The landscape at high altitude in Gastern valley is dominated by the small river Kander making its way newly repeatedly. The result is a typical floodplain landscape: in curves and with numerous flood plain ponds, the river Kander meanders through the valley. Gravel terraces, gravel plains, pioneer plants and young forests along the river are typical elements. In areas that have not been flooded for some time, one encounters real forest. In other places, one can observe how the vegetation begins to recolonize the free areas.
The moving course of Kander changes the landscape constantly: habitats are destroyed while new ones are created. This dynamic creates space for a rich flora and fauna. Here for example the Alpine newt and the mountain toad find appropriate waters for reproduction and for their offspring. In early summer a crowd of tadpoles and larvae jostle in the shallow, calm ponds that arose along the Kander river. The Gastern valley encompasses beside the “Gasternholz” two other wetlands of national importance: the areas Gastere near Selden and Kanderfirn.