Ilsterner Au floodplain forest Biotopes are fragile natural habitats which require careful protection. The floodplain forest near Ilistra/Ilstern is the most important biotope in the lower Pusteria/Pustertal valley. Ash trees are the predominant plants in the eastern part of this biotope, which is a bustling home to many different animals. Countless fascinating insects and birds live here all year round, and many migratory birds can be observed on their way north or south. The ecological function of a floodplain forest however is not limited to merely protecting its native wildlife: Biotopes also play a key role in maintaining the hydrological balance of their surroundings, since they act as a large water reservoir. But they are also a precious and still untouched counterpart to the surrounding landscapes which civilisation uses intensively. Floodplain forests are rich in water and plant nutrients, which provide an ideal setting for a colourful range of vegetation. While grey alders are the most common trees to be found in the Ilsterner Au floodplain forest, parts of it are also densely populated by spruces and pine trees – a phenomenon which suggests that the groundwater levels have dropped and that the biotope is no longer regularly flooded. There are a number of measures which could improve this precarious hydrological balance: One suggestion for example aims at turning the area into an official nature reserve.