Scientific names follow Tutin et al. Many of these plants will be found under other scientific names in the horticultural literature, and I hope to eventually include a synonymy. It is cultivated in North America, often under the name of weeping birch. The three trees in my front yard form root sprouts that would take over the bed where they are planted if I didn't cut them back. Birds are also responsible for dispersing the seeds.
Rowans thrive in poor soils and colonize disturbed areas.
In some parts of Europe they are most common around ancient settlements, either because of their weedy nature or because they were planted. They are cultivated in North America, especially in the northeast. Like willows, alders sprout from stumps. This allows them to regenerate after heavy flooding. This species is more common in the mountains of Europe, and is not restricted to moist soils.