Factsheet S02: Alder – Alnus glutinosa
The alder is a deciduous tree of conical habit, usually growing to about 50 ft (15 m), exceptionally to 85 ft (25 m). Its natural range is throughout Europe to Siberia, to western Asia and north Africa; it is found in throughout Britain up to an altitude of 1600 ft (500 m). Alders naturally grow wherever the soil is predominantly damp, by rivers and streamsides, marsh areas etc and quickly colonise damp sites. It is a light-demanding pioneer tree which is usually followed by later successional species; it frequently occurs in mixtues with ash, hazel and birches.