@article{vanderMeijTemmeLinetal.2018, author = {van der Meij, Marijn W. and Temme, Arnaud J. A. M. and Lin, H. S. and Gerke, Horst H. and Sommer, Michael}, title = {On the role of hydrologic processes in soil and landscape evolution modeling}, series = {Earth science reviews : the international geological journal bridging the gap between research articles and textbooks}, volume = {185}, journal = {Earth science reviews : the international geological journal bridging the gap between research articles and textbooks}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-8252}, doi = {10.1016/j.earscirev.2018.09.001}, pages = {1088 -- 1106}, year = {2018}, abstract = {The ability of water to transport and transform soil materials is one of the main drivers of soil and landscape development. In turn, soil and landscape properties determine how water is distributed in soil landscapes. Understanding the complex dynamics of this co-evolution of soils, landscapes and the hydrological system is fundamental in adapting land management to changes in climate. Soil-Landscape Evolution Models (SLEMs) are used to simulate the development and evolution of soils and landscapes. However, many hydrologic processes, such as preferential flow and subsurface lateral flow, are currently absent in these models. This limits the applicability of SLEMs to improve our understanding of feedbacks in the hydro-pedo-geomorphological system. Implementation of these hydrologic processes in SLEMs faces several complications related to calculation demands, limited methods for linking pedogenic and hydrologic processes, and limited data on quantification of changes in the hydrological system over time. In this contribution, we first briefly review processes and feedbacks in soil-landscape-hydrological systems. Next, we elaborate on the development required to include these processes in SLEMs. We discuss the state-of-the-art knowledge, identify complications, give partial solutions and suggest important future development. The main requirements for incorporating hydrologic processes in SLEMs are: (1) designing a model framework that can deal with varying timescales for different sets of processes, (2) developing and implementing methods for simulating pedogenesis as a function of water flow, (3) improving and implementing knowledge on the evolution and dynamics of soil hydraulic properties over different timescales, and (4) improving the database on temporal changes and dynamics of flow paths.}, language = {en} } @article{HerbrichGerkeSommer2018, author = {Herbrich, Marcus and Gerke, Horst H. and Sommer, Michael}, title = {Root development of winter wheat in erosion-affected soils depending on the position in a hummocky ground moraine soil landscape}, series = {Journal of plant nutrition and soil science = Zeitschrift f{\"u}r Pflanzenern{\"a}hrung und Bodenkunde}, volume = {181}, journal = {Journal of plant nutrition and soil science = Zeitschrift f{\"u}r Pflanzenern{\"a}hrung und Bodenkunde}, number = {2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1436-8730}, doi = {10.1002/jpln.201600536}, pages = {147 -- 157}, year = {2018}, abstract = {Agricultural soil landscapes of hummocky ground moraines are characterized by 3D spatial patterns of soil types that result from profile modifications due to the combined effect of water and tillage erosion. We hypothesize that crops reflect such soil landscape patterns by increased or reduced plant and root growth. Root development may depend on the thickness and vertical sequence of soil horizons as well as on the structural development state of these horizons at different landscape positions. The hypotheses were tested using field data of the root density (RD) and the root lengths (RL) of winter wheat using the minirhizotron technique. We compared data from plots at the CarboZALF-D site (NE Germany) that are representing a non-eroded reference soil profile (Albic Luvisol) at a plateau position, a strongly eroded profile at steep slope (Calcaric Regosol), and a depositional profile at the footslope (Anocolluvic Regosol). At each of these plots, three Plexiglas access tubes were installed down to approx. 1.5 m soil depth. Root measurements were carried out during the growing season of winter wheat (September 2014-August 2015) on six dates. The root length density (RLD) and the root biomass density were derived from RD values assuming a mean specific root length of 100 m g(-1). Values of RD and RLD were highest for the Anocolluvic Regosol and lowest for the Calcaric Regosol. The maximum root penetration depth was lower in the Anocolluvic Regosol because of a relatively high and fluctuating water table at this landscape position. Results revealed positive relations between below-ground (root) and above-ground crop parameters (i.e., leaf area index, plant height, biomass, and yield) for the three soil types. Observed root densities and root lengths in soils at the three landscape positions corroborated the hypothesis that the root system was reflecting erosion-induced soil profile modifications. Soil landscape position dependent root growth should be considered when attempting to quantify landscape scale water and element balances as well as agricultural productivity.