Alnus glutinosa

Tracheophyta MagnoliopsidaBetulaceaeAlnusAlnus glutinosa


A deciduous tree of damp or wet, basic to moderately acidic soils, found beside rivers, streams, canals, lakes and ditches, and in flood plains, fens and bogs, carr and wooded dune-slacks. It can rapidly seed into open sites, producing even-aged stands of mature trees, but seedlings are very shade- and drought-sensitive, so regeneration in woodland is often poor. It is also widely planted. 0-470 m (Garrigill, Cumberland).



World Distribution

Eurosiberian Temperate element.

© S. Hammonds

Broad Habitats

Light (Ellenberg): 5

Moisture (Ellenberg): 8

Reaction (Ellenberg): 6

Nitrogen (Ellenberg): 6

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 3.5

July Mean Temperature (Celsius): 14.5

Annual Precipitation (mm): 1100

Height (cm): 2000

Perennation - primary


Life Form - primary

Mega-, meso- and microphanerophyte



Clonality - primary

Little or no vegetative spread

Count of 10km squares in Great Britain: 2478

Count of 10km squares in Ireland: 901

Count of 10km squares in the Channel Isles: 10

Atlas Change Index: -0.32

Weighted Changed Factor: 16

Weighted Change Factor Confidence (90%)


JNCC Designations


Atlas text references

Atlas (184d)
Everett S
1999.  Alder death cause revealed. British Wildlife. 10:365.
Grime JP, Hodgson JG, Hunt R
1988.  Comparative Plant Ecology.
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jalas & Suominen (1976)
McVean (1953
Meusel H, Jäger E, Weinert E
1965.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.