, F. Parent<fnref n="2" />, C. Plain<fnref n="3" />, M. Maier<fnref n="4" />, H. Schack-Kirchner<fnref n="4" />, M. Aubinet<fnref n="1" />, B. Longdoz<fnref n="2" />

The Flux-Gradient Approach (FGA) allows the vertical distribution of gas turnover and production in the soil to be calculated. This approach has been used successfully for greenhouse gases, such as CO2, CH4 and N2O but not yet for the stable isotope composition of soil CO2 (□13CO2), although this subject has become increasingly important. In this study, an innovative experimental set-up, based on the Membrane Tube Technique (METT) and adapted to C stable isotope recording, was used to carry out in situ measurements in a Scots pine forest soil in Hartheim, Germany. Continuous measurements of soil CO2 and □13CO2 efflux and of soil air CO2 and □13CO2 concentration were combined with the FGA to investigate the vertical distribution and temporal variability in CO2 production (P) and its isotopic signature (□13P). The FGA gave consistent values for P and □13P in each soil horizon, except for the O1 horizon where diffusive transport seemed to be affected by atmospheric turbulence. The results showed that P was subjected to a significant vertical stratification, whereas no significant □13P vertical variation was found. The surface soil water content (SWC) was reported to be critical to the accurate partitioning of P between the topsoil layers. In addition, significant temporal P and □13P variations were found in the most productive horizon, the first being best explained by the soil temperature, the second depending on the moisture conditions. No visible □13P climatic dependence was visible in the measured surface flux isotopic composition (□13Fs). Finally, in the litter layer (O1), a significant correlation was found between P and friction velocity. This was attributed to the predominance of non-diffusive transport in the litter layer.

<footnote n="1">¹Université de Liège–Gembloux Agro-Bio Tech, Unit of Biosystem Physics, Gembloux, Belgium</footnote>

<footnote n="2">²INRA, UMR Forest Ecology & Ecophysiology, Champenoux, France</footnote>

<footnote n="3">³Université de Lorraine, UMR Forest Ecology & Ecophysiology, Vandoeuvre les Nancy, France</footnote>

<footnote n="4">⁴University of Freiburg, Chair of Soil Ecology, Freiburg im Breisgau, Germany</footnote>
# Modelling water flow in beech trees based on 3D plant architecture derived from laser scans

E. Priesack¹

¹Institute of Soil Ecology, Helmholtz Center Munich, Oberschleissheim, Germany

We apply a functional-structural model of tree water flow to single old-growth trees of a temperate broad-leaved forest stand. Roots, stems and branches are represented by connected porous cylinder elements that are divided into the inner heartwood cylinders surrounded by xylem and phloem.

Xylem water flow is simulated by applying a non-linear Darcy water flow in porous media driven by the water potential gradient according to the cohesion-tension theory. The flow model is based on physiological input parameters such as the hydraulic conductivity, stomatal response to leaf water potential and root water uptake capability and, thus, can reflect the different properties of tree species.

Actual root water uptake is calculated using a Darcy law based on the gradient between root xylem water potential and rhizosphere soil water potential and by simulation of soil water flow using Richards equation.

A leaf stomatal conductance model is combined with the hydrological tree and soil water flow model and a spatially explicit three-dimensional canopy light model. The structure of the canopy and the tree architectures are derived by applying an automatic tree skeleton extraction algorithm from point clouds obtained by applying a terrestrial laser scanner allowing an explicit representation of the water flow path in the stem and branches. The high spatial resolution of the root and branch geometry and connectivity makes the detailed modelling of the water use of single trees possible and allows for the analysis of the interaction between single trees and the influence of the canopy light regime on the water flow inside the xylem.

The model can be applied at various sites and to different tree species, allowing the up-scaling of the water usage of single trees to the total transpiration of mixed stands.

Examples are given to reveal differences between diffuse- and ring-porous tree species and to simulate the diurnal dynamics of transpiration, stem sap flux, and root water uptake observed during the vegetation period at different sites.
# Interception and resulting below canopy patterns in a mixed beech forest in central Germany

A. Hildebrandt¹, J. Friesen²

¹Friedrich Schiller University Jena, Institute of Geoscience, Jena, Germany

²Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany

Water can reach the forest floor through several pathways, as stemflow and throughfall, both being the source of substantial heterogeneity in water input at the soil surface. So far there have been only few combined measurements, to assess at the same time the creation of heterogeneity by stemflow and throughfall and their relation to soil moisture patterns.

We investigate in a beech-dominated forest in central Germany the dynamics throughfall, stemflow and topsoil water content. The site belongs to the Terrestrial Environmental Observatories (TERENO), Harz/Central German Lowland Observatory. We measured net precipitation on an event basis, and separated it into subplots covered with oak and beech. We also assessed soil water content using a wireless sensor network (SoilNet) at over 130 locations. The measurement points were arranged at increasing distances from the tree trunks. Data were collected over a nine months period, including 10 weeks of intensive event based throughfall and stemflow monitoring.

Interception loss did not differ substantially between locations under oak and beech, although the partitioning between stemflow and throughfall varied substantially, particularly during larger precipitation events. During most of the observed precipitation events, the correlation length of throughfall was on the order of the average tree distance. The degree of organization decreased with interception: Larger events, with smaller interception, were characterized by short correlation lengths. These were at the same time the events with a larger proportion of stemflow.

Stemflow also modified patterns of soil water content near the trees compared to further away. However, this influence was only of short duration, particularly during in the growing season, probably due to root water uptake and/or preferential flow paths.

Our results indicate that while canopy type does not appreciably change interception, it may strongly modify the degree of heterogeneity in patterns of net precipitation and hence available water for infiltration.
# Implementation and validation of high-resolution and plant-specific physiological parameterizations in a terrestrial systems modeling platform

M. Sulis<fnref n="1" />, M. Langensiepen<fnref n="2" />, P. Shrestha<fnref n="1" />, S. Kollet<fnref n="3" />,<fnref n="2" />, C. Simmer<fnref n="1" />

Vegetation is the interface layer between the soil and atmosphere compartments of the terrestrial water, energy, and matter cycle. It exerts a major impact on both climate and weather dynamics by modifying the radiative, momentum, water, and energy balance between the land surface and the planetary boundary layer. In Earth system modeling platforms, the vegetation is classified by defining plant functional types that do have measurable leaf physiology and carbon allocation. In such representation, agricultural crops are commonly classified as corn, wheat, and soybean by setting time-invariant physiological properties based on estimates published in literature. In this work, a new set of physiological parameters describing the photosynthesis, optical, and aerodynamic properties of two crops, sugar beet and winter wheat, were included in the parametrization of the land surface component of a novel terrestrial modeling platform (TerrSysMP). These leaf-level plant parametrizations were based on a synthesis of extensive field measurement campaigns carried out over several sites located in an agricultural district of the North Rhine-Westphalia region in Germany. The new set of crop-specific parameters were validated using eddy covariance technique (latent heat and sensible heat) at three measurement sites and over multiple years. In addition, to evaluate the impact of such high-resolution information on the evolution of the planetary boundary layer, a series of land surface-atmosphere coupled experiments were performed. The numerical simulations consist of 2-days hindcast semi-idealized runs over the North Rhine-Westphalia domain where a generic crop functional type was replaced with region-specific sugar beet and winter wheat parametrizations.

<footnote n="1">¹Meteorological Institute, University of Bonn, Bonn, Germany</footnote>

<footnote n="2">²Centre for High-Performance Scientific Computing in Terrestrial Systems (HPSC TerrSys), Research Centre Juelich, Juelich, Germany</footnote>

<footnote n="3">³Institute for Bio- and Geosciences, Agrosphere (IBG-3), Research Centre Juelich, Juelich, Germany</footnote>
Is an accurate description of local carbon fluxes in soil-vegetation-atmosphere system
from large scale climate data possible?

S. Venevsky¹

¹Tsinghua University, Center for Earth System Science, Beijing, China

SEVER dynamic global vegetation model (DGVM) was run for 14 Euroflux sites with the large scale NCEP daily climate data as an input for years 1997-2000 and net ecosystem exchange (NEE) calculated and observed were compared. It was shown that daily local NEE flux can be feasibly described by SEVER, using large scale climate data as an input. Possible combinations of linearly-interpolated and not interpolated monthly temperature, precipitation, shortwave radiation and ratio of sunshine hours were tried in order to get a feasible accuracy in NEE values. We found that daily temperature and shortwave radiation data are most essential for reproduction of daily NEE at the Euroflux sites, precipitation and ratio of sunshine hours can be linearly interpolated from their mid-month values. Running means (1 to 30 days) were calculated for simulated and observed values of NEE and correlated for each Euroflux site. The most visible improvement in both the averaged correlation coefficient and the averaged slope of regression for the set of Euroflux sites was seen for 5 days running mean. SEVER DGVM was compared for monthly time step with the Lund-Potsdam-Jena DGVM with an incorporated stochastic weather generator. The test showed that LPJ DGVM has better performance in description of NEE only for three Euroflux sites and for the other ten sites SEVER DGVM outperforms it. This was attributed to the weather generator of LPJ DGVM.
# Separating evaporation from transpiration in winter wheat using high-frequency eddy covariance data

P. Stoy¹, E. Harris¹

¹Montana State University, Land Resources and Environmental Sciences, Bozeman, United States

Evapotranspiration has (ET) declined globally, but it is unclear if transpiration (T), evaporation (E), or both are driving this response. T and E must be quantified to understand the mechanisms driving changes to ET, but are difficult to measure at the plot scale. Here, we apply the method of Scanlon and Kustas (2010, Ag. For. Met 150: 89-99) to estimate T and E from eddy covariance observations of ET using high frequency data and expectations of similarity theory. We find that ET in a Montana wheat field is almost entirely (>90%) attributable to T during the peak growing period and that the ratio E:T is a function of crop growth stage with predictable changes after harvest. T is maintained in this dryland cropping system by progressive root growth until seed is set, after which a rapid shift in E:T favoring E is observed. Opportunities to extend these analyses to TERENO study ecosystems in the Ammer Basin are discussed.
# A Concept for the Development of Spatially Resolved Measurements for Soil Moisture with TEM Waveguides

Y. Lapteva<fnref n="1" />, F. Schmidt<fnref n="1" />, H. Toepfer<fnref n="2" />, J. Bumberger<fnref n="1" />

Soil water content plays a leading role in partitioning water and energy fluxes at the land surface. Furthermore, soil moisture is an important store of water for vegetation. The information about water content in the soil would be very useful in overcoming the challenge of managing water resources under conditions of increasing scarcity in Southern Europe and the Mediterranean region. For collecting data about the water content in soil, it is possible to use remote sensing and groundwater monitoring, built wireless sensor networks for water monitoring. Remote sensing provides a unique capability to get the information of soil moisture at global and regional scales. Wireless environmental sensor networks enable to connect local and regional-scale soil water content observations.

There exist different ground based soil moisture measurement methods such as TDR, FDR, electromagnetic waves (EW), electrical and acoustic methods. Among these methods, the time domain reflectometry (TDR) is considered to be the most important and widely used electromagnetic approach. The special techniques for the reconstruction of the layered soil with TDR are based on differential equations in the time domain and numerical optimization algorithms. However, these techniques are time- consuming and suffering from some problems, like multiple reflections at the boundary surfaces. To overcome these limitations, frequency domain measurement (FDM) techniques could be used. With devices like vector network analyzers (VNA) the accuracy of the measurement itself and of the calibration can be improved. For field applicable methods the reflection coefficient is mathematically transformed in the time domain, which can be treated like TDR-data and the same information can be obtained.

To develop an improved method for determining the soil moisture distribution, a combination of FDM techniques with an increased amount of data is applied. The basic idea is to use four sets of data provided by VNA: the reflection from both sides and the transmission through the transmission line in both directions. However, if the increased information content with three instead of one frequency- dependent value constitutes the input for a layer inversion algorithm, the results are supposed to have a better accordance with the control measurement or the computing time should decrease. Following up the approaches described in the preceding sections a model for the propagation of an electromagnetic wave along transmission line needs to be developed. The model has to contain an expression for the reflection and the transmission coefficients. There are already existed some experiments using the frequency domain data directly as an input for inversion algorithms to find the spatial distribution of the soil parameters. The model that is used represents an exact solution of the Maxwell's equations. It describes the wave propagation in a multi-layered medium, assuming the wave to be transverse electromagnetic (TEM). In the particular case of transmission lines with perpendicularly arranged layer transitions this assumption is very close to reality. Such waveguides and their frequency domain measurements in layered media are promising concerning a development ways working with soil moisture detection.

<footnote n="1">¹Helmholtz Centre for Environmental Research - UFZ, Department Monitoring and Exploration Technologies, Leipzig, Germany</footnote>

<footnote n="2">²Ilmenau University of Technologies, Ilmenau, Germany</footnote>
# Assessment of a Multi Model Ensemble to Forecast the European 2003 Drought

R. Kumar¹, S. Thober¹, L. Samaniego¹

¹Helmholtz Centre for Environmental Research - UFZ, Department Computational Hydro Systems(CHS), Leipzig, Germany

Agricultural droughts are considered among the most catastrophic natural disasters because they have the potential to diminish crop yields causing economic damage or threatening the livelihood of societies (e.g., the European 2003 drought and the 2010/11 Horn of Africa drought, respectively). An agricultural drought occurs if a soil moisture index is falling below a threshold (typically, a quantile that is equaled or exceeded 20% of the time). The capabilities of current drought monitoring systems are two-fold. First, they provide an estimate of current drought (i.e., soil moisture deficit) conditions. Second, they provide a seasonal forecast of drought development. Being able to correctly forecast the extent and intensity of agricultural droughts can help to mitigate their negative effects on the society.

Several drought monitoring and forecasting systems exist for the regional and the continental scale, for instance, the U.S. Drought Monitor (USDM), the European Drought Observatory (EDO), and the African Flood and Drought Monitor (AFDM). These systems combine information from various observational data sources such as ground based meteorological measurements and satellite based remote sensed products to provide the best possible estimate of current drought conditions. Additionally, some of these systems (e.g., AFDM) also incorporate seasonal meteorological forecasts such as CFSv2 to estimate future drought conditions. Meteorological forecasting skill, however, in particular that of precipitation, is limited to a few weeks because of the chaotic behavior of the atmosphere. Ensembles of meteorological forecasts are typically employed to increase the drought forecasting skill because the uncertainty associated with single model simulation outweighs the model capability to correctly estimate the actual evolution of the atmospheric processes. One of the most important challenges in drought forecasting is to understand how the uncertainty in the atmospheric forcings (e.g., precipitation) is further propagated into hydrologic variables such as soil moisture, and from them to forecast variables such as the soil moisture index.

