My PhD is part of the project DynaCom (Spatial community ecology in highly dynamic landscapes: from island biogeography to metaecosystems) funded by the German Research Foundation. My focus is to understand the spatial distribution of the plant-fungus interaction in salt marshes in northern Germany. We hypothesize that the symbiosis between plant and fungi in salt marshes can increase probability of colonization of both partners (symbiosis as dispersal trait), persistence in the habitat (symbiosis as feeding trait) and the ability to tolerate changing environmental conditions (symbiosis as tolerance trait). For this purpose, traits such as plant or fungal partner, cell size and genome size will be determined for a number of halophytes of different ploidy levels and two main groups of fungi will be targeted: mycorrhizae and the dark septate endophytes (DSE).