INTERFACE working package A
Plants & Sedimentby Stefanie Nolte |
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Effects of salt-marsh management on hydrology, plant-species richness
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In work package A of the INTERFACE project, we aim at investigating the effects of salt-marsh management on marsh hydrology, the spread of Elymus athericus, the plant-species richness and sediment dynamics. As a baseline, we start to compare the morphology of marshes which established spontaneously with those that are the result of human interference and contain straight ditches. This will be done using aerial photographs of the entire German Wadden Sea coast. We expect natural marshes to have a lower creek density that will strongly affect marsh hydrology. To investigate marsh hydrology in more detail, we will select one site to study the effects of creek morphology (natural vs. anthropogenic) and one site to study the effect of grazing on various factors, e.g. soil moisture and redox potential. These factors will also be linked to c-sequestration and decomposition in part B . The expected differences in hydrology in turn are likely to affect the spread of E. athericus. This plant outcompetes most other salt marsh plants in the high marsh and only occurs if the soil is not too wet. Therefore, we expect marsh hydrology in combination with topography to furthermore influence plant species richness. Finally, the question of how grazing influences sediment deposition patterns will be studied within two sites. Grazing is expected to influence sediment deposition by reducing the vegetation height and density. However, tall and dense vegetation was found to have a positive effect on sediment deposition rates and we would therefore expect grazing to reduce sediment deposition. Additionally, grazing is hypothesized to decrease accretion rates, because trampling leads to soil compaction and thereby directly reduces accretion rates. In four different studies we are aiming to answer the following questions:
A.1 Morphology
A.2 Hydrology
A.3 Vegetation
A.4 Sediment
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