Gray Alder is a small, flood-tolerant, deciduous tree. It is monoecious (separate male and female flowers bloom on the same plant). Both flowers are purple-red catkins; the female flower is followed by a woody, cone-like structure containing the seeds. Birds, such as redpolls, siskins, chickadees, and goldfinches, feed on the seeds. This tree grows fast, but is short-lived, usually not lasting beyond 40 years. It prefers moist to wet soils and is flood-tolerant. Alder is a nitrogen-fixing species, adding nutrients to the soil. For these reasons, Gray Alder is planted as a pioneer species for revegetating disturbed areas along streams or ponds. It can also be massed for a windbreak or used for erosion control.