}, language = {en} } @article{FilipovicGerkeFilipovicetal.2018, author = {Filipovic, Vilim and Gerke, Horst H. and Filipovic, Lana and Sommer, Michael}, title = {Quantifying subsurface lateral flow along sloping horizon boundaries in soil profiles of a hummocky ground moraine}, series = {Vadose zone journal}, volume = {17}, journal = {Vadose zone journal}, number = {1}, publisher = {Soil Science Society of America}, address = {Madison}, issn = {1539-1663}, doi = {10.2136/vzj2017.05.0106}, pages = {12}, year = {2018}, abstract = {Subsurface lateral flow in hillslope soils depends on lower permeability or texture-contrasting soil horizons. In the arable hummocky soil landscape, erosion processes caused glacial till appearance closer to the soil surface at upslope positions. The objective of this work was to quantify the potential for subsurface lateral flow depending on the erosion-affected spatial hydropedological complexity. The eroded Haplic Luvisol profile was studied due to the presence of a relatively dense C horizon that varied in depth, thickness, and sloping angle. A two-dimensional numerical modeling and sensitivity analysis for the saturated hydraulic conductivity (K-s) of the C horizon and the depth to C horizon (i.e., soil solum thickness) was performed for rainstorms in 2011 and 2012 using HYDRUS-2D. A K-s value of <2.5 cm d(-1) for the C horizon was required for lateral flow initiation. Lateral flow was (i) increasing with decreasing solum thickness, indicating an erosion-induced feedback on subsurface lateral flow, and (ii) dependent on the soil moisture regime prior to rainstorms. The effect of lateral flow on the movement of a conservative tracer was simulated in the form of a "virtual experiment". Simulation scenarios revealed only a relatively small lateral shift of the tracer plume caused by a local decoupling of water (already lateral) from subsequent tracer movement (still vertical). Longer term simulations suggested that, for the present conditions, lateral flow was limited mostly to occasional summer storm events. Even without considering preferential flow contribution to lateral flow, highly complex hydropedologic interactions are present in erosion-affected heterogeneous soil profiles.}, language = {en} } @article{GerkeKoszinskiKalettkaetal.2010, author = {Gerke, Horst H. and Koszinski, Sylvia and Kalettka, Thomas and Sommer, Michael}, title = {Structures and hydrologic function of soil landscapes with kettle holes using an integrated hydropedological approach}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2009.12.047}, year = {2010}, abstract = {The hummocky post-glacial soil landscapes with kettle holes as internal drainage systems are characterized by ponds that trap lateral fluxes in topographic depressions. A quantitative description is mostly limited by the unknown complexity of hydraulically relevant soil and sediment structures. This paper is focussing on a structure-based approach to identify relevant field-scale flow and transport processes. Illustrative examples demonstrate extreme variations in water table fluctuation for adjoining kettle holes. Explanations require a pedohydrologic concept of the arable soil landscape. Identification of structures is based on geophysical methods and soil hydraulic measurements. Electrical resistivity imaging yields 0.5 m-scale spatial structures that correspond with soil texture distributions. Electromagnetic induction provides larger-scale field maps that reflect major soil and sediment features. Results of both methods correspond within the limits of the different spatial resolutions. With geophysical exploration methods, colluvial areas with textural differences between upper and deeper soil layers, coarse-textured sediment lenses, and stony colluvial regions around kettle holes are identified as potentially relevant flow structures. The colluvial fringe around the pond seems to be a sensitive area with important lateral exchange fluxes. Tensiometer measurements perpendicular to this boundary indicate hydraulic gradients directed from the pond towards the partially saturated soil. The localized infiltration of trapped water in kettle holes can control large fractions of ground water recharge and may have implications for the fate of agricultural chemicals in post-glacial landscapes. While surface and subsurface hydraulic structures may be inferred using minimal-invasive techniques, better understanding of processes and properties governing lateral exchange fluxes between pond and surrounding soil are required.