Black alder

Description:

The common alder provides food and shelter to wildlife, with a number of insects, lichens and fungi being completely dependent on the tree. It is a pioneer species, colonizing vacant land and forming mixed forests as other trees appear in its wake.

Habitat:

Near river.

Notes:

The common alder is most noted for its symbiotic relationship with the bacterium Frankia alni, which forms nodules on the tree's roots. This bacterium absorbs nitrogen from the air and fixes it in a form available to the tree. In return, the bacterium receives carbon products produced by the tree through photosynthesis.