Hippophae rhamnoides
"Hippophae rhamnoides" plants that are 1–2 years old develop root nodules containing actinobacteria of the genus "Frankia", which are capable of fixing nitrogen. As a result of this relationship, the soils in stands of "H. rhamnoides" are enriched in nitrogen. The nitrogen-fixing activity of the symbiotic bacteria is not constant, but depends on external factors such as the climate or whether additional nitrogen fertilization occurred.