}, language = {en} } @article{KoszinskiGerkeHieroldetal.2013, author = {Koszinski, Sylvia and Gerke, Horst H. and Hierold, Wilfried and Sommer, Michael}, title = {Geophysical-based modeling of a kettle hole catchment of the morainic soil landscape}, series = {Vadose zone journal}, volume = {12}, journal = {Vadose zone journal}, number = {4}, publisher = {Soil Science Society of America}, address = {Madison}, issn = {1539-1663}, doi = {10.2136/vzj2013.02.0044}, pages = {18}, year = {2013}, abstract = {Soilscapes of the post-glacial morainic regions of the youngest glaciation are characterized by small hydrological kettle hole catchments forming hummocky soil landscapes. The spatial heterogeneity of subsurface structures as well as erosion-controlled pedogenesis under arable land use may complicate hydrological modeling. Our aim was to generate a soil landscape model for a small representative kettle hole catchment based on geoelectrical exploration and soil profile information. For a 1-ha catchment located in the northeastern German lowlands near the town of Prenzlau, electrical resistivity transects were determined by a multi electrode system (IMPETUS 12 Fs) and electrical conductivity (ECa) was mapped by using the electromagnetic induction (EMI) device EM38DD in both the vertical and horizontal modes. The 1-m digital elevation model (DEM) was obtained by kriging from high resolution manual elevation data determined with a leveling device (ZEISS Ni 40). Soil profile data from 26 boreholes distributed radially around the central pond were used to identify boundaries between soil horizons. The soil is characterized by varying topography and morphology of diagnostic horizons such as M- (colluvium), Bt- (clay illuviation), and C- (parent glacial till). By EMI mapping we identified (i) the boundary between erosive and colluvial areas around the kettle hole, and modeled (ii) the subsurface morphology of loamy horizons. Electrical resistivity tomography results coincide with these findings and allow for distinguishing between sandy and loamy dominated areas both in vertical and horizontal direction, respectively. This soil model of soil textural properties could be used for hydrological modeling.}, language = {en} } @article{RieckhGerkeSiemensetal.2014, author = {Rieckh, Helene and Gerke, Horst H. and Siemens, Jan and Sommer, Michael}, title = {Water and dissolved carbon fluxes in an eroding soil landscape depending on terrain position}, series = {Vadose zone journal}, volume = {13}, journal = {Vadose zone journal}, number = {7}, publisher = {Soil Science Society of America}, address = {Madison}, issn = {1539-1663}, doi = {10.2136/vzj2013.10.0173}, pages = {14}, year = {2014}, abstract = {Leaching of dissolved C in arable hummocky ground moraine soil landscapes is characterized by a spatial continuum of more or less erosion-affected Luvisols, Calcaric Regosols at exposed positions, and Colluvic Regosols in depressions. Our objective was to estimate the fluxes of dissolved C in four differently eroded soils as affected by erosion-induced pedological and soil structural alterations. In this model study, we considered landscape position effects by adapting the water table as the bottom boundary condition and erosion effects by using pedon-specific soil hydraulic properties. The one-dimensional vertical water movement was described with the Richards equation using HYDRUS-1D. Solute fluxes were obtained by combining calculated water fluxes with concentrations of dissolved organic and inorganic C (DOC and DIC, respectively) measured from soil solution extracted by suction cups at biweekly intervals. In the 3-yr period (2010-2012), DOC fluxes in the 2-m soil depth were similar at the three non-colluvic locations with -0.8 +/- 0.1 g m(-2) yr(-1) (i.e., outflow) but were 0.4 g m(-2) yr(-1) (i.e., input) in the depression. The DIC fluxes ranged from -10.2 g m(-2) yr(-1) for the eroded Luvisol, -9.2 g m(-2) yr(-1) for the Luvisol, and -6.1 g m(-2) yr(-1) for the Calcaric Regosol to 3.2 g m(-2) yr(-1) for the Colluvic Regosol. The temporal variations in DOC and DIC fluxes were controlled by water fluxes. The spatially distributed leaching results corroborate the hypothesis that the effects of soil erosion influence fluxes through modified hydraulic and transport properties and terrain-dependent boundary conditions.