A large atmospheric ensemble has the potential to overcome the aforementioned challenge. The North-American Multi-Model Ensemble (NMME) is the latest collection of a multi-institutional seasonal forecasting ensemble with global coverage. It encompasses more than 100 meteorological data sets from different Numeric Weather Models developed by several institutions. The NMME allows testing the hypothesis that a large meteorological ensemble increases drought forecasting skill at various lead times. In particular, it is investigated if the ensemble is already large enough for achieving a robust drought forecasting by subsequently selecting different sub-ensembles from it and evaluating their forecasting skill. Sub-ensemble selection methods are readily available and have already been successfully applied in the evaluation of ENSEMBLES regional climate models (RCMs) to reproduce observed extreme meteorological indices.

The aforementioned hypothesis is tested for the European 2003 drought event. The modeling period encompasses the period from January 1st to September 30th 2003. The study area ranges roughly from 10°W to 40°E and 35°N to 55°N and covers large parts of the Pan-European domain. The seasonal NMME forecasts are provided at a spatio-temporal resolution of 1° horizontal resolution and monthly values. These are bias corrected and downscaled to daily values and 1/4° resolution to force the mesoscale hydrological model (mHM). Previous research has shown that historic drought events in Germany could be successfully reconstructed by mHM soil moisture fields at approximately 1/32° resolution.

Preliminary results indicate that the full NMME leads to more robust drought statistics than those obtained if only limited (e.g., CFSv2) forecasts are considered. Based on the fact that sub-ensemble selection has proven to be beneficial for increasing the skill of RCMs to reproduce extreme indices, it is expected that a subset of the full NMME ensemble could be found that exhibits at least the same fidelity to forecast the European 2003 drought event as the full ensemble. This would be highly
beneficial because a sub-ensemble will drastically reduce the computational cost of the hydrologic modeling. Overall, the experiences gained within this study will provide useful information to enhance the capabilities of current drought forecasting systems such as AFDM and to develop a first seasonal drought forecasting system over Europe.
# Investigating wintertime hillslope hydrological and snow cover dynamics using a wireless soil moisture and temperature monitoring network and time-lapse digital photography

U. Wollschläger<fnref n="1" />, C. Vogt<fnref n="2" />, S. Kögler<fnref n="1" />, E. Martini<fnref n="1" />

In mountainous catchments, snowmelt may be an important component of the water balance. We apply data from a wireless soil moisture and temperature monitoring network in combination with time-lapse photographs collected over a two-weeks period during winter 2014 from a hillslope in the Schäfertal catchment, lower Harz mountains, to investigate interactions between hillslope-scale snow cover, soil moisture and soil temperature. The time series of digital photographs is evaluated using an automatic algorithm that estimates snow height at the position of several snow stakes placed along the hillslope using the green value of the RGB color cube. Snow heights are then applied to interpret near-subsurface soil moisture and soil temperature dynamics from the same time period including snow accumulation and melt. Even though snow cover was extremely low (less than 10 cm) during winter 2014, the combination of time lapse digital photography, soil moisture and soil temperature monitoring clearly shows the strong influence of the snow cover on subsurface soil moisture and soil temperature dynamics. The shallow snow cover has a strong insulating effect on near-subsurface soil temperatures leaving the soil unfrozen even at air temperatures reaching down to less than -10 °C. The time-lapse photographs, soil moisture and soil temperature observations also show the different snowmelt behavior of the north- and south-exposed slopes, with faster snowmelt on the south-exposed slope being snow-free one day earlier than the slope exposed towards the north. All these observations are important information for future modelling of hillslope and catchment-scale hydrological dynamics.

<footnote n="1">¹Helmholtz Centre for Environmental Research - UFZ, Monitoring & Exploration Technologies, Leipzig, Germany</footnote>

<footnote n="2">²Eberhard-Karls-Universität Tübingen, Tübingen, Germany</footnote>
# Species specific temporal patterns of throughfall and stemflow in the north-eastern German Lowland Observatory (TERENO)

J. Dreibrodt<fnref n="1" />, S. Germer<fnref n="2" />, M. Morgner<fnref n="1" />, A. Güntner<fnref n="1" />, T. Blume<fnref n="1" />

Rain falling on forests is redistributed in the canopy: it is intercepted by the canopy and later evaporated, it falls through canopy gaps or drips from leaves and branches once the interception storage is filled (throughfall (TF)), or it is channeled to the tree stems and delivered to the soil as stemflow (SF). Throughfall is usually the largest fraction, followed by evaporation or stemflow. The amounts and spatial patterns of rainfall redistribution by forest canopies vary for different tree species and can play an important role for soil moisture distribution and subsequently for groundwater recharge. Therefore we quantified the fractions of TF and SF on gross rainfall for different forest types and for different meteorological parameters and rainfall characteristics. This will improve our ability for predicting future impacts of climate and forest structural changes on the water balance of forest stands.

TF was measured at 7 monitoring sites covering different tree species and ages: young and old beech, young oak and young and old pine as dominantly occurring trees. The investigated 2000m<fnref n="2" />-plots are situated in the TERENO observatory in the Müritz-Nationalpark / Germany. TF at each site was collected with 5 trough systems, each consisting of 3 troughs connected to one tipping bucket. The total collecting area per plot was 6.6m<fnref n="2" />. Gross precipitation, i.e. rainfall above or outside of the forest, was evaluated in a nearby forest clearing with an identical setup of 3 troughs. Stemflow was measured for 5-10 trees per site with PVC-collars wrapped around the stems. The collars were connected to tipping buckets.

Canopy structure is likely to have a major influence on TF distribution. The forest structure was characterized by mapping the tree species, stem positions and stem diameters. Seasonal variations of leaf coverage were monitored by ground-based leaf-area index (LAI) measurements. Spatial LAI patterns within a site and possible relations to TF distribution were assessed.

The storage capacity of the canopy can be estimated based on the cumulative precipitation between the onset of rainfall and the onset of TF. Rainfall events were grouped depending on time elapsed since the previous event as a proxy for storage depletion through evaporation, and correlations to delay in TF initiation were examined. The effect of rainfall intensities on these tree species specific time lags was also investigated.

As one of the next steps the TF, SF and soil moisture data from the same sites will be implemented in a hydrogeological model to test several groundwater recharge scenarios.

This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis -ICLEA- of the Helmholtz Association. This study is supported by TERENO infrastructure of the Helmholtz Association.

<footnote n="1">¹Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ, 5.4 Hydrologie, Potsdam, Germany</footnote>

<footnote n="2">²Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V., Potsdam, Germany</footnote>
# Development of Inexpensive Radiation Sensors for Ecosystem Research

H. Mollenhauer<fnref n="1" />, R. Schima<fnref n="1" />, M. Assing<fnref n="2" />, O. Mollenhauer<fnref n="2" />, P. Dietrich<fnref n="1" />, J. Bumberger<fnref n="1" />

The observation and monitoring of ecosystem processes are great challenges in environmental science, due to the dynamic and complexity of such procedures. To describe and understand biotic and abiotic processes and their interaction it is necessary to acquire multiple parameters, which are influencing the natural regime. Essential issues are: the detection of spatial heterogeneities and scale overlapping procedures in the environment. To overcome these problems an adequate monitoring system should cover a representative area as well as have a sufficient resolution in time and space. Hence, the needed quantity of sensors (depending on the observed parameters or processes) can be enormous. According to these issues, there is a high demand on low-cost sensor technologies (with adequate performances) to realize a delicate monitoring platform. In the case of vegetation processes, one key feature is to characterize photosynthetic activity of the plants in detail. Common investigation methods are based on optical measurements. Here photosynthetically active radiation (PAR) sensors and hyperspectral sensors are in major use. Photosynthetically active radiation (solar radiation from 400 to 700 nanometers) designates the spectral range that photosynthetic organisms are able to use in the process of photosynthesis. PAR sensors enable the detection of the reflected solar light of the vegetation in whole the PAR wave band. The amount of absorption indicates photosynthetic activity of the plant. Hyperspectral sensors observe specific parts of the solar light spectrum and facilitate the determination of the main pigment classes (Chlorophyll, Carotenoid and Anthocyanin). Due to absorption of pigments they producing a specific spectral signature in the visible part of the electromagnetic spectrum (narrow-band peaks). If vegetation is affected by water or nutritional deficiency the proportion of light-absorbing pigments is reduced which finally results in an overall reduced light absorption. The resulting spectral signature then differs from usual reflectance patterns and can be used as stress indicator. Hence, reflectances between 550-700 nm are extremely sensitive regarding changing Chlorophyll contents. Both kinds of sensors based on semiconductor technologies whereby the material input can kept on low level. This work presents the development and testing of a practical, rugged, and inexpensive PAR and hyperspectral sensor. The sensors were made from a gallium arsenide phosphide (GaAsP) photodiodes and silicon photodiodes with different interference filters. The testing of the cosine correction and spectral response of the sensors features optimal measuring characteristics in relation to industrial produced sensors. In addition results of recorded long term in-situ data and linear regressions (in comparison to commercial products) show extremely high performances (coefficient of determination higher than 0.99) of the PAR sensors simultaneous to the cost cutting.

<footnote n="1">¹Helmholtz Centre for Environmental Research - UFZ, Department Monitoring and Exploration
Technologies, Leipzig, Germany</footnote>

<footnote n="2">²TETRA Gesellschaft für Sensorik, Robotik und Automation mbH, Ilmenau, Germany</footnote>
# Potentials, Challenges and Applications of Mobile Wireless Ad-hoc Sensor Networks for Environmental Monitoring

J. Bumberger<fnref n="1" />, H. Mollenhauer<fnref n="1" />, P. Remmler<fnref n="1" />, M. Assing<fnref n="2" />, O. Mollenhauer<fnref n="2" />, T. Hutschenreuther<fnref n="3" />, H. Toepfer<fnref n="4" />, P. Dietrich<fnref n="1" />,<fnref n="5" />

To characterize environmental systems it is necessary to detect individual processes with suitable monitoring methods. Due to the natural heterogeneity of ecosystems, single point measurements are insufficient for an adequate representation. The application of mobile wireless sensor networks in terrestrial and aquatic ecosystems offer significant benefits, because of the simple adaption (e.g. sensor distribution, sensor types and sample rate) to the local test conditions. This can be essential for the monitoring of heterogeneous and dynamic environmental systems. A significant advantage in the application of mobile ad-hoc wireless sensor networks is their self-organizing behavior. In combination with the localization via satellite a major reduction in installation and operation costs and time is possible. In addition, a point measurement with a sensor is significantly improved by measuring at several points. It is also possible to perform analog and digital signal processing and computation in the sensor nodes close to the sensors. Hence, a significant reduction of the data to be transmitted can be achieved which leads to a better energy management of nodes. Furthermore the miniaturization of the nodes and energy harvesting are current topics under investigation. First results of field measurements are given to present the potentials and limitations of this application in environmental science, especially for the monitoring of the interaction of biotic and abiotic processes, soil atmosphere interaction and the validation of remote sensing data.

<footnote n="1">¹Helmholtz Centre for Environmental Research - UFZ, Department Monitoring and Exploration Technologies, Leipzig, Germany</footnote>

<footnote n="2">²TETRA Gesellschaft für Sensorik, Robotik und Automation mbH, Ilmenau, Germany</footnote>

<footnote n="3">³Institut für Mikroelektronik- und Mechatronik-Systeme - IMMS, Department of System Design, Ilmenau, Germany</footnote>

<footnote n="4">⁴Ilmenau University of Technology, Department of Advanced Electromagnetics, Ilmenau, Germany</footnote>

<footnote n="5">⁵Eberhard Karls University, Centre of Applied Geosciences, Tübingen, Germany</footnote>
A non-invasive microwave method using microstrip antennas to measure soil moisture in the profile of a rhizobox

P. S. de Paula Herrmann Jr<fnref n="1" />,<fnref n="2" />, V. Sydoruk<fnref n="3" />, C. Windt<fnref n="3" />, S. Jahnke<fnref n="3" />, F. Fiorani<fnref n="3" />, U. Schurr<fnref n="3" />, D. van Dusschoten<fnref n="3" />

New tools or approaches are considered important to investigate and evaluate soil-water-plant interactions in the plant phenotyping investigations (Fiorani; Schurr, 2013). A central parameter determining root system response to water availability is that water is usually not homogenously distributed in the soil and the heterogeneity significantly increases when drought stress occurs. Thus the development of non-invasive instruments and sensors to measure soil moisture distribution would open up new approaches to investigate plant strategies to deal with low water content or, in particular, heterogeneities in water availability of soils during periods of drought cycles.

To explore the use of scattering parameters (S-parameters) at microwave frequency range close to 5.0 GHz we developed a system with microstrip antennas, placed on both sides of a rhizobox, to non-invasively measure soil moisture in the box. The variation of water content profiles over time was monitored under laboratory conditions. Rhizoboxes are normally used to study root growth during plant development and can be applied in the investigation of critical zone impact on root performance.

