https://news.oregonstate.edu/news/nitrogen-fixing-trees-“eat”-rocks-play-pivotal-role-forest-health
This article is for red alder but green is common here and does the same thing. We use it a ton in reclamation, as it eventually gets thinned out by tree species which grow taller.
Alder is hyper competitive, builds soil and tough as nails which makes it a great pioneer species