}, language = {en} } @article{RieckhGerkeSommer2012, author = {Rieckh, Helene and Gerke, Horst H. and Sommer, Michael}, title = {Hydraulic properties of characteristic horizons depending on relief position and structure in a hummocky glacial soil landscape}, series = {Soil \& tillage research : an international journal on research and development in soil tillage and field traffic, and their relationships with soil environment, land use and crop production}, volume = {125}, journal = {Soil \& tillage research : an international journal on research and development in soil tillage and field traffic, and their relationships with soil environment, land use and crop production}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-1987}, doi = {10.1016/j.still.2012.07.004}, pages = {123 -- 131}, year = {2012}, abstract = {The hummocky ground moraine soil landscape forms a spatial continuum of more or less eroded and depositional soils developed from glacial till under intensive agricultural cultivation. Measurements of soil hydraulic properties in the laboratory on soil cores are mostly limited to some characteristic horizons. However, these horizons can vary in thickness or structural and pedological development depending on relief position. This paper compares soil hydraulic properties of the same soil horizons sampled at different relief positions in a single field representing various degrees of soil erosion/deposition. Water retention curves were determined from undisturbed core samples using sand and kaolin beds with hanging water column and pressure chambers, and the unsaturated hydraulic conductivity using the double-membrane apparatus. Data were fitted to the van Genuchten-Mualem function (VGM) using the nonlinear curve fitting program RETC. The desorption water retention curves for the soil horizons were different and depended on the soil structural development that could be related with the intensity of erosion history at each landscape position. The greatest differences in hydraulic functions were found for the E, Bt, and C horizons. The fitted soil water retention curves reflected these differences mainly in the values of the VGM curve parameters n and theta(s). The landscape features that have the strongest differentiating effect are related to erosion and distance towards the water table. The results can help improving pedotransfer approaches for the estimation of spatially distributed hydraulic parameters for modelling the water movement in hummocky soil landscapes as basis for establishing landscape scale water and element balances.}, language = {en} } @article{GerkeRieckhSommer2016, author = {Gerke, Horst H. and Rieckh, Helene and Sommer, Michael}, title = {Interactions between crop, water, and dissolved organic and inorganic carbon in a hummocky landscape with erosion-affected pedogenesis}, series = {Macromolecular rapid communications}, volume = {156}, journal = {Macromolecular rapid communications}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-1987}, doi = {10.1016/j.still.2015.09.003}, pages = {230 -- 244}, year = {2016}, abstract = {Hummocky soil landscapes are characterized by 3D spatial patterns of soil types that result from erosion-affected pedogenesis. Due to tillage and water erosion, truncated profiles have been formed at steep and mid slopes and colluvial soils at hollows, while intact profiles remained at plateau positions. Pedogenetic variations in soil horizons lead to spatial differences in the soil water balance at hillslope positions. Here, possible interactions between erosion affected soil properties, the water balances, and the crop growth and feedback effects of erosion on the leaching rates were assumed. The hypothesis was tested by water balance simulations comparing uniform with hillslope position-specific crop and root growths for soils at plateau, flat mid slope, steep slope, and hollow using the Hydrus-1D program. The boundary condition data were monitored at the CarboZALF-D experimental field site, which was cropped with perennial lucerne (Medicago sativa L.) in 2013 and 2014. Crop and root growth at the four hillslope positions was assumed proportional to observed leaf area index (LAI). Fluxes of dissolved organic and inorganic carbon (DOC, DIC) were obtained from simulated water fluxes and measured DOC and DIC concentrations. For the colluvic soil at hollow, the crop growth was initially highest and later limited by an increasing water table; here the predominately upward flow led to a net input in DIC and DOC. For the truncated soils at steep slopes, simulations support the hypothesis that reduced crop growth caused an increase in percolation and DIC leaching from the subsoil horizons, which in turn led to accelerated soil development and more soil variations along eroding hillslopes in arable soil landscapes. (C) 2015 Elsevier B.V. All rights reserved.}, language = {en} } @article{LeueGerkeGodow2015, author = {Leue, Martin and Gerke, Horst H. and Godow, Sophie C.