The antenna was simply designed as a λ/2-resonant microstrip antenna (Cataldo et al, 2009) and realized on a circuit board with a thickness of 1.5 mm and a dielectric constant, ε<sub>r,sub</sub>, of 4.4. The antenna was 15.7 mm in width and 15.2 mm in length. A Vector Network Analyzer (ZNB 8, Rohde & Schwarz) was used to measure changes of the transferred high frequency parameter, S<sub>21</sub>, and the reflected high frequency parameters, S<sub>11</sub> and S<sub>22</sub>, with a resolution of 6 x 10<sup>-3</sup> dB. This was applied to measure non-invasively soil moisture in rhizoboxes made from Plexiglas and PVC. The boxes had a length of 315.0 mm, a width of 200.0 mm, about 5 mm thick walls and were filled with soil. There were two different sizes with an internal thickness of either 20 or 40 mm. The antennas were moved with steps of 5.0 mm every 4.0 s in the vertical direction (length) of the rhizoboxes. The distance between the microstrip antennas was 33.5 mm and 61.2 mm for the 20 mm and 40 mm thick rhizoboxes, respectively. We used a soil with an organic matter content of 19.1% for which a moisture calibration curve was obtained by measuring S<sub>21</sub>. Six samples of the soil were prepared differing in volumetric moisture content, Θ<sub>v</sub>(%), with 0.0%, 6.7%, 13.4%, 20.1%, 26.8% and 33.4%. The bulk densities (ρ<sub>b</sub>) of the soil samples were ρ<sub>b</sub> = 0.597 ±0.009 g/cm<sup>3</sup>. To investigate changes of water distribution in the soil, 40 ml of deionized water was spread uniformly on the top of dry soil of one rhizobox which was then scanned with microstrip antennas every 5 to 30 min over a time period of 2 days. The experiments were made in the laboratory conditions with a temperature of about 25°C and a relative humidity of approximately 30%.

The calibration curve of the soil moisture (S<sub>21</sub> vs Θ<sub>v</sub>(%)) for the thin rhizoboxes filled with 20 mm soil in thickness was obtained as:

$$ \Theta_v (\%) = -83.443 - 11.356 \times S_{21} - 0.277 \times S_{21}^2 \quad (R^2 = 0,9521) $$

<footnote n="1">¹FZJ/IBG-2 // Embrapa Labex Europe Germany, Plant Sciences, Jülich, Germany</footnote>

<footnote n="2">²Embrapa SRI, Brasilia-DF, BRAZIL, Germany</footnote>

<footnote n="3">³Forschungszentrum Jülich / IBG-2: Plant Sciences, Jülich, Germany</footnote>
<table><caption>Table 1. Measures of S₁₂ for pure water in the thin rhizobox and for soil in the differently sized rhizoboxes.</caption><thead><tr><th rowspan="2">Substrate</th><th colspan="2">Internal thickness of rhizobox</th></tr><tr><th>20 mm</th><th>40 mm</th></tr></thead><tbody><tr><td></td><td colspan="2">S<sub>12</sub> (dB)</td></tr><tr><td>Deionized water</td><td>- 26.369</td><td>---</td></tr><tr><td>Soil with p<sub>ds</sub> = 0.593 ±0.008 g/cm<sup>3</sup><br>and Θ<sub>V</sub> = 33.4%</td><td>-18.666</td><td>-35.231</td></tr></tbody></table>

With the measured temporal change in soil water profile it was possible to evaluate the permeability of the soil. At the beginning of the experiment, the volumetric soil moisture Θ<sub>V</sub>, at 40 mm below the top of the soil was 31,8% and at 110 mm it was 3,8%. After 2 days, Θ<sub>V</sub> was similar (3,6%) at both positions. At 40 mm the equation fitted to the data over time was a polynomial of 3rd order and, at 110 mm, the equation was just linear. Using the data from this experiment, the permeability was calculated as about 0.156 cm h<sup>-1</sup>. Refering to Soil Survey Staff, (1999) and Vogel, (2000) the permeability class of this sample can be considered slow.

From the measured results it is possible to conclude that the developed non-invasive microwave method, using microstrip antennas, is an innovative sensing method to measure the water status in rhizoboxes filled with soil. This can be used to investigate the growth of plant roots together with soil physics properties. Such kind of approach gives an opportunity to apply it to study the critical zone and to use it to monitor 2-D soil moisture distribution in rhizoboxes.

References:

Fiorani, F. ; Schurr, U. Future Scenarios for Plant Phenotyping, Annual Review of Plant Biology 64, 267 - 291, (2013).

Cataldo, A.; Monti, G.; De Benedetto, E.; Cannazza, G.; Tarricone, L. A noninvasive resonance-based method for moisture content evaluation through microstrip antennas, IEEE Transactions on Instrumentation and Measurement 58(5), 1420-1426, (2009),

Soil Survey Staff. Soil Taxonomy A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Agricultural Handbook No. 436. U.S. Government Printing Office Washington, DC, 1999.

Vogel, H. J. A numerical experiment on pore size, pore connectivity, water retention, permeability, and solute transport using network models. European Journal of Soil Science 51, 99-105, 2000.
Calibrating cosmic ray neutron sensors for soil moisture measurements in deciduous forests

I. Heidbüchel¹, T. Blume¹, A. Güntner¹

¹GFZ Potsdam, Hydrology, Potsdam, Germany

Cosmic ray neutron sensors are still a relatively new measurement technique to determine soil moisture at the intermediate scale (within a 300 m radius). Using them means moving from point measurements provided by individual soil moisture sensors towards larger footprints. The neutron sensors have to be calibrated once, therefore, in order to make them universally applicable it is indispensable to agree on a calibration procedure that yields consistent soil moisture values independent of the time of calibration. We repeated the calibration of a cosmic ray neutron sensor that was permanently installed in a deciduous forest eight times within one year. These calibrations included one winter calibration, five spring calibrations that covered the trees' leaf-out and two summer calibrations (one during relatively wet conditions and one during relatively dry conditions). We applied all the common corrections for air pressure, background neutron flux and humidity. For each of the calibrations we obtained slightly different count rates of cosmic ray neutrons over dry soil (N0, which is the calibration parameter). This resulted in 8 soil moisture time series with differences of over 10% in volumetric water content. We approached the problem of determining the correct N0 value from different angles: averaging count rates over longer time periods, accounting for changes in aboveground biomass, accounting for water in the higher atmosphere (clouds above 300 m). We also looked at the changing soil moisture patterns throughout the 8 calibration time periods and whether this variability had an influence on the calibration.
A new approach to investigate soil moisture dynamics by radio waves

O. Kiseleva<fnref n="1" />, C. Hübner<fnref n="2" />, A. Brandelik<fnref n="1" />, N. Kalthoff<fnref n="1" />, M. Kohler<fnref n="1" />, F. Königer<fnref n="3" />, C. Kottmeier<fnref n="1" />

The large scale mapping of soil properties, particularly of soil moisture is eminent for the estimation and management of water resources. There are various methods for soil moisture measurements, but none of them is able to provide continuous, integrated estimates of the soil moisture content over an area of typically 10-50 km and a depth of 1-2 m.

The principle of the new approach is based on the correlation between propagation characteristics of low frequency radio surface waves and soil moisture. The propagation of the wave depends on the electric conductivity of the media, which is beside others a function of the moisture content. Hence the resulting phase and amplitude changes of the surface wave, is a measure for the soil moisture content in the monitored area.

The radio signal used, is the DCF77-time signal from Mainflingen, Germany. Between Edingen, near Heidelberg and Karlsruhe in Southwest Germany, three stations are lined up at intervals of 20 km, to measure the phase transition of the surface wave. The GPS time signal is used as a reference for the phase transition. Nine soil moisture stations and the data of numerous ground water monitoring stations along the measurement section are used to calibrate and to evaluate the data.

The analysis of a two year period of measurements show a depicted dependence of the phase measurements on the soil moisture evolution in the monitored soil layer.

<footnote n="1">¹ Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research - Troposphere Research (IMK-TRO), Karlsruhe, Germany</footnote>

<footnote n="2">²TRUEBNER GmbH, Neustadt, Germany</footnote>

<footnote n="3">³Karlsruhe Institute of Technology (KIT), Institute of Functional Interfaces (IFG), Eggenstein-Leopoldshafen, Germany</footnote>
# Observation of soil moisture variability in agricultural and grassland field soils using a wireless sensor network

E. Priesack¹, M. Schuh¹

¹Institute of Soil Ecology, Helmholtz Center Munich, Oberschleissheim, Germany

Soil moisture dynamics is a key factor of energy and matter exchange between land surface and atmosphere. Therefore long-term observation of temporal and spatial soil moisture variability is important in studying impacts of climate change on terrestrial ecosystems and their possible feedbacks to the atmosphere. Within the framework of the network of terrestrial environmental observatories TERENO we installed at the research farm Scheyern in soils of two fields (of ca. 5 ha size each) the SoilNet wireless sensor network (Biogena et al. 2010). The SoilNet in Scheyern consists of 94 sensor units, 45 for the agricultural field site and 49 for the grassland site. Each sensor unit comprises 6 SPADE sensors, two sensors placed at the depths 10, 30 and 50 cm. The SPADE sensor (sceme.de GmbH, Horn-Bad Meinberg Germany) consists of a TDT sensor to estimate volumetric soil water content from soil electrical permittivity by sending an electromagnetic signal and measuring its propagation time, which depends on the soil dielectric properties and hence on soil water content. Additionally the SPADE sensor contains a temperature sensor (DS18B20).

First results obtained from the SoilNet measurements at both fields sites will be presented and discussed. The observed high temporal and spatial variability will be analysed and related to agricultural management and basic soil properties (bulk density, soil texture, organic matter content and soil hydraulic characteristics).
# Soil moisture and shallow groundwater monitoring at the pre-Alpine TERENO site
## Peißenberg-Fendt

B. Fersch<fnref n="1" />, T. Rödiger<fnref n="2" />, R. Krieg<fnref n="2" />, H. Kunstmann<fnref n="1" />, R. Merz<fnref n="2" />

The TERENO initiative aims at the detection of environmental changes at the regional level. In this context, the influence of climate on water resources depicts an important question.

Near surface soil moisture states and shallow groundwater dynamics are a major regulator for the vertical exchange of water and energy between the land-surface and the atmospheric boundary layer. Due to the spatio-temporal heterogeneity of subsurface moisture transport and surface partitioning, it is difficult to obtain representative observations that qualify for an evaluation with physically-based, distributed complex hydrometeorological models. Moreover, to enable also spatial applicability at the respective model scales, the local observations need to be related to remotely sensed data.

In order to increase process understanding and to provide multi-scale observations of soil-moisture, the pre-Alpine critical zone grassland observatory at Peißenberg-Fendt, Southern Germany will be equipped with a wireless soil-moisture sensing network. Hydraulic head measurements are carried out for the shallow saturated zone and for the deeper main aquifer. The interrelation between surface and sub-surface compartments is studied through stable isotope and hydrochemical analysis. A cosmic ray soil moisture observation probe, with a horizontal footprint of several hundreds of meters, will be used to bridge between small scale variability and model resolution. Moreover, observations from satellite and air-borne remote sensing become comparable and scaling issues can be addressed. The on-site eddy-covariance and climate station provide the observational link to the atmospheric boundary exchange. With this overarching observational setup, cross-compartment hydrometeorological model studies can be conducted, thereby overcoming temporal and spatial scales.

<footnote n="1">¹Karlsruhe Institute of Technology, IMK-IFU, Garmisch-Partenkirchen, Germany</footnote>

<footnote n="2">²Helmholtz-Centre for Environmental Research - UFZ, Department Catchment Hydrology, Halle, Saale, Germany</footnote>
# Surface ground penetrating radar full-waveform inversion to characterize soil texture and soil water content at the Selhausen test site

A. Klotzsche¹, S. Busch¹, J. van der Kruk¹, H. Vereecken¹

¹Forschungszentrum Jülich GmbH, Agrosphere IBG-3, Jülich, Germany

Ground penetrating radar (GPR) measurements can be performed quickly and effectively to map electromagnetic properties to characterize the subsurface at the field-scale and can be applied to a wide range of applications such as geophysical engineering, environmental studies, infrastructure characterization and agricultural engineering. The method provides two subsurface properties: the dielectric permittivity and electrical conductivity. The permittivity is highly correlated with soil water content and porosity, whereas the conductivity depends on soil properties such as ion concentration, soil texture and clay content. Therefore, GPR is well suited to characterize and to improve our understanding of dynamic processes that are taking place in the soil. Permittivity and conductivity can be obtained from common midpoint (CMP) or wide-angle reflection-refraction (WARR) measurements. The permittivity is commonly estimated by applying ray-based techniques such as ground-wave travel-time picking, whereas the conductivity can be estimated by fitting far-field amplitude decay functions to the picked first-cycle amplitudes. Nevertheless, these methods can contain errors because only small parts of the information present in the GPR data are considered and simplified models are used. In contrary, full-waveform inversion of GPR data uses significant parts of the wave field and is able to provide a reliable and quantitative estimate of the permittivity and the conductivity. The method uses an exact forward model based on a 3D frequency domain solution of Maxwell's equation and assumes a layered earth model, whereas a sequential optimization is performed of the effective source wavelet and the subsurface parameters.

Here, we employed this surface full-waveform inversion to characterize the TERENO test site Selhausen that is located close to Juelich in the Lower Rhine Embayment, Germany. The soil type of the test site consists of silty loam with a transition from coarse to fine textured soils from east to west. The field campaign in 2012 was performed along a 120m long transect and included GPR WARRs. GPR profiles, EMI measurements, theta probes and soil sampling. The WARR GPR data was acquired every 5 m using a 200 MHz antenna and an antenna step size of 0.05m. The WARR data is inverted using the full-waveform inversion and is able to provide permittivity and conductivity values, whereas the GPR profiling is able to map stratigraphy and lateral changes in the near surface. The inverted permittivity results are transformed into soil water content using the 4-phase CRIM model and compared to soil samples and Theta probe measurements that are available for every 10 m and 5 m, respectively, whereas the obtained full-waveform conductivity results are compared with inverted large-scale EMI data.
# Predicting the variability of soil water content using unsaturated flow stochastic analysis and pedotransfer function

W. Qu<fnref n="1" />, H. R. Bogena<fnref n="1" />, J. A. Huismann<fnref n="1" />, M. Schuh<fnref n="2" />, E. Priesack<fnref n="2" />, H. Vereecken<fnref n="1" />

Understanding the variability of soil water content ($\sigma_\theta$) and the relationship with its mean ($<\theta>$) plays an important role in hydrological research. Such $\sigma_\theta(<\theta>$) behavior can be considered as a fundamental property of a heterogeneous soil, which is related to the spatial variability in soil water retention characteristic. The existing stochastic models of unsaturated flow are based on the simple Gardner-Russo or Brooks-Corey constitutive relationship. In this study we developed the stochastic model with the more complex van Genuchten-Mualem model of steady state, gravity dominated unsaturated flow. The stochastic model was expressed as a closed form between $\sigma_\theta$ and the van Mualem Genuchten (VGM) parameters. A sensitivity analysis was performed to identify the effect of VGM parameters on the shape of the $\sigma_\theta(<\theta>$) curve. We found that the n parameter strongly influenced the shape of the $\sigma_\theta(<\theta>$) curve and specifically the occurrence of the maximum. The closed form equation was combined with the PTFs from Rosetta to estimate $\sigma_\theta(<\theta>$) curve for seven different locations with varying textural composition. Five out of seven locations showed a very good agreement between observed and predicted $\sigma_\theta(<\theta>$) curve. We demonstrate that the closed form expression can be used to derive the soil hydraulic properties and their variability from field measured $\sigma_\theta(<\theta>$) curve. These results give us an important insight in the interpretation of observed soil water content variability in the field and potentially lead to a better understanding and a more fundamental interpretation of the soil water variability in land surface processes across scales.

