Mediterranean-Climate Stream ecosystems (MCS) are shaped by seasonally predictable events of flooding and drying, both can destroy habitat patches and create new ones that are then colonized by the biota. Therefore, these ecosystems can be regarded as being under a continuous cycle of destruction (autumn/winter) and re-growth (spring/summer). We used the unique hydrological pattern of MCS for testing the structuring role of in-stream vegetation as ‘landscape modulators’. In fluvial systems macrophytic vegetation can modify resources (e.g. flow and habitat heterogeneity), with cascading impacts on biotic structure. We followed patch formation, assessed its role in modifying resources and ultimately evaluated the effect on macroinvertebrate community. We conclude that additional work is needed in order to better understand the contribution of EE in the early stages of ecosystem development, such as Mediterranean ones.