Floodplain ecosystems are biodiversity hotspots and supply multiple ecosystem services. At the same time they are often prone to human pressures that increasingly impact their intactness. Multifunctional floodplain management can be defined as a management approach aimed at a balanced supply of multiple ecosystem services that serve the needs of Communicated by Barbara Livoreil. This is part of the special issue on Networking Biodiversity Knowledge. the local residents, but also those of off-site populations that are directly or indirectly impacted by floodplain management and policies. Multifunctional floodplain management has been recently proposed as a key concept to reconcile biodiversity and ecosystem services with the various human pressures and their driving forces. In this paper we present biophysics and management history of floodplains and review recent multifunctional management approaches and evidence for their biodiversity effects for the six European countries Ireland, the Netherlands, Germany, Slovakia, Hungary and the Ukraine. Multifunctional use of floodplains is an increasingly important strategy in some countries, for instance in the Netherlands and Hungary, and management of floodplains goes hand in hand with sustainable economic activities resulting in flood safety and biodiversity conservation. As a result, biodiversity is increasing in some of the areas where multifunctional floodplain management approaches are implemented. We conclude that for efficient use of management resources and ecosystem services, consensual solutions need to be realized and biodiversity needs to be mainstreamed into management activities to maximize ecosystem service provision and potential human benefits. Multifunctionality is more successful where a broad range of stakeholders with diverse expertise and interests are involved in all stages of planning and implementation. Electronic supplementary material

QuestionStudies in the northwest Atlantic have shown that nutrient enrichment can severely impact salt marshes, undermining their broad range of high‐value ecosystem services. However, biogeographical differences in plant communities may preclude extrapolation of these findings to other regions. The few investigations of such impacts elsewhere, including in Europe, have been strongly localised, restricting generalisations, and have not addressed community‐level properties.LocationSouth and east coasts of Ireland (northeast Atlantic).MethodsWe conducted a field survey of vascular plants and soil properties in fifteen salt marshes representing broad environmental gradients but comparable biogeographical settings, to test if salt marsh plant (a) diversity and (b) community composition are related to soil nutrients.ResultsSpecies richness and Shannon diversity were both negatively related to soil NOx−, and Shannon diversity had a hump‐shaped relationship to labile P. Multivariate community composition was highly significantly related to NOx−, to a lesser degree to P, and marginally significantly to NH4+. This was most clearly evident in the positive association of the ground cover of an evergreen dwarf shrub, Atriplex portulacoides, and a weaker negative association of a forb, Plantago maritima, with NOx−, indicating competition between these key and functionally contrasting mid‐salt‐marsh species. The relationship between community composition and P was most evident through the positive association of P with the invasive cordgrass, Spartina anglica.ConclusionsPhysiognomic and functional differences between the herb‐rich Pl. maritima community and monospecific A. portulacoides stands likely have implications for ecosystem services, as would a continued expansion of S. anglica. Further studies to ascertain causality could determine whether such transitions can be driven by nutrient enrichment.