Landscape experiments of fluvial environments such as rivers and deltas are often conducted with live seedlings to investigate effects of biogeomorphological interactions on morphology and stratigraphy. However, such experiments have been limited to a single species, usually alfalfa (Medicago sativa), whereas important environments in nature have many different vegetation types and eco‐engineering effects. Landscape experimentation would therefore benefit from a larger choice of tested plant species. For the purpose of experimental design our objective was to identify fast‐germinating and fast‐growing species and determine their sensitivity to flow conditions during and after settling, their maximum growth, hydraulic resistance and added bank strength. We tested germination time and seedling growth rate of 18 candidate species with readily available seeds that are fast growing and occur at waterlines, plus Medicago sativa as a control. We selected five species that germinate and develop within days and measured properties and eco‐engineering effects depending on plant age and density, targeting typical experimental conditions of 0–0.3 m/s flow velocity and 0–30 mm water depth. Tested eco‐engineering effects include bank strength and flow resistance. We found that Rumex hydrolapathum can represent riparian trees. The much smaller Veronica beccabunga and Lotus pedunculatus can represent grass and saltmarsh species as they grow in dense patches with high flow resistance but are readily erodible. Sorghum bicolor grows into tall, straight shoots, which add significantly to bank strength, but adds little flow resistance and may represent sparse hardwood trees. Medicago sativa also grows densely under water, suggesting a use for mangroves and perhaps peat. In stronger and deeper flows the application of all species changes accordingly. These species can now be used in a range of landscape experiments to investigate combined effects on living landscape patterns and possible facilitation between species. The testing and treatment methodology can be applied to new species and other laboratory conditions. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd. © 2019 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd © 2019 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd.

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<p>Knowledge about the nexus between litter decomposition and soil organic matter formation is still scarce, likely because litter decomposition studies are often conducted in the absence of mineral soil. Even if mineral soil is considered, variations in soil texture, which should substantially influence decomposition and soil C sequestration via, e.g., different capacities to store C or host microbial communities, have been neglected. Here, we examined the effect of soil texture on litter decomposition and soil organic matter formation by incubating sand- and clay-rich soils. These soils, taken under C3 vegetation, were amended with C4 litter to trace the fate of organic matter newly entering the soil. While we found only small amounts of litter-derived carbon (C) in the mineral soils after our six-month experiment, the microbial activity and amount of remaining litter between the sand- and clay-rich soils substantially differed. A high microbial activity combined with higher amounts of litter-derived C and a higher remaining litter mass in the clay-rich soil indicate a more effective transformation of litter to soil organic matter as compared to the sand-rich soil. In the sand-rich soil, microbial activity was lower, less soil C was litter-derived, and the litter lost more of its mass. We explain the apparently contradictory results of higher microbial activity and concurrently higher C contents with a more effective microbial pathway of SOM formation in the clay-rich soil. Our results indicate that soil texture does not only play a role in the provision of reactive surfaces for the stabilization of C but will also affect the decomposition of litter via effects on microbial activity, ultimately determining if litter C is transferred to the soil or respired to the atmosphere.</p>