Black alder (Alnus glutinosa) is an adaptive and fast-growing deciduous tree that can be found across most of Europe. Due to its multiple uses in silviculture and in the wood industry, the tree is considered to be an important forest species. The wood of black alder is rather soft, but durable when kept under water, hence its use for underwater constructions and for smaller boats. Ecologically, the tree provides a valuable source of food for wildlife throughout the winter.
Black alder prefers a moderate to cold climate and grows best in deep soils, with a high water level, such as along river banks and in marshes. In these locations, it also contributes to flood control and the stabilization of riverbanks.
Due to its capability to fix nitrogen, the black alder is a valuable pioneer species with the ability to improve soil conditions for other plants and thereby minimize the need for nitrogen fertilizers. However, the tree is light-demanding and is eventually unable to withstand competition from new and neighboring trees.