Alnus rubra
"Alnus rubra" is an important early colonizer of disturbed forests and riparian areas mainly because of its ability to fix nitrogen in the soil. This self-fertilizing trait allows red alder to grow rapidly, and makes it effective in covering disturbed and/or degraded land, such as mine spoils. Alder leaves, shed in the fall, decay readily to form a nitrogen-enriched humus. Red alder is occasionally used as a rotation crop to discourage the conifer root pathogen "Phellinus weirii" (Laminated root rot).