<footnote n="1">¹Forschungszentrum Jülich GmbH, Jülich, Germany</footnote>

<footnote n="2">²Institute of Soil Ecology Helmholtz Center München, Neuherberg, Germany</footnote>
# Field-scale prediction of soil moisture patterns by means of a fuzzy c-means clustering algorithm, digital elevation data, and sparse TDR measurements

I. Schröter¹, H. Paasche¹, P. Dietrich¹, U. Wollschläger¹

¹UFZ, Monitoring and Exploration Technologies, Leipzig, Germany

Soil moisture is a key variable of the hydrological cycle. For example, it controls partitioning of rainfall into a runoff and an infiltration component and modulating physical, chemical and biological processes within the soil. For a better understanding of these processes, knowledge about the spatio-temporal distribution of soil moisture is indispensable. For the field to the small catchment scale with survey areas up to a few square kilometres, there are numerous new and innovative ground-based and remote sensing technologies available which have great potential to provide temporal information about soil moisture patterns.

The aim of this work is to design an optimal soil moisture monitoring program for a low-mountain catchment in central Germany. In a first step, the fuzzy c-means clustering technique (Paasche et al., 2006) was used to identify structure-relevant patterns in a set of different terrain attributes derived from a DEM. Based on these patterns optimal measurement locations were identified to conduct in-situ soil moisture measurements. To consider different wetting and drying states in the catchment, several TDR measurement campaigns were conducted from April to October 2013. The TDR measurements have been integrated with the structure-relevant patterns obtained by the fuzzy cluster analysis to regionally predict soil moisture. In this study, we outline the conceptual framework of this integrative approach and present first results from field measurements.

The results of the project are expected to improve the monitoring and understanding of small catchment-scale hydrological processes and to contribute to a better representation of soil moisture dynamics in physically-based, hydrological models operating at the field to the small catchment scale.

## Reference:

Paasche, H., J. Tronicke, K. Holliger, A.G. Green, and H. Maurer (2006): Integration of diverse physical-property models: Subsurface zonation and petrophysical parameter estimation based on fuzzy c-means cluster analyses. Geophysics 71(3), H33-H44, doi:10.1190/1.2192927.
# Integrating data assimilation techniques and Passive Distributed Temperature Sensing for high resolution soil moisture measurements

J. Dong¹, S. Steele-Dunne¹, N. van de Giesen¹

¹Delft University of Technology, Water resource management, Delft, Netherlands

Soil moisture plays a pivot role in hydrology and water resources management. For many hydrological applications, the resolution of remote sensing data is too coarse. To maximize the use of remote sensing data products, it is essential that we can account for spatial variability within the footprint. This involves using measurement techniques to bridge the observation gap from traditional point scale in-situ measurements to footprint-scale measurements from remote sensing. Distributed temperature sensing (DTS) is an innovative tool for high resolution temperature measurements (spatial < 1m, and temporal < 1min) along fiber optic cables which can extend up to kilometers in length. Previous studies demonstrated the feasibility of using DTS to measure soil moisture using active and passive DTS. The Active DTS method involves providing a heat pulse to the cable, and inferring soil moisture from the temperature change in the cable during and after the pulse. Passive DTS uses measured soil temperature at multiple depths, and estimates soil thermal property by inverting the soil heat transfer equation. Finally, moisture is estimated using the relationship between soil moisture and thermal diffusivity. Compared with Active DTS, Passive DTS requires no artificial energy input, which is preferable in field implementations. However, Passive DTS is affected by many sources of uncertainty, and can be difficult when solar radiation is low. Here we will present results from a new approach to soil moisture estimation using Passive DTS. We compare results from different data assimilation approaches used to combine temperature observations from Passive DTS with a physical model of the soil column. This gives us a unique perspective on the potential value of the passive DTS data. We will use synthetic experiments to illustrate the sensitivity to different sources of uncertainty and error.
Parameter and state estimation for catchment scale carbon flux simulations with the
Community Land Model (CLM)

H. Post<fnref n="1" />, T. Hoar<fnref n="2" />, J. A. Vrugt<fnref n="3" />, X. Han<fnref n="1" />, A. Fox<fnref n="4" />, R. Baatz<fnref n="1" />, P. Kumbhar<fnref n="5" />, H. Vereecken<fnref n="1" />, H.-J. Hendricks Franssen<fnref n="1" />

Until now the land surface model CLM was mainly applied for global scale simulations without detailed consideration of within-catchment variability of carbon fluxes. However, the information gained from small scale (high resolution) CLM simulations is valuable e.g. in terms of understanding the interactions of carbon fluxes and hydrology within a catchment. We used CLM version 4.5 (CLM4.5) at 1 km<fnref n="2" /> resolution to simulate the net ecosystem exchange of CO₂ (NEE) for the 2454 km<fnref n="2" /> Rur catchment located in the border region of Belgium, Germany, and the Netherlands. After an initial sensitivity analysis, eight key parameters controlling the carbon uptake and respiration in CLM were calibrated against observed data to mimic as accurately and consistently as possible the observed variations in NEE. Parameter estimation was performed for individual grid-cells using DREAM(ZS), an adaptive Markov Chain Monte Carlo (MCMC) method (Laloy and Vrugt, 2012; Ter Braak and Vrugt, 2008). The data used for calibration consist of NEE time series measured by eddy covariance towers at different sites within the Rur catchment. To improve the consistency of modeled and measured NEE, CLM state variables were estimated using an Ensemble Kalman Filter with the Data Assimilation Research Testbed (DART) (Anderson et al., 2009). With DART-CLM we assimilated remotely sensed leaf area index from the Moderate Resolution Imaging Spectroradiometer in addition to NEE and latent heat flux observations.

References:

Anderson, J., Hoar, T., Raeder, K., Liu, H., Collins, N., Torn, R., Avellano, A., 2009. The data assimilation research testbed: A community facility. Bull. Am. Meteorol. Soc. 90, 1283-1296.

Laloy, E., Vrugt, J.A., 2012. High-dimensional posterior exploration of hydrologic models using multiple-try DREAM(ZS) and high-performance computing. Water Resour. Res. 48, 1-18.

Ter Braak, C.J.F., Vrugt, J.A., 2008. Differential Evolution Markov Chain with snooker updater and fewer chains. Stat. Comput. 18, 435-446.

<footnote n="1">¹Forschungszentrum Jülich GmbH, IBG3-Agrosphere, Jülich, Germany</footnote>

<footnote n="2">²National Center for Atmospheric Research, Boulder, Germany</footnote>

<footnote n="3">³University of California, Department of Civil and Environmental Engineering, Irvine, United States</footnote>

<footnote n="4">⁴National Ecological Observatory Network, Boulder, United States</footnote>

<footnote n="5">⁵École polytechnique fédérale de Lausanne, Lausanne, Switzerland</footnote>
# Testing of four data assimilation algorithms including parameter estimation at the TERENO-site Rollesbroich

H. ZHANG¹, H.-J. Hendricks-Franssen¹, H. Vereecken¹

¹Forschungszentrum Jülich, Agrosphere (IBG-3), Jülich, Germany

Ensemble Kalman Filtering (EnKF) and Particle Filtering (PF) are two popular data assimilation methods, which are both based on the Monte Carlo approach. In this work, the performances of two variants of each method were investigated. Two approaches of joint estimation of states and parameters in EnKF are compared: state augmentation and dual estimation. In the state augmentation approach, the state and parameter vector are combined into a single joint state vector and the states and parameters are estimated simultaneously. In the dual estimation approach, states and parameters are stored in two vectors. Parameters are updated first and then the updated parameters are used to update states. For the particle filter we tested the sequential importance resampling Particle Filter (SIR-PF) and the Markov chain Monte Carlo particle filter (McMC-PF). In McMC-PF, after resampling, a move step is added on particles, creating a proposal distribution. A Metropolis ratio is calculated to judge whether the proposal particle is accepted or not. If the proposal particle is accepted, it replaces the corresponding particle. The PF estimates states and parameters in the same step. When particles are resampled, the parameters generating the particles are also resampled.

The four different algorithms were tested for the TERENO-site Rollesbroich, assimilating measured soil moisture data at 5, 20 and 50cm depth measured by SoilNet during a period of six months. The next six months served as verification period. The assimilation experiments were carried out with the Variable Infiltration Capacity (VIC) model. We considered uncertainty with respect to soil hydraulic parameters, meteorological forcings and model structural error. Results showed that all data assimilation algorithms resulted in better predictions for the verification period if parameters were updated. However, nearly all algorithms were not able to significantly improve soil moisture predictions at 50cm, which was related to the parameterization of groundwater drainage in VIC.
# Monitor Water and Energy Fluxes by Jointly Assimilation of Land Surface Temperature and Soil Moisture

T. Xu¹, S. Liu¹, Z. Xu¹

¹Beijing Normal University, Beijing, China

Water and energy fluxes are the sensible and latent heat fluxes between the land surface and atmosphere boundary layer. Accurate estimation of water and energy fluxes is very important in many fields such as meteorology, hydrology and agronomy. Data assimilation is a new method that can integrate observation data from different sources with models, and produce accurate land surface states. Therefore, a large number of data assimilation scheme has been developed to estimate land surface states including water and energy fluxes. Land surface model is the principle part of a land data assimilation scheme, and can produce land surface states continuously. Water and energy fluxes are diagnostic variables in land surface models, and the estimate accuracy is affected by model uncertainties from the parameterization scheme, soil and vegetation parameters, model states, and forcing data. With data assimilation technique, the observations are used to reduce uncertainties of land surface model. Recently, the observations from multiple platforms and the developed data assimilation techniques promoted the evolution in improving predictions water and energy fluxes. The soil moisture and LST are both important to water and energy fluxes and cannot replace role of each other. But by now, there is no efficient way to improve water and energy fluxes by jointly assimilating both of them. The aim of this study is to develop a data assimilation scheme that can efficiently improve predictions of water and energy fluxes with the assimilation of both soil moisture and LST observations.

HiWATER (Heihe Watershed Allied Telemetry Experimental Research) was initialized in 2012 and will last four years until 2015, which include airborne mission plans, flux observing matrix, eco-hydrological wireless sensor network, and so on. HiWATER can provide adequate data (in-situ measurements and airborne remote sensing data) to do the data assimilation experiments and improve model performances. The HiWATER dataset of in-situ measurements (meteorology, leaf area index, soil texture data, and eddy covariance data, etc.) and satellite data (land surface temperature and leaf area index from MODIS, soil moisture from SMOS) are used in the data assimilation experiment.

In this study, the jointly data assimilation experiments are conducted at two different temporal and spatial scales with the in-situ measurements (with high temporal resolution and small spatial scale, soil moisture data from cosmic-ray and LST from radiometer) and with remote sensing data (with low temporal resolution and large spatial scale, SMOS soil moisture and MODIS LST products). The assimilation results of water and energy fluxes are compared with eddy covariance measurements. And the results show well agreement with the in-situ measurements.
# An improved characterization of riverbed heterogeneities and river-aquifer exchange fluxes with the normal score ensemble Kalman filter

Q. Tang<sup>1,2</sup>, W. Kurtz<sup>1,2</sup>, H. Vereecken<sup>1,2</sup>, H.-J. Hendricks Franssen<sup>1,2</sup>

Interactions between surface water and groundwater play an essential role in hydrology, hydrogeology, ecology, and water resources management. A proper characterization of riverbed structures is important for estimating river-aquifer exchange fluxes. The ensemble Kalman filter (EnKF) is commonly used in subsurface flow and transport modeling for estimating states and parameters. However, EnKF only performs optimally for multi-Gaussian distributed parameter fields, but the spatial distribution of streambed hydraulic conductivities often shows non-Gaussian patterns which are related to flow velocity dependent sedimentation and erosion processes. In this study, we assumed a riverbed with non-multi-Gaussian distributed hydraulic parameters as a virtual reference. The synthetic study was carried out for a 3-D river-aquifer model with a river (conceptualized as a flow domain with eight lines consisting of each out of 51 river nodes) in the middle of a homogeneous aquifer. Next, in a series of data assimilation experiments two different scenarios were studied. In the first scenario stochastic realizations of non-multi-Gaussian riverbeds were inversely conditioned to state information, using EnKF and the normal score ensemble Kalman filter (NS-EnKF), which honors the non-Gaussian distribution of states and parameters. NS-EnKF builds a normal-score transformation of states and parameters, updates these normal-score transformed states and parameters and then back-transforms the scores. In the second scenario, the stochastic realizations of riverbeds have multi-Gaussian distributed hydraulic parameters and are conditioned to state information with EnKF. It was found that better results were achieved for non-multi-Gaussian stochastic realizations, especially for the characterization of river-aquifer exchange fluxes. In addition, it was concluded that both EnKF and NS-EnKF improve the characterization of non-multi-Gaussian riverbed properties, hydraulic heads and exchange fluxes with assimilation of piezometric heads. NS-EnKF outperforms EnKF when only parameters are normal-score transformed but states are not transformed.