}, title = {Droplet infiltration and organic matter composition of intact crack and biopore surfaces from clay-illuvial horizons}, series = {Journal of plant nutrition and soil science = Zeitschrift f{\"u}r Pflanzenern{\"a}hrung und Bodenkunde}, volume = {178}, journal = {Journal of plant nutrition and soil science = Zeitschrift f{\"u}r Pflanzenern{\"a}hrung und Bodenkunde}, number = {2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1436-8730}, doi = {10.1002/jpln.201400209}, pages = {250 -- 260}, year = {2015}, abstract = {The organic matter (OM) in biopore walls and aggregate coatings may be important for sorption of reactive solutes and water as well as for solute mass exchange between the soil matrix and the preferential flow (PF) domains in structured soil. Structural surfaces are coated by illuvial clay-organic material and by OM of different origin, e.g., earthworm casts and root residues. The objectives were to verify the effect of OM on wettability and infiltration of intact structural surfaces in clay-illuvial horizons (Bt) of Luvisols and to investigate the relevance of the mm-scale distribution of OM composition on the water and solute transfer. Intact aggregate surfaces and biopore walls were prepared from Bt horizons of Luvisols developed from Loess and glacial till. The mm-scale spatial distribution of OM composition was scanned using diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The ratio between alkyl and carboxyl functional groups in OM was used as potential wettability index (PWI) of the OM. The infiltration dynamics of water and ethanol droplets were determined measuring contact angles (CA) and water drop penetration times (WDPT). At intact surfaces of earthworm burrows and coated cracks of the Loess-Bt, the potential wettability of the OM was significantly reduced compared to the uncoated matrix. These data corresponded to increased WDPT, indicating a mm-scaled sub-critical water repellency. The relation was highly linear for earthworm burrows and crack coatings from the Loess-Bt with WDPT >2.5 s. Other surfaces of the Loess-Bt and most surfaces of the till-derived Bt were not found to be repellent. At these surfaces, no relations between the potential wettability of the OM and the actual wettability of the surface were found. The results suggest that water absorption at intact surface structures, i.e., mass exchange between PF paths and soil matrix, can be locally affected by a mm-scale OM distribution if OM is of increased content and is enriched in alkyl functional groups. For such surfaces, the relation between potential and actual wettability provides the possibility to evaluate the mm-scale spatial distribution of wettability and sorption and mass exchange from DRIFT spectroscopic scanning.}, language = {en} } @article{HeinrichBalanzateguiBensetal.2018, author = {Heinrich, Ingo and Balanzategui, Daniel and Bens, Oliver and Blasch, Gerald and Blume, Theresa and Boettcher, Falk and Borg, Erik and Brademann, Brian and Brauer, Achim and Conrad, Christopher and Dietze, Elisabeth and Dr{\"a}ger, Nadine and Fiener, Peter and Gerke, Horst H. and G{\"u}ntner, Andreas and Heine, Iris and Helle, Gerhard and Herbrich, Marcus and Harfenmeister, Katharina and Heussner, Karl-Uwe and Hohmann, Christian and Itzerott, Sibylle and Jurasinski, Gerald and Kaiser, Knut and Kappler, Christoph and Koebsch, Franziska and Liebner, Susanne and Lischeid, Gunnar and Merz, Bruno and Missling, Klaus Dieter and Morgner, Markus and Pinkerneil, Sylvia and Plessen, Birgit and Raab, Thomas and Ruhtz, Thomas and Sachs, Torsten and Sommer, Michael and Spengler, Daniel and Stender, Vivien and St{\"u}ve, Peter and Wilken, Florian}, title = {Interdisciplinary Geo-ecological Research across Time Scales in the Northeast German Lowland Observatory (TERENO-NE)}, series = {Vadose zone journal}, volume = {17}, journal = {Vadose zone journal}, number = {1}, publisher = {Soil Science Society of America}, address = {Madison}, issn = {1539-1663}, doi = {10.2136/vzj2018.06.0116}, pages = {25}, year = {2018}, abstract = {The Northeast German Lowland Observatory (TERENO-NE) was established to investigate the regional impact of climate and land use change. TERENO-NE focuses on the Northeast German lowlands, for which a high vulnerability has been determined due to increasing temperatures and decreasing amounts of precipitation projected for the coming decades. To facilitate in-depth evaluations of the effects of climate and land use changes and to separate the effects of natural and anthropogenic drivers in the region, six sites were chosen for comprehensive monitoring. In addition, at selected sites, geoarchives were used to substantially extend the instrumental records back in time. It is this combination of diverse disciplines working across different time scales that makes the observatory TERENO-NE a unique observation platform. We provide information about the general characteristics of the observatory and its six monitoring sites and present examples of interdisciplinary research activities at some of these sites. We also illustrate how monitoring improves process understanding, how remote sensing techniques are fine-tuned by the most comprehensive ground-truthing site DEMMIN, how soil erosion dynamics have evolved, how greenhouse gas monitoring of rewetted peatlands can reveal unexpected mechanisms, and how proxy data provides a long-term perspective of current ongoing changes.