Background Up to 94% of Hungary’s open river floodplains have been lost since the middle of the 19th century. Alluvial forests in the remaining floodplains are under considerable pressure all along the Danube, as well as other rivers in Hungary such as the Tisza, Drava, and Raba. At present, there are very few opportunities to conserve these alluvial forests in an undisturbed condition for the long term. This is in part due to the forest management practices that are widely used on open floodplains. Szabadság Island and the Danube's side-arm in the Lower-Danube region of Hungary have potential for conservation measures in its alluvial habitats. The island is naturally isolated from the surrounding land by the river. This increases its utility as a pilot area for experimental conservation management measures, since the island can be ‘left alone’ after the initial habitat restoration works, and this should allow natural processes to take over on the site. Objectives The DANUBEISLANDFOREST project’s main objective was to demonstrate a long-term, sustainable conservation model for white willow (Salicion albae) alluvial forests in Hungary. A core aim is to eliminate or mitigate the factors that threaten the habitats of Community interest. To achieve these goals, the project consortium intended to clear the project area of invasive species and non-native tree plantations and restore the appropriate water flow in the side-arm to improve water availability for white willow forests during low water periods and to facilitate an undisturbed ecosystem, where natural processes are predominant. Results The DANUBEISLANDFOREST project achieved its main objectives: sustainable conservation of natural alluvial forests on the island and mitigating the threats to these habitats. The 150 m wide side branch of the Danube had been blocked by a rock-fill dam in 1982, splitting up the side-arm into two parts and stopping the natural river flow. This caused the riverbed to silt up. Hence, approximately one third of the width of the side-arm was dredged. In total, two dredging ships removed 160 000 m3 of sediment and deposited it safely into the main channel of the Danube. After relocating two water pipes, the project team was able to open up the rock-fill dam. Thanks to these measures, the side-arm now carries water (depth of 180 cm or more) throughout the year. However, some shallow spots remain, ensuring habitat diversity as well as feeding grounds for birds. By the end of the project in October 2013, rheophilic fish species that prefer running water such as Eudontomyzon mariae, Gobio albipinnatus, and Gymnocephalus schraetser had reappeared in the side-arm. The Black Kite (Milvus migrans) was nesting on the island in 2012 and 2013, and the European beaver also appeared in 2010. The conservation status of the forests on the 47 ha island was significantly improved in terms of structure and future prospects. Commercial forestry had caused considerable degradation of the forest with the creation of hybrid poplar plantations instead of indigenous forest. In addition, non-native tree species such as Fraxinus pennsylvanica and Acer negundo were spreading on the island. In order to prevent future damage due to commercial forestry, the project consortium bought the island, which is now owned by the Hungarian State and managed by the Duna-Drava National Park Directorate. Forest management was changed to “non-profit”, so that its sole purpose now is nature conservation. Invasive species and non-native plantations were cut down. To achieve long-term success, this work needs to be kept up at regular intervals for several years to come, until the canopy of the forest closes. When replacing the non-native species with a semi-natural native softwood gallery forest, the project employed different planting methods, using the traditional technique in one sub-site and one with more densely planted rows in another with the latter being nursed by hand. The consortium found that planting a greater number of saplings was more effective, as it imitates the high number of seeds that softwoods produce. As the saplings compete for light, they grow faster. Although it proved to be more expensive in the first year and nursing required a lot of manual labour, the survival rate of the saplings was much higher and their development faster. The method also stunted the re-growth of invasive saplings, because the canopy closed more quickly. Keeping in mind the importance of environmental education, the project partners also set up the Aquarius Nature Trail along the banks of the river and the island to make the unique wildlife of the area accessible to the public. Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).