<footnote n="1"><sup>1</sup>Forschungszentrum Jülich, IBG-3, Jülich, Germany</footnote>

<footnote n="2"><sup>2</sup>Centre for High-Performance Scientific Computing in Terrestrial Systems, HPSC TerrSys, Geoverbund ABC/J, Jülich, Germany</footnote>
# Assimilation of cosmic-ray soil moisture observations into an integrated land surface-subsurface model

W. Kurtz<sup>1,2</sup>, H.-J. Hendricks Franssen<sup>1,2</sup>, G. He<sup>1,2</sup>, P. Shrestha<sup>3</sup>, M. Sulis<sup>3</sup>, S. Kollet<sup>1,2,3</sup>, H. Vereecken<sup>1,2</sup>

The coupling of land surface and subsurface models might improve the overall predictive accuracy of hydrological and atmospheric models. In general, predictions with such highly parameterized models are associated with a considerable degree of uncertainty due to the uncertain initial conditions and the poorly known subsurface and vegetation properties. An important variable of such systems is the soil moisture content which influences the partitioning of energy fluxes at the land surface and is highly variable in space and time. Information on soil moisture content is therefore essential for improving the prediction capability of integrated models, e.g., with respect to the estimation of latent and sensible heat fluxes from the land surface, regional water budgets and river discharge, and for constraining the associated uncertainties of these variables. Soil moisture data can be derived from a variety of sensor types which operate at different spatial scales ranging from point measurements like TDR sensors (dm scale) over medium range measurements like cosmic ray probes (ha scale) to large scale measurements like satellite remote sensing products (km scale). Especially cosmic ray soil moisture data are well suited for medium scale distributed hydrological models because their footprint closely matches the typical spatial discretization of such models. We will present first results on the assimilation of cosmic ray soil moisture data into an integrated hydrological model of the Rur catchment (Germany). The integrated model consists of the land surface model CLM and the groundwater model Parflow which are coupled via state and flux variables by the coupling software Oasis-MCT. Soil moisture data for assimilation are available from 10 cosmic ray stations which are distributed over the whole catchment area. These data are assimilated into the subsurface model (Parflow) with the Ensemble Kalman Filter and the value of this assimilation is monitored through cross validation with surface flux measurements and discharge data.

<footnote n="1"><sup>1</sup>Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences: IBG-3 (Agrosphere), Jülich, Germany</footnote>

<footnote n="2"><sup>2</sup>Forschungszentrum Jülich GmbH, Centre for High-Performance Scientific Computing in Terrestrial Systems (HPSC TerrSys), Jülich, Germany</footnote>

<footnote n="3"><sup>3</sup>University of Bonn, Meteorological Institute, Bonn, Germany</footnote>
# The development of water balance components under different groundwater regimes on sites with shallow water tables

O. Dietrich<fnref n="1" />, M. Fahle<fnref n="1" />, T. Kaiser<fnref n="2" />, M. Wegehenkel<fnref n="3" />

Sites with shallow groundwater tables constitute a great proportion of German lowlands. These sites can be natural wetlands or unused nature protection areas. But most commonly in Germany and Middle Europe, they are drained and used for agriculture or forestry. Few decimetres higher or deeper water levels decide on the vegetation development and determine the fate of peatlands, i.e. if they grow or degrade. Therefore these sites are often in the centre of conflicts between different interest groups, especially between farmers and conservationists. The understanding of the complex water balance of sites with shallow groundwater tables, including knowledge of the effects that different water regimes exert on the water budget, is a precondition to find compromises acceptable for both groups.

Nature protection groups ask for higher water levels in winter and spring, especially in regions that receive few precipitations but have a high evapotranspiration demand during the summer months. The measure is believed to slow down the water level lowering in spring and early summer, leading to higher groundwater levels during the summer months and therefore limiting the need for sub-irrigation during that time. However, the farmers are concerned that the measure may cause a higher overall water demand and decrease the yield as well as the forage quality of the growing grass.

To quantify the effect of different groundwater regimes on the water balance components, we conducted experiments with weighable groundwater lysimeters. The lysimeters are situated in the Spreewald wetland, amid an extensive used grassland site. A special system for automatic control of the lysimeters was developed and applied to enable a realistic simulation of the different groundwater regimes. Between 2012 and 2014 the impact of different groundwater levels on evapotranspiration and the groundwater development was investigated during spring. Three variants were tested. The basic variant (variant 1) simulated the groundwater level of the surrounding area. For the other two variants the groundwater levels were set few centimetres below the surface (variant 2) and few centimetres above the surface (variant 3) at the starting point of the investigations in April. Afterwards the groundwater levels could freely develop and all variants were compared with each other.

The results show that the water balance components of the three variants behaved differently. The variants with higher groundwater levels showed a higher demand for evapotranspiration, partly caused by their vegetation which adapted better to the wetland conditions. In 2012 and 2013 the values of the variant 3 were 40% higher than those of the basic variant. The additional evaporated water originated mainly from the higher water storage. No additional water was withdrawn from the aquifer, which in the Spreewald wetland is supplied by the streams and channels. The values of variant 2 lay in between both variants.

The groundwater levels of the variants 2 and 3 developed differently. For variant 2, they dropped down relatively fast. After reaching the level of the basic variant, both variants showed nearly the same behaviour. In contrast, the groundwater level of variant 3 decreased very slowly as long as it was above the surface, resulting from the higher specific water storage. As soon as the water level dropped below surface, it decreased very fast and reached the level of the other variants in few days.

We conclude that higher groundwater levels in spring and the joined higher water storage can compensate the higher evapotranspiration for some weeks. However, due to its time-limited effect, the measure is not sufficient to stabilize the water balance in the most critical phases in July and August.

<footnote n="1">¹Leibniz Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Landscape Hydrology, Müncheberg, Guatemala</footnote>

<footnote n="2">²Leibniz Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Land Use Systems, Müncheberg, Germany</footnote>

<footnote n="3">³Leibniz Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Landscape Systems Analysis, Müncheberg, Germany</footnote>
# A lysimeter study to assess the evolution and the environmental impact of excavated clay materials

P.- O. Redon<fnref n="1" />, A. Bossy<fnref n="1" />,<fnref n="2" />, G. Echevarria<fnref n="3" />, C. Leyval<fnref n="4" />, M. Buès<fnref n="5" />, N. Raoult<fnref n="6" />, M.- O. Simonnot<fnref n="2" />

Research on a suitable geological formation for long term disposal of nuclear waste has led to the construction of a deep underground research laboratory in easter France. The target formation, the Callovo-Oxfordian argillite, is a stable and homogeneous clay rock with very low permeability situated between 400-600m depth. The development of the laboratory has generated in the last 15 years a large amount of excavated material. In this study we are investigating the behaviour through time of the excavated material from the Callovo-Oxfordian formation when exposed to surface conditions. In the oxidising conditions prevailing in surface environment, complex alteration processes are known to affect the mineralogy and/or the organic matter associated with the clay. Characterising the extent of these changes and their potential impact on the quality of the environment is important to help define the repository conditions of the specific excavated material. The changing climatic conditions and the biological activities may by instance induce a release of saline elements and/or trace metals due to the alteration of the bearing phases, like pyrites.

Within the framework of the Long-term Environmental Observatory (OPE - Observatoire pérenne de l'environnement - www.andra.fr/ope) of the French Agency for Nuclear Waste Management (Andra), a lysimeter station was installed to specifically study the water flows in the excavated material and the chemical composition of the leaching water. Taking advantage of more than 10 years of research on the underground laboratory, lysimeters were filled with 10 years old and recently excavated clay material and with a natural soil developed on Callovo-Oxfordian bedrock. Several sensors were placed in each lysimeter at 20, 50, 100, 150cm depth to measure continuously the water content and the temperature in the clay material as well as the volume of leaching water. Regular water samples were collected to measure the anions and cations concentrations at different depths in each lysimeter. This experiment is allowing us to follow the changes of the chemical composition of the water interacting with either old or recent clay through time. These can be compared to the measurements in the natural soil that correspond to the future evolution of the excavated material after a long period of pedogenesis. Hydrological flux model combined with the characterization of the speciation in solution will be used in fine to determine the potential amount of chemical species released in leaching water over several decades of disposal.

The preliminary results of the study highlight a release of ionic species inherited from the marine origin of the clay rock. Large amounts of sulfates (up to 5 g.L⁻<fnref n="1" />), sodium, calcium, magnesium and potassium (1 to 600 mg.L⁻<fnref n="1" />) were measured in the collected water samples, while chloride and nitrate were found in lower concentrations (< 25 mg.L⁻<fnref n="1" />). The increasing water conductivity with depth in both old and recently excavated clay suggests a relatively fast leaching of these elements throughout the lysimeter column. However, low concentrations of metallic elements (Al, Mn, Ni, Co, Zn) were measured, and As, Cd, Cu, Cr, Pb, Sb were not detected which imply that the release of these potentially toxic elements due to mineral alteration is buffered by the alkaline pH of the water circulating within the argillite (pH 7.5 - 8.0). The lysimeter survey will be run for at least 10 years to provide more consistent results on the physico-chemical evolution of the clay. It will be complemented by lab based experiments (e.g. batch and columns), field works (runoff water measurements, revegetation...) and mineralogical analyses (XRD, microscopy, XAS...) to achieve a better understanding of the alteration processes occurring in the excavated clay material.

<footnote n="1">¹Andra, R&D, Bure, France</footnote>

<footnote n="2">²LRGP, Université de Lorraine-CNRS, Nancy, France</footnote>

<footnote n="3">³LSE, Université de Lorraine-INRA, Vandoeuvre-les-Nancy, France</footnote>

<footnote n="4">⁴LIEC, Université de Lorraine-CNRS, Vandoeuvre-les-Nancy, France</footnote>

<footnote n="5">⁵GeoRessources, Université de Lorraine-CNRS-ENSG, Vandoeuvre-les-Nancy, France</footnote>

<footnote n="6">⁶Gisfi, ENSAIA, Vandoeuvre-les-Nancy, France</footnote>
# Soil water dynamics inside and outside of small-scale lysimeters in extreme conditions

N. Obojes¹, G. Leitinger², G. Niedrist¹, G. Frenck², E. Tasser¹, U. Tappeiner¹,²

¹Eurac.research, Institute for Alpine Environment, Bolzano, Austria

²University of Innsbruck, Institute of Ecology, Innsbruck, Austria

While lysimeters allow the direct measurement of water fluxes through the soil-vegetation system, the realistic representation of natural soil water conditions is always a critical aspect in lysimeter research. The risk of deviations from the conditions of the undisturbed soil compartment increases for smaller lysimeters and in extreme conditions. As part of a study aimed to investigate the effects of spring and summer droughts on the productivity and water balance of an irrigated mountain grassland in the Vinschgau/Val Venosta region in northern Italy, we measured the soil water characteristics inside and outside of three small-scale lysimeters. Inside the lysimeters soil water content and matrix potential were measured at 5 and 20 cm depth. The lower boundary condition at 30 cm depth was adjusted to outside conditions measured with a tensiometer using a vacuum pump which allowed the removal but not the addition of water through a ceramic plate at the bottom of the lysimeter. Outside the lysimeters soil water content and matrix potential were measured at 5, 20 and 30 cm depth in six profiles with increasing distance to the lysimeters. The measurements were taken during the 2013 growing season which included experimental drought periods induced with foil tunnels from mid-April to mid-June and from end of July to beginning of September but also periods with natural precipitation as well as three irrigation events of 40 to 50 mm within four to six hours. Here we will present the effects of excluding capillary rise and lateral water flow on the soil water dynamics in small lysimeters in very dry conditions as well as during intense precipitation/irrigation. Our results will provide insights on the limitations of lysimeter studies and hints on how to improve the design of small lysimeters.
# ClimGrass - An experiment to quantify and understand effects of warming, elevated CO₂ and summer drought on productivity and biogeochemical processes in permanent grassland

M. Herndl<fnref n="1" />, E. M. Pötsch<fnref n="1" />, J. W. White<fnref n="2" />, B. Kimball<fnref n="2" />, H. P. Piepho<fnref n="3" />, M. Bahn<fnref n="4" />, A. Schaumberger<fnref n="1" />

Climate change is expected to occur at a rapid pace during the coming decades, involving a doubling of atmospheric CO₂ concentration, a warming by 3°C or more, and an increase in the frequency and severity of extreme climatic events. The Alpine region has experienced above average warming over the last century and is considered particularly vulnerable to global change. While there is already considerable knowledge on the responses of plants and ecosystems to individual climate factors, the combined and interactive effects of multiple climate drivers on ecosystem processes in real world ecosystems are much less known. ClimGrass is a multifactorial experimental approach testing effects of multiple levels of air temperature (ambient, +1.5°, +3°C), atmospheric CO₂ concentrations (ambient, +150, +300 ppm) and extreme summer drought on a managed grassland at AREC Raumberg-Gumpenstein in the Austrian Alps. Such managed grasslands are a highly relevant land cover type in many parts of Austria and other European mountain regions. In addition to 32 plots (4x4m with a core zone of 3 m<fnref n="2" />) arranged in a response surface design for warming and elevated CO₂ and an additional factorial design for testing effects of extreme summer drought, six large lysimeters will be exposed to key combinations of warming and elevated CO₂ to obtain high resolution information water and nutrient fluxes under future climate conditions. In addition, 48 grassland monoliths (30 cm diameter, 60 cm depth) will permit a testing of how altered fertilizer regimes modify ecosystem responses to climate change. This presentation will outline the experimental setup and testing of the unique ClimGrass facility and its potential as an experimental platform for testing complex climate interactions on the productivity and biogeochemistry of managed grassland.

<footnote n="1">¹AREC Raumberg-Gumpenstein, Irdning, Austria</footnote>

<footnote n="2">²USDA-ARS, Maricopa, United States</footnote>

<footnote n="3">³University of Hohenheim, Stuttgart, Germany</footnote>

<footnote n="4">⁴University of Innsbruck, Innsbruck, Austria</footnote>
# Towards an approach to validate filter methods to separate precipitation signal from noise in high frequency weighing lysimeter data

J. Groh¹, T. Pütz¹, J. Vanderborght¹, H. Vereecken¹

¹Forschungszentrum Jülich GmbH, Agrosphere (IBG-3), Jülich, Germany

High precision weighing lysimeter allow a more reliable water flux estimation across the upper- and lower boundary of soils [1]. In recent years, much work has been done on lysimeter design [2, 3] and on the processing of lysimeter weight records affected by noise [4-9]. Noise prone measurements prevent a direct estimation of water fluxes from lysimeter weight changes as each small increase or decrease of weight change will be interpreted as precipitation or evapotranspiration. Therefore the estimation of precipitation and evapotranspiration from high resolution lysimeter data depends on the appropriate use and functionality of the noise reduction method (filter-algorithm). However it is still unclear how to validate the procedure of individual state of the art filter-algorithms [10] on lysimeter observations, as long as noise affect the change of the lysimeter weight. The lack of a known noise free reference water flux on the upper lysimeter boundary (e.g. precipitation) makes it impossible to validate and to compare the impact of different filter-algorithms on the estimation of precipitation or evapotranspiration from lysimeter measurements.

