Alder buckthorn is a robust little tree, and will grow in a city or countryside setting as it is tolerant of pollution.
The leaves are an important food plant of the caterpillar of the Brimstone butterfly. Only this tree and the Common Buckthorn (Rhamnus catharticus) are food plants for the Brimstone butterfly larvae, which is becoming increasingly rare. The pollen is useful for many insects, including bees, and the berries are a winter food source for birds.
Why not add a wild bird feeder to your basket to encourage birds visiting your garden throughout the year.