}, language = {en} } @article{MuellervanSchaikBlumeetal.2014, author = {M{\"u}ller, Eva Nora and van Schaik, Loes and Blume, Theresa and Bronstert, Axel and Carus, Jana and Fleckenstein, Jan H. and Fohrer, Nicola and Geissler, Katja and Gerke, Horst H. and Gr{\"a}ff, Thomas and Hesse, Cornelia and Hildebrandt, Anke and H{\"o}lker, Franz and Hunke, Philip and K{\"o}rner, Katrin and Lewandowski, J{\"o}rg and Lohmann, Dirk and Meinikmann, Karin and Schibalski, Anett and Schmalz, Britta and Schr{\"o}der-Esselbach, Boris and Tietjen, Britta}, title = {Scales, key aspects, feedbacks and challenges of ecohydrological research in Germany}, series = {Hydrologie und Wasserbewirtschaftung}, volume = {58}, journal = {Hydrologie und Wasserbewirtschaftung}, number = {4}, publisher = {Bundesanst. f{\"u}r Gew{\"a}sserkunde}, address = {Koblenz}, issn = {1439-1783}, doi = {10.5675/HyWa_2014,4_2}, pages = {221 -- 240}, year = {2014}, abstract = {Ecohydrology analyses the interactions of biotic and abiotic aspects of our ecosystems and landscapes. It is a highly diverse discipline in terms of its thematic and methodical research foci. This article gives an overview of current German ecohydrological research approaches within plant-animal-soil-systems, meso-scale catchments and their river networks, lake systems, coastal areas and tidal rivers. It discusses their relevant spatial and temporal process scales and different types of interactions and feedback dynamics between hydrological and biotic processes and patterns. The following topics are considered key challenges: innovative analysis of the interdisciplinary scale continuum, development of dynamically coupled model systems, integrated monitoring of coupled processes at the interface and transition from basic to applied ecohydrological science to develop sustainable water and land resource management strategies under regional and global change.}, language = {de} } @article{PremkeAttermeyerAugustinetal.2016, author = {Premke, Katrin and Attermeyer, Katrin and Augustin, J{\"u}rgen and Cabezas, Alvaro and Casper, Peter and Deumlich, Detlef and Gelbrecht, J{\"o}rg and Gerke, Horst H. and Gessler, Arthur and Großart, Hans-Peter and Hilt, Sabine and Hupfer, Michael and Kalettka, Thomas and Kayler, Zachary and Lischeid, Gunnar and Sommer, Michael and Zak, Dominik}, title = {The importance of landscape diversity for carbon fluxes at the landscape level: small-scale heterogeneity matters}, series = {Wiley Interdisciplinary Reviews : Water}, volume = {3}, journal = {Wiley Interdisciplinary Reviews : Water}, publisher = {Wiley}, address = {Hoboken}, issn = {2049-1948}, doi = {10.1002/wat2.1147}, pages = {601 -- 617}, year = {2016}, abstract = {Landscapes can be viewed as spatially heterogeneous areas encompassing terrestrial and aquatic domains. To date, most landscape carbon (C) fluxes have been estimated by accounting for terrestrial ecosystems, while aquatic ecosystems have been largely neglected. However, a robust assessment of C fluxes on the landscape scale requires the estimation of fluxes within and between both landscape components. Here, we compiled data from the literature on C fluxes across the air-water interface from various landscape components. We simulated C emissions and uptake for five different scenarios which represent a gradient of increasing spatial heterogeneity within a temperate young moraine landscape: (I) a homogeneous landscape with only cropland and large lakes; (II) separation of the terrestrial domain into cropland and forest; (III) further separation into cropland, forest, and grassland; (IV) additional division of the aquatic area into large lakes and peatlands; and (V) further separation of the aquatic area into large lakes, peatlands, running waters, and small water bodies These simulations suggest that C fluxes at the landscape scale might depend on spatial heterogeneity and landscape diversity, among other factors. When we consider spatial heterogeneity and diversity alone, small inland waters appear to play a pivotal and previously underestimated role in landscape greenhouse gas emissions that may be regarded as C hot spots. Approaches focusing on the landscape scale will also enable improved projections of ecosystems' responses to perturbations, e.g., due to global change and anthropogenic activities, and evaluations of the specific role individual landscape components play in regional C fluxes. WIREs Water 2016, 3:601-617. doi: 10.1002/wat2.1147}, language = {en} }