In order to define the impact of different filter-algorithms on the separation of water exchange between the soil-plant-atmosphere continuums, we will present an experimental lysimeter set-up with a predefined upper boundary condition for several precipitation events. Within our experimental approach, we will apply a known input "precipitation" signal from a permanently weighted (high resolution 1 g) water reservoir on the lysimeter upper boundary. The lysimeter surface will be covered to omit weight changes due to evaporation or transpiration processes and the irrigation water will be collected in a tank which will be installed on the top of the lysimeter. Three different irrigation events which can be distinguished by its irrigation intensity will be used to measure parallel the noise free (irrigation) and the noise affected weight change of precipitation on the lysimeter.

The experimental set-up enables us to validate the performance of different state of the art filter-algorithms by a comparison of the derived goodness of fit between the observed (irrigation) and processed precipitation (filter-algorithms) data's.

1. Fank, J. and G. Unold, *High-precision weighable field Lysimeter - a tool to measure water and solute balance parameters*. International Water & Irrigation, 2007. **27**(3): p. 28.

2. Unold, G. and J. Fank, *Modular Design of Field Lysimeters for Specific Application Needs*. Water, Air, & Soil Pollution: Focus, 2008. **8**(2): p. 233-242.

3. Meissner, R., et al., *Measurement of dew, fog, and rime with a high-precision gravitation lysimeter*. Journal of Plant Nutrition and Soil Science, 2007. **170**(3): p. 335-344.

4. Nolz, R., G. Kammerer, and P. Cepuder, *Interpretation of lysimeter weighing data affected by wind*. Journal of Plant Nutrition and Soil Science, 2013. **176**(2): p. 200-208.

5. Schrader, F., et al., *Estimating Precipitation and Actual Evapotranspiration from Precision Lysimeter Measurements*. Procedia Environmental Sciences, 2013. **19**(0): p. 543-552.

6. Gebler, S., et al., *Simultaneous estimation of actual evapotranspiration and precipitation by weighable lysimeters and comparison with eddy covariance and rain gauge measurements*. 15. Gumpensteiner Lysimetertagung 2013, 2013: p. 199 - 202.

7. Vaughan, P. and J. Ayars, *Noise Reduction Methods for Weighing Lysimeters*. Journal of Irrigation and Drainage Engineering, 2009. **135**(2): p. 235-240.
8. Hannes, M., et al., *High-resolution estimation of the water balance of high-precision lysimeters*, in *EGU 2014. 2014, Geophysical Research Abstracts: Vienna*.

9. Peters, A., et al., *Separating precipitation and evapotranspiration from noise - a new filter routine for high resolution lysimeter data*. Hydrol. Earth Syst. Sci. Discuss., 2013. **10**(12): p. 14645-14674.

10. Durner, W., *Interactive comment on "Separating precipitation and evapotranspiration from noise - a new filter routine for high resolution lysimeter data"* by A. Peters et al. Hydrol. Earth Syst. Sci. Discuss., 2014. **10**(12): p. C7860-C7861.
A

<table><tr><td>Abbrent, M.</td><td>O39</td></tr><tr><td>Al Bitar, A.</td><td>P1 - 08</td></tr><tr><td>Al, E.</td><td>P2 - 07, P2 - 08</td></tr><tr><td>Amelung, W.</td><td>P2 - 21</td></tr><tr><td>AMMA-CATCH working group</td><td>P2 - 06</td></tr><tr><td>Andreasen, M.</td><td>O60</td></tr><tr><td>Arhonditsis, G.</td><td>P2 - 19</td></tr><tr><td>Armston, J.</td><td>O17</td></tr><tr><td>Arneth, A.</td><td>P3 - 14</td></tr><tr><td>Assad, E.</td><td>O05</td></tr><tr><td>Assing, M.</td><td>P3 - 31, P3 - 32</td></tr><tr><td>Attermeyer, K.</td><td>O26</td></tr><tr><td>Aubinet, M.</td><td>O71, P3 - 21</td></tr><tr><td>Augustin, J.</td><td>P3 - 07</td></tr><tr><td>Azadi, H.</td><td>O16</td></tr></table>

B

<table><tr><td>Baatz, R.</td><td>P3 - 42</td></tr><tr><td>Bacour, C.</td><td>O75</td></tr><tr><td>Bahn, M.</td><td>P3 - 50</td></tr><tr><td>Bamberger, I.</td><td>O12</td></tr><tr><td>Bandyopadhyay, S.</td><td>P1 - 08</td></tr><tr><td>Banwart, S.</td><td>K12</td></tr><tr><td>Basoni, A.</td><td>O36</td></tr><tr><td>Bastianini, M.</td><td>O36</td></tr><tr><td>Bateni, S. M.</td><td>O77</td></tr><tr><td>Baumgarten, A.</td><td>P1 - 18, P2 - 13</td></tr><tr><td>Baysal, G.</td><td>O40</td></tr><tr><td>Beck, I.</td><td>P3 - 17</td></tr><tr><td>Beerten, K.</td><td>P2 - 09, P3 - 06</td></tr><tr><td>Behrendt, A.</td><td>O80</td></tr><tr><td>Bendix, J.</td><td>P1 - 01</td></tr><tr><td>Bens, O.</td><td>O51, P2 - 05</td></tr><tr><td>Benskin, C.</td><td>O27</td></tr><tr><td>Bernhofer, C.</td><td>O69</td></tr><tr><td>Berthold, H.</td><td>P1 - 18, P2 - 13</td></tr><tr><td>Bertoldi, G.</td><td>P2 - 27</td></tr><tr><td>Beven, K.</td><td>O27</td></tr><tr><td>Beyrich, F.</td><td>O66</td></tr><tr><td>Bhatt, G.</td><td>K22</td></tr><tr><td>Bhattacharya, B.</td><td>P1 - 09</td></tr><tr><td>Bieber, A.</td><td>O54</td></tr><tr><td>Biernath, C.</td><td>P1 - 15, P3 - 16, P3 - 17</td></tr><tr><td>Binley, A.</td><td>O61</td></tr><tr><td>Blasch, G.</td><td>P1 - 06, P2 - 02</td></tr><tr><td>Blaum, N.</td><td>O15</td></tr><tr><td>Bloom, A. A.</td><td>K02</td></tr><tr><td>Blume, T.</td><td>P1 - 01, P2 - 25, P3 - 30, P3 - 34</td></tr><tr><td>Bodmer, P.</td><td>O26</td></tr><tr><td>Bogena, H. R.</td><td>O34, O37, O46, O60, O68, O79, P1 - 01, P2 - 15, P3 - 39</td></tr><tr><td>Bol, R.</td><td>P2 - 21</td></tr><tr><td>Borderies, P.</td><td>P1 - 02</td></tr><tr><td>Borg, E.</td><td>O38, P2 - 02, P2 - 05</td></tr><tr><td>Bossa, Y. A.</td><td>P2 - 22</td></tr></table>
<table><tr><td>Bossy, A.</td><td>P3 - 48</td></tr><tr><td>Bouchoms, S.</td><td>K15</td></tr><tr><td>Bowes, M. J.</td><td>K04</td></tr><tr><td>Boyer, E.</td><td>K22</td></tr><tr><td>Boënne, W.</td><td>O47</td></tr><tr><td>Brademann, B.</td><td>O52</td></tr><tr><td>Brancato, V.</td><td>P1 - 01</td></tr><tr><td>Brandelik, A.</td><td>P3 - 35</td></tr><tr><td>Brauer, A.</td><td>O51, O52, O54, P2 - 05, P3 - 01, P3 - 02</td></tr><tr><td>Braumann, F.</td><td>O45</td></tr><tr><td>Breitner, S.</td><td>P3 - 17</td></tr><tr><td>Brell, M.</td><td>P2 - 02</td></tr><tr><td>Briers, P.</td><td>P2 - 24</td></tr><tr><td>Brouyère, S.</td><td>P2 - 24</td></tr><tr><td>Bruckner, A.</td><td>P2 - 13</td></tr><tr><td>Brüggemann, N.</td><td>O08, O14, O84</td></tr><tr><td>Buis, S.</td><td>O48</td></tr><tr><td>Bumberger, J.</td><td>P2 - 11, P3 - 27, P3 - 31, P3 - 32</td></tr><tr><td>Busch, S.</td><td>P3 - 38</td></tr><tr><td>Butterbach-Bahl, K.</td><td>K05, O06, O11, O83, O84, P1 - 17</td></tr><tr><td>Butts, M.</td><td>O67</td></tr><tr><td>Buès, M.</td><td>P3 - 48</td></tr><tr><td>Bydalek, F.</td><td>P2 - 21</td></tr><tr><td>Böttcher, J.</td><td>P1 - 14</td></tr><tr><td>Büttner, O.</td><td>P2 - 23</td></tr></table>

C

<table><tr><td>Cadule, P.</td><td>O75</td></tr><tr><td>Calanca, P.</td><td>O78</td></tr><tr><td>Cappelaere, B.</td><td>P2 - 06</td></tr><tr><td>Capser, P.</td><td>O26</td></tr><tr><td>Carrara, P.</td><td>O36</td></tr><tr><td>Carvalhais, N.</td><td>K24</td></tr><tr><td>Chabbi, A.</td><td>K26</td></tr><tr><td>Chang, N.-B.</td><td>O42</td></tr><tr><td>Chevallier, F.</td><td>O75</td></tr><tr><td>Chmieleski, J.</td><td>O51</td></tr><tr><td>Christensen, J. H.</td><td>O67</td></tr><tr><td>Christensen, O. B.</td><td>O67</td></tr><tr><td>Christensen, S.</td><td>P2 - 14</td></tr><tr><td>Ciais, P.</td><td>O75</td></tr><tr><td>Clancy, T.</td><td>O23</td></tr><tr><td>Clasen, A.</td><td>O03</td></tr><tr><td>Collins, A.</td><td>O27</td></tr><tr><td>Conil, S.</td><td>P2 - 04</td></tr><tr><td>Corgne, S.</td><td>P1 - 08</td></tr><tr><td>Cornelis, W.</td><td>O47</td></tr><tr><td>Crawford, J.</td><td>O42</td></tr><tr><td>Cubasch, U.</td><td>P3 - 04</td></tr><tr><td>Cyrys, J.</td><td>P3 - 17</td></tr></table>

D

<table><tr><td>da Rocha, H.</td><td>O41</td></tr><tr><td>Damian, T.</td><td>O65</td></tr><tr><td>Daniel, W.</td><td>O14</td></tr></table>
<table>
  <tbody>
    <tr>
      <td>Dannenmann, M.</td>
      <td>K05, O83</td>
    </tr>
    <tr>
      <td>Dannowski, R.</td>
      <td>O33, O51</td>
    </tr>
    <tr>
      <td>Daub, B.</td>
      <td>P3 - 14</td>
    </tr>
    <tr>
      <td>David, A.</td>
      <td>O55</td>
    </tr>
    <tr>
      <td>De Lannoy, G.</td>
      <td>K25</td>
    </tr>
    <tr>
      <td>De Maeyer, P.</td>
      <td>O16</td>
    </tr>
    <tr>
      <td>de Paula Herrmann Jr, P.</td>
      <td>P3 - 33</td>
    </tr>
    <tr>
      <td>S.</td>
      <td></td>
    </tr>
    <tr>
      <td>De Roo, F.</td>
      <td>P3 - 08, P3 - 11</td>
    </tr>
    <tr>
      <td>Dechant, B.</td>
      <td>P1 - 04</td>
    </tr>
    <tr>
      <td>Deckin, U.</td>
      <td>O55</td>
    </tr>
    <tr>
      <td>Decock, C.</td>
      <td>O10</td>
    </tr>
    <tr>
      <td>Degré, A.</td>
      <td>P2 - 24</td>
    </tr>
    <tr>
      <td>Della Chiesa, S.</td>
      <td>P2 - 27</td>
    </tr>
    <tr>
      <td>Delon, C.</td>
      <td>P3 - 13</td>
    </tr>
    <tr>
      <td>Demarty, J.</td>
      <td>P2 - 06</td>
    </tr>
    <tr>
      <td>Desai, A.</td>
      <td>P3 - 11</td>
    </tr>
    <tr>
      <td>Descy, J.-P.</td>
      <td>P2 - 24</td>
    </tr>
    <tr>
      <td>Desilets, D.</td>
      <td>O60</td>
    </tr>
    <tr>
      <td>Desjardins, R.</td>
      <td>K17, P3 - 08</td>
    </tr>
    <tr>
      <td>Devaraju, A.</td>
      <td>O37</td>
    </tr>
    <tr>
      <td>Diawara, M.</td>
      <td>P3 - 13</td>
    </tr>
    <tr>
      <td>Diaz-Pinez, E.</td>
      <td>O83</td>
    </tr>
    <tr>
      <td>Diekkrüger, B.</td>
      <td>O34, P2 - 22</td>
    </tr>
    <tr>
      <td>Dietrich, O.</td>
      <td>P3 - 47</td>
    </tr>
    <tr>
      <td>Dietrich, P.</td>
      <td>P1 - 01, P2 - 11, P3 - 31, P3 - 32, P3 - 40</td>
    </tr>
    <tr>
      <td>Dietze, E.</td>
      <td>O50</td>
    </tr>
    <tr>
      <td>Doetterl, S.</td>
      <td>K15</td>
    </tr>
    <tr>
      <td>Dong, J.</td>
      <td>P3 - 41</td>
    </tr>
    <tr>
      <td>Dreibrodt, J.</td>
      <td>P3 - 30</td>
    </tr>
    <tr>
      <td>Drews, M.</td>
      <td>O67</td>
    </tr>
    <tr>
      <td>Dräger, N.</td>
      <td>O52, P3 - 01</td>
    </tr>
    <tr>
      <td>Drösler, M.</td>
      <td>P1 - 11</td>
    </tr>
    <tr>
      <td>Drüe, C.</td>
      <td>O68</td>
    </tr>
    <tr>
      <td>Duffy, C.</td>
      <td>K22</td>
    </tr>
    <tr>
      <td>Dulski, P.</td>
      <td>O52, P3 - 01</td>
    </tr>
  </tbody>
</table>

E

<table>
  <tbody>
    <tr>
      <td>Eccard, J.</td>
      <td>O15</td>
    </tr>
    <tr>
      <td>Echevarria, G.</td>
      <td>P3 - 48</td>
    </tr>
    <tr>
      <td>Eckart, E.</td>
      <td>P1 - 13</td>
    </tr>
    <tr>
      <td>Eder, F.</td>
      <td>O65, P3 - 08</td>
    </tr>
    <tr>
      <td>Eiermann, S.</td>
      <td>P1 - 01</td>
    </tr>
    <tr>
      <td>Eissenstat, D.</td>
      <td>K22</td>
    </tr>
    <tr>
      <td>Elste, S.</td>
      <td>O04</td>
    </tr>
    <tr>
      <td>Emeis, S.</td>
      <td>P1 - 14</td>
    </tr>
    <tr>
      <td>Emmenegger, L.</td>
      <td>O10</td>
    </tr>
    <tr>
      <td>Engel, M.</td>
      <td>P2 - 27</td>
    </tr>
    <tr>
      <td>Entekhabi, D.</td>
      <td>K01</td>
    </tr>
    <tr>
      <td>Epron, D.</td>
      <td>P3 - 20</td>
    </tr>
    <tr>
      <td>Evans, R.</td>
      <td>O27</td>
    </tr>
    <tr>
      <td>Everaars, J.</td>
      <td>O18, O19</td>
    </tr>
    <tr>
      <td>Exbrayat, J.-F.</td>
      <td>K02</td>
    </tr>
  </tbody>
</table>

F

<table>
  <tbody>
    <tr>
      <td>Faber, O.</td>
      <td>P2 - 03</td>
    </tr>
    <tr>
      <td>Fahle, M.</td>
      <td>P3 - 47</td>
    </tr>
    <tr>
      <td>Fang, Z.</td>
      <td>P2 - 15</td>
    </tr>
    <tr>
      <td>Fatras, C.</td>
      <td>P1 - 02</td>
    </tr>
    <tr>
      <td>Feldmann, H.</td>
      <td>O74</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>Ferraris, S.</td>
      <td>O49</td>
    </tr>
    <tr>
      <td>Fersch, B.</td>
      <td>O31, P3 - 37</td>
    </tr>
    <tr>
      <td>Finke, P.</td>
      <td>K11</td>
    </tr>
    <tr>
      <td>Fiorani, F.</td>
      <td>P3 - 33</td>
    </tr>
    <tr>
      <td>Fleckenstein, J. H.</td>
      <td>O24</td>
    </tr>
    <tr>
      <td>Fleischer, P.</td>
      <td>K07</td>
    </tr>
    <tr>
      <td>Fleischer jr, P.</td>
      <td>K07</td>
    </tr>
    <tr>
      <td>Flury, S.</td>
      <td>O26</td>
    </tr>
    <tr>
      <td>Forsius, M.</td>
      <td>K14</td>
    </tr>
    <tr>
      <td>Fox, A.</td>
      <td>P3 - 42</td>
    </tr>
    <tr>
      <td>Franz, D.</td>
      <td>P3 - 09</td>
    </tr>
    <tr>
      <td>Frappart, F.</td>
      <td>P1 - 02</td>
    </tr>
    <tr>
      <td>Frederiksen, R. R.</td>
      <td>P2 - 14</td>
    </tr>
    <tr>
      <td>Fregien, K.</td>
      <td>P3 - 05</td>
    </tr>
    <tr>
      <td>Freibauer, A.</td>
      <td>O26, O45</td>
    </tr>
    <tr>
      <td>Freitas, H.</td>
      <td>O41</td>
    </tr>
    <tr>
      <td>Frenck, G.</td>
      <td>O82, P3 - 49</td>
    </tr>
    <tr>
      <td>Frenzel, M.</td>
      <td>O18, O19</td>
    </tr>
    <tr>
      <td>Freund, M.</td>
      <td>P3 - 04</td>
    </tr>
    <tr>
      <td>Frey, S.</td>
      <td>O32</td>
    </tr>
    <tr>
      <td>Friesen, J.</td>
      <td>P3 - 23</td>
    </tr>
    <tr>
      <td>Fu, J.</td>
      <td>O83</td>
    </tr>
    <tr>
      <td>Fugazza, C.</td>
      <td>O36</td>
    </tr>
    <tr>
      <td>Förster, M.</td>
      <td>O03</td>
    </tr>
  </tbody>
</table>

G

<table>
  <tbody>
    <tr>
      <td>Gaillardet, J.</td>
      <td>O22</td>
    </tr>
    <tr>
      <td>Gaines, K.</td>
      <td>K22</td>
    </tr>
    <tr>
      <td>Galle, S.</td>
      <td>P2 - 06</td>
    </tr>
    <tr>
      <td>Galy-Lacaux, C.</td>
      <td>P3 - 13</td>
    </tr>
    <tr>
      <td>Gasche, R.</td>
      <td>O11, O83</td>
    </tr>
    <tr>
      <td>Gassen, N.</td>
      <td>P2 - 20</td>
    </tr>
    <tr>
      <td>Gast, A.</td>
      <td>P3 - 14</td>
    </tr>
    <tr>
      <td>Gaudet, J. P.</td>
      <td>O81</td>
    </tr>
    <tr>
      <td>Gea-Izquierdo, G.</td>
      <td>O53</td>
    </tr>
    <tr>
      <td>Gedeon, M.</td>
      <td>P2 - 09</td>
    </tr>
    <tr>
      <td>Georgi, C.</td>
      <td>P2 - 02</td>
    </tr>
    <tr>
      <td>Gerl, G.</td>
      <td>P1 - 16</td>
    </tr>
    <tr>
      <td>Germer, S.</td>
      <td>P3 - 30</td>
    </tr>
    <tr>
      <td>Gerwin, W.</td>
      <td>P2 - 12</td>
    </tr>
    <tr>
      <td>Gessner, M.</td>
      <td>K20, P2 - 05</td>
    </tr>
    <tr>
      <td>Geßler, A.</td>
      <td>O26</td>
    </tr>
    <tr>
      <td>Gilles-Stein, S.</td>
      <td>P3 - 17</td>
    </tr>
    <tr>
      <td>Giustarini, L.</td>
      <td>P2 - 03</td>
    </tr>
    <tr>
      <td>Glaesser, C.</td>
      <td>O04</td>
    </tr>
    <tr>
      <td>Glatzel, S.</td>
      <td>O43, O64</td>
    </tr>
    <tr>
      <td>Glemnitz, M.</td>
      <td>O15</td>
    </tr>
    <tr>
      <td>Gobiet, A.</td>
      <td>O78</td>
    </tr>
    <tr>
      <td>Gochis, D.</td>
      <td>O31</td>
    </tr>
    <tr>
      <td>Goffin, S.</td>
      <td>O71, P3 - 21</td>
    </tr>
    <tr>
      <td>Gottschalk, P.</td>
      <td>O30</td>
    </tr>
    <tr>
      <td>Gottselig, N.</td>
      <td>O08</td>
    </tr>
    <tr>
      <td>Govers, G.</td>
      <td>K15</td>
    </tr>
    <tr>
      <td>Graf, A.</td>
      <td>O68, P2 - 21</td>
    </tr>
    <tr>
      <td>Grant, R.</td>
      <td>P1 - 14</td>
    </tr>
    <tr>
      <td>Grau, T.</td>
      <td>P1 - 01</td>
    </tr>
    <tr>
      <td>Griebler, C.</td>
      <td>P2 - 20</td>
    </tr>
    <tr>
      <td>Griffith, B.</td>
      <td>P2 - 08</td>
    </tr>
    <tr>
      <td>Grippa, M.</td>
      <td>P1 - 02, P2 - 06, P3 - 13</td>
    </tr>
    <tr>
      <td>Groh, J.</td>
      <td>P3 - 51</td>
    </tr>
    <tr>
      <td>Groppo, J.</td>
      <td>O05</td>
    </tr>
  </tbody>
</table>
<table><tr><td>Gross, P.</td><td>P2 - 04</td></tr><tr><td>Grossart, H.-P.</td><td>O26</td></tr><tr><td>Grote, R.</td><td>O07</td></tr><tr><td>Guerif, M.</td><td>O48</td></tr><tr><td>Guiot, J.</td><td>O53</td></tr><tr><td>Guiro, I.</td><td>P1 - 02</td></tr><tr><td>Götze, C.</td><td>O04</td></tr><tr><td>Güntner, A.</td><td>P1 - 01, P2 - 05, P2 - 25, P3 - 02, P3 - 30, P3 - 34</td></tr></table>

H

<table><tr><td>Haarder, E.</td><td>O61</td></tr><tr><td>Haas, E.</td><td>O06, O07, P1 - 17</td></tr><tr><td>Haeuser, C.</td><td>K03</td></tr><tr><td>Hagemann, U.</td><td>P3 - 07</td></tr><tr><td>Hahn, J.</td><td>O43</td></tr><tr><td>Hajnsek, I.</td><td>O01, P1 - 01</td></tr><tr><td>Hallet, V.</td><td>P2 - 24</td></tr><tr><td>Halliday, S. J.</td><td>K04</td></tr><tr><td>Hammerle, A.</td><td>O12, O78</td></tr><tr><td>Han, X.</td><td>O79, P3 - 42</td></tr><tr><td>Hansel, A.</td><td>O12</td></tr><tr><td>Harahap, M.</td><td>P3 - 12</td></tr><tr><td>Hardelauf, H.</td><td>O68</td></tr><tr><td>Harris, E.</td><td>P3 - 26</td></tr><tr><td>Harris, P.</td><td>P2 - 07</td></tr><tr><td>Hauck, J.</td><td>P3 - 17</td></tr><tr><td>Haut, B.</td><td>O71</td></tr><tr><td>Haygarth, P.</td><td>O27</td></tr><tr><td>He, G.</td><td>P3 - 46</td></tr><tr><td>Heid, L.</td><td>P2 - 04</td></tr><tr><td>Heidbach, K.</td><td>P1 - 13</td></tr><tr><td>Heidbüchel, I.</td><td>P1 - 01, P3 - 34</td></tr><tr><td>Heine, I.</td><td>O50, O51, P1 - 10</td></tr><tr><td>Heinemann, G.</td><td>O68</td></tr><tr><td>Heinlein, F.</td><td>P1 - 15, P3 - 16, P3 - 17, P3 - 19</td></tr><tr><td>Heinrich, I.</td><td>O51, O53, O54, P3 - 04, P3 - 05</td></tr><tr><td>Helle, G.</td><td>O53, O54, P3 - 04, P3 - 05</td></tr><tr><td>Hendrey, G.</td><td>O09</td></tr><tr><td>Hendricks-Franssen, H.-J.</td><td>O79, P1 - 01, P3 - 42, P3 - 45, P3 - 43, P3 - 46</td></tr><tr><td>Henkel, J.</td><td>O51</td></tr><tr><td>Herbst, M.</td><td>O20</td></tr><tr><td>Herndl, M.</td><td>P3 - 50</td></tr><tr><td>Heupel, K.</td><td>P2 - 02</td></tr><tr><td>Heußner, K.-U.</td><td>O51, O54</td></tr><tr><td>Hiernaux, P.</td><td>P3 - 13</td></tr><tr><td>Hildebrandt, A.</td><td>P3 - 23</td></tr><tr><td>Hilt, S.</td><td>O26</td></tr><tr><td>Hinz, C.</td><td>P2 - 12</td></tr><tr><td>Hiscock, K.</td><td>O27</td></tr><tr><td>Hoar, T.</td><td>P3 - 42</td></tr><tr><td>Hoffmann, C.</td><td>O26</td></tr><tr><td>Hoffmann, T.</td><td>K15</td></tr><tr><td>Hofmann, J.</td><td>O64</td></tr><tr><td>Hohmann, C.</td><td>O02, P1 - 06, P2 - 02</td></tr><tr><td>Hollaway, M.</td><td>O27</td></tr><tr><td>Holmes, G.</td><td>K22</td></tr><tr><td>Hommeltenberg, J.</td><td>O07, P1 - 11</td></tr><tr><td>Hong, J.</td><td>O13, P3 - 18</td></tr><tr><td>Hong, J.-W.</td><td>O13</td></tr><tr><td>Hong, S.-Y.</td><td>P3 - 18</td></tr></table>
<table><tr><td>Huber, J.</td><td>P2 - 16</td></tr><tr><td>Huisman, J. A.</td><td>O46, O62, P3 - 39</td></tr><tr><td>Huq, S.</td><td>P3 - 11</td></tr><tr><td>Hutschenreuther, T.</td><td>P2 - 11, P3 - 32</td></tr><tr><td>Hwang, H.-T.</td><td>O32</td></tr><tr><td>Hörtnagl, L.</td><td>O12</td></tr><tr><td>Hösch, J.</td><td>P1 - 18, P2 - 13</td></tr><tr><td>Hübener, T.</td><td>P3 - 01</td></tr><tr><td>Hübner, C.</td><td>P3 - 35</td></tr><tr><td>Hülsmann, S.</td><td>O58</td></tr><tr><td>Hüttl, R. F.</td><td>P2 - 12</td></tr></table>

I

<table><tr><td>Iffly, J. F.</td><td>P2 - 03</td></tr><tr><td>Itzerott, S.</td><td>O02, O03, O50, P1 - 01, P1 - 10, P2 - 02, P2 - 05</td></tr></table>

J

<table><tr><td>Jaconi, A.</td><td>O26</td></tr><tr><td>Jagdhuber, T.</td><td>O01, P1 - 01</td></tr><tr><td>Jahncke, D.</td><td>P2 - 02</td></tr><tr><td>Jahnke, S.</td><td>P3 - 33</td></tr><tr><td>Jarvie, H. P.</td><td>K04</td></tr><tr><td>Jeltsch, F.</td><td>O15</td></tr><tr><td>Jensen, K. H.</td><td>O09, O21, O29, O60, O61, O67</td></tr><tr><td>Jiang, S.</td><td>O25, P2 - 23</td></tr><tr><td>Jin, L.</td><td>K22</td></tr><tr><td>Jomaa, S.</td><td>O25, P2 - 23</td></tr><tr><td>Jonard, F.</td><td>P1 - 01</td></tr><tr><td>Joris, I.</td><td>O47</td></tr><tr><td>Joshi, J.</td><td>O15</td></tr><tr><td>Jurasinski, G.</td><td>O43, O64, P2 - 05</td></tr><tr><td>Juszczak, R.</td><td>P1 - 17</td></tr></table>

K

<table><tr><td>Kahana, R.</td><td>O27</td></tr><tr><td>Kaiser, K.</td><td>O51, P2 - 05</td></tr><tr><td>Kaiser, T.</td><td>P3 - 47</td></tr><tr><td>Kalettka, T.</td><td>O26</td></tr><tr><td>Kalthoff, N.</td><td>P3 - 35</td></tr><tr><td>Karnieli, A.</td><td>P1 - 05</td></tr><tr><td>Kasprzak, P.</td><td>K20</td></tr><tr><td>Katata, G.</td><td>P3 - 10</td></tr><tr><td>Katul, G. G.</td><td>O70</td></tr><tr><td>Kayler, Z.</td><td>O26</td></tr><tr><td>Kazanjian, G.</td><td>O26</td></tr><tr><td>Kergoat, L.</td><td>P3 - 13</td></tr><tr><td>Kerr, Y.</td><td>P1 - 08</td></tr><tr><td>Khedrigharibvand, H.</td><td>O16</td></tr><tr><td>Khodayar, S.</td><td>O74</td></tr><tr><td>Kienel, U.</td><td>O52, P3 - 01</td></tr><tr><td>Kiese, R.</td><td>K05, O06, O11, O83, O84, P1 - 12, P1 - 17</td></tr><tr><td>Kilian, P.</td><td>P1 - 03</td></tr><tr><td>Kimball, B.</td><td>P3 - 50</td></tr><tr><td>Kiseleva, O.</td><td>P3 - 35</td></tr><tr><td>Kitzler, B.</td><td>P1 - 18, P2 - 13</td></tr><tr><td>Klatt, S.</td><td>O06</td></tr><tr><td>Kleeberg, A.</td><td>O26</td></tr><tr><td>Kleidon, A.</td><td>O69</td></tr><tr><td>Klein, C.</td><td>P1 - 15, P3 - 16, P3 - 17</td></tr></table>
<table>
  <tbody>
    <tr>
      <td>Kleinschmit, B.</td>
      <td>O03</td>
    </tr>
    <tr>
      <td>Kliment, T.</td>
      <td>O36</td>
    </tr>
    <tr>
      <td>Klinke, R.</td>
      <td>P2 - 02</td>
    </tr>
    <tr>
      <td>Klotzsche, A.</td>
      <td>P3 - 38</td>
    </tr>
    <tr>
      <td>Klump, J.</td>
      <td>P2 - 01</td>
    </tr>
    <tr>
      <td>Klumpp, K.</td>
      <td>P2 - 04</td>
    </tr>
    <tr>
      <td>Knorr, A.</td>
      <td>O54</td>
    </tr>
    <tr>
      <td>Koal, P.</td>
      <td>P1 - 16</td>
    </tr>
    <tr>
      <td>Koch, J.</td>
      <td>O29</td>
    </tr>
    <tr>
      <td>Koch, M.</td>
      <td>O43, O64</td>
    </tr>
    <tr>
      <td>Koch, S.</td>
      <td>O43</td>
    </tr>
    <tr>
      <td>Koebsch, F.</td>
      <td>O43, O64, P3 - 09</td>
    </tr>
    <tr>
      <td>Kohler, M.</td>
      <td>P3 - 35</td>
    </tr>
    <tr>
      <td>Kohnert, K.</td>
      <td>P3 - 08, P3 - 09</td>
    </tr>
    <tr>
      <td>Kolditz, O.</td>
      <td>O39</td>
    </tr>
    <tr>
      <td>Kollet, S.</td>
      <td>O73, P2 - 15, P3 - 15, P3 - 24, P3 - 46</td>
    </tr>
    <tr>
      <td>Kopp, B.</td>
      <td>P2 - 17</td>
    </tr>
    <tr>
      <td>Kottmeier, C.</td>
      <td>O74, P3 - 35</td>
    </tr>
    <tr>
      <td>Kraus, D.</td>
      <td>O06</td>
    </tr>
    <tr>
      <td>Krause, S.</td>
      <td>K13</td>
    </tr>
    <tr>
      <td>Krieg, R.</td>
      <td>P3 - 37</td>
    </tr>
    <tr>
      <td>Krishnan Kutty, S.</td>
      <td>O48</td>
    </tr>
    <tr>
      <td>Kugler, F.</td>
      <td>P1 - 07</td>
    </tr>
    <tr>
      <td>Kumar, R.</td>
      <td>P3 - 28</td>
    </tr>
    <tr>
      <td>Kumbhar, P.</td>
      <td>P3 - 42</td>
    </tr>
    <tr>
      <td>Kunkel, R.</td>
      <td>O37</td>
    </tr>
    <tr>
      <td>Kunstmann, H.</td>
      <td>O31, P1 - 01, P3 - 37</td>
    </tr>
    <tr>
      <td>Kunz, V.</td>
      <td>P2 - 18</td>
    </tr>
    <tr>
      <td>Kurian, M.</td>
      <td>O58</td>
    </tr>
    <tr>
      <td>Kurtz, W.</td>
      <td>P1 - 01, P3 - 45, P3 - 46</td>
    </tr>
    <tr>
      <td>Kämpf, L.</td>
      <td>P3 - 02</td>
    </tr>
    <tr>
      <td>Kögler, S.</td>
      <td>P3 - 29</td>
    </tr>
    <tr>
      <td>Königer, F.</td>
      <td>P3 - 35</td>
    </tr>
    <tr>
      <td>Küster, M.</td>
      <td>O51</td>
    </tr>
  </tbody>
</table>

L

<table>
  <tbody>
    <tr>
      <td>Laggner, A.</td>
      <td>O45</td>
    </tr>
    <tr>
      <td>Lampe, R.</td>
      <td>P2 - 05</td>
    </tr>
    <tr>
      <td>Lange, M.</td>
      <td>P1 - 04</td>
    </tr>
    <tr>
      <td>Langensiepen, M.</td>
      <td>P3 - 24</td>
    </tr>
    <tr>
      <td>Lapteva, Y.</td>
      <td>P3 - 27</td>
    </tr>
    <tr>
      <td>Larmanou, E.</td>
      <td>P3 - 09</td>
    </tr>
    <tr>
      <td>Larsen, M. A. D.</td>
      <td>O67</td>
    </tr>
    <tr>
      <td>Launiainen, S.</td>
      <td>O70</td>
    </tr>
    <tr>
      <td>Lauren, A.</td>
      <td>O70</td>
    </tr>
    <tr>
      <td>Lebel, T.</td>
      <td>P2 - 06</td>
    </tr>
    <tr>
      <td>Lee, J.</td>
      <td>P3 - 18</td>
    </tr>
    <tr>
      <td>Lee, K.</td>
      <td>O13</td>
    </tr>
    <tr>
      <td>Lehmann, A.</td>
      <td>P1 - 01</td>
    </tr>
    <tr>
      <td>Lehr, C.</td>
      <td>O33</td>
    </tr>
    <tr>
      <td>Leitinger, G.</td>
      <td>O82, P3 - 49</td>
    </tr>
    <tr>
      <td>Leonard, S.</td>
      <td>O75</td>
    </tr>
    <tr>
      <td>Lesny, J.</td>
      <td>P1 - 17</td>
    </tr>
    <tr>
      <td>Leterme, B.</td>
      <td>P2 - 09, P3 - 06</td>
    </tr>
    <tr>
      <td>Lewandowski, J.</td>
      <td>K20</td>
    </tr>
    <tr>
      <td>Leyval, C.</td>
      <td>K27, P3 - 48</td>
    </tr>
    <tr>
      <td>Liebner, S.</td>
      <td>P2 - 05</td>
    </tr>
    <tr>
      <td>Lin, H.</td>
      <td>K19</td>
    </tr>
    <tr>
      <td>Lindauer, M.</td>
      <td>O07</td>
    </tr>
    <tr>
      <td>Lisboa, C.</td>
      <td>O26</td>
    </tr>
    <tr>
      <td>Lischeid, G.</td>
      <td>O24, O26, O33, O51, P2 - 05, P2 - 19</td>
    </tr>
  </tbody>
</table>
Liu, S. O08, P3 - 44
Loewenthal, M. K04
Longdoz, B. O71, P2 - 04, P3 - 20, P3 - 21
Longuevergne, L. O22
Looms, M. C. O60, O61
Lorenz, C. P1 - 01
Lorenz, S. P3 - 01
Lowe, A. O17, O23
Lu, H. O11, O83
Luterbacher, J. O45
Lücke, A. O34, P2 - 21
Lüttger, A. O30

M

MacBean, N. O75
Macleod, C. O27, O44
Maier, M. O71, P3 - 20, P3 - 21
Maignan, F. O75
Mannschatz, T. O58
Martin, T. O41
Martini, E. P3 - 29
Martins, J. M. F. O81
Martins, S. O05
Marzahn, P. P1 - 01
Mauder, M. O65, P1 - 11, P1 - 13, P3 - 08, P3 - 10, P3 - 11
Members, I. P3 - 04
Menegon, S. O36
Merbold, L. O10
Merz, B. P3 - 02
Merz, C. O33
Merz, R. P3 - 37
Mester, A. O62
Metzger, J. O56
Metzger, S. P3 - 11
MGinnis, D. F. O26
Michel, K. P1 - 18, P2 - 13
Missling, K.-D. O38
Moderow, U. O69
Mohiuddin, G. O42
Mohn, J. O10
Molch, K. O38
Molina Herrera, S. O06
Mollenhauer, H. P2 - 11, P3 - 31, P3 - 32
Mollenhauer, O. P3 - 31, P3 - 32
P1 - 01
Montzka, C. P3 - 30
Morgner, M. O41
Mota da Silva, J. P1 - 10
Motagh, M. P1 - 02, P2 - 06, P3 - 13
Mougin, E. O48, P1 - 08, P1 - 09
Muddu, S. P3 - 02
Mueller, P. O17
Muir, J. P1 - 16, P3 - 17
Munch, J. C. P2 - 13
Murer, E. P2 - 13
Musolff, A. O24, P2 - 20

N

Natkhin, M. O51
Navel, A. O81
<table><tr><td>Nendel, C.</td><td>P3 - 07</td></tr><tr><td>Neres, N.</td><td>O41</td></tr><tr><td>Neumann, J.</td><td>P2 - 17</td></tr><tr><td>Neuwirth, B.</td><td>P3 - 05</td></tr><tr><td>Niedrist, G.</td><td>P2 - 27, P3 - 49</td></tr><tr><td>Nielsen, L.</td><td>O61</td></tr><tr><td>Nitzsche, K.</td><td>O26</td></tr><tr><td>Niu, G.-Y.</td><td>O76</td></tr><tr><td>Notarnicola, C.</td><td>P2 - 27</td></tr><tr><td>Nyckowiak, J.</td><td>P1 - 17</td></tr></table>

O

<table><tr><td>Obojes, N.</td><td>O82, P3 - 49</td></tr><tr><td>Ockenden, M.</td><td>O27</td></tr><tr><td>Oggioni, A.</td><td>O36</td></tr><tr><td>Olejnik, J.</td><td>P1 - 17</td></tr><tr><td>Omari, M.</td><td>O26, P2 - 19</td></tr><tr><td>Orban, P.</td><td>P2 - 24</td></tr><tr><td>Ott, F.</td><td>O52, P3 - 01</td></tr></table>

P

<table><tr><td>Paasche, H.</td><td>O59, P3 - 40</td></tr><tr><td>Pangle, L.</td><td>O76</td></tr><tr><td>Paniconi, C.</td><td>O76</td></tr><tr><td>Papathanassiou, K.</td><td>O01, P1 - 07</td></tr><tr><td>Pardini, M.</td><td>P1 - 07</td></tr><tr><td>Parent, F.</td><td>P3 - 20, P3 - 21</td></tr><tr><td>Park, C.-H.</td><td>O80</td></tr><tr><td>Park, Y.-J.</td><td>O32</td></tr><tr><td>Pasetto, D.</td><td>O76</td></tr><tr><td>Pause, M.</td><td>O80</td></tr><tr><td>Pavão, E.</td><td>O05</td></tr><tr><td>Pepe, M.</td><td>O36</td></tr><tr><td>Peters, A.</td><td>P3 - 17</td></tr><tr><td>Petruschke, S.</td><td>O39</td></tr><tr><td>Peugeot, C.</td><td>P2 - 06</td></tr><tr><td>Peylin, P.</td><td>O75</td></tr><tr><td>Pfister, L.</td><td>P2 - 03</td></tr><tr><td>Phinn, S.</td><td>O17, O23</td></tr><tr><td>Piepho, H. P.</td><td>P3 - 50</td></tr><tr><td>Pinto, H.</td><td>O05</td></tr><tr><td>Pirhofer-Walzl, K.</td><td>O15, O26</td></tr><tr><td>Plain, C.</td><td>P3 - 20, P3 - 21</td></tr><tr><td>Plessen, B.</td><td>O52, P3 - 01</td></tr><tr><td>Pohl, M.</td><td>P3 - 07</td></tr><tr><td>Pospichal, B.</td><td>P1 - 03</td></tr><tr><td>Post, H.</td><td>P3 - 42</td></tr><tr><td>Premke, K.</td><td>O26</td></tr><tr><td>Priesack, E.</td><td>P1 - 15, P3 - 16, P3 - 17, P3 - 22, P3 - 36, P3 - 39</td></tr><tr><td>Pritsch, K.</td><td>P1 - 16</td></tr><tr><td>Putti, M.</td><td>O76</td></tr><tr><td>Pätzig, M.</td><td>O26</td></tr><tr><td>Pötsch, E. M.</td><td>P3 - 50</td></tr><tr><td>Pütz, T.</td><td>O14, O68, P3 - 51</td></tr></table>

Q

<table><tr><td>Qu, W.</td><td>P3 - 39</td></tr></table>