Adaptive growth response of exotic Elaeagnus angustifolia L. to indigenous saline soil and its beneficial effects on the soil system in the Yellow River Delta, China

KEY MESSAGE: Our manuscript showed that Elaeagnus angustifolia L. can be introduced to the Yellow River Delta of China and planting E. angustifolia was beneficial effects on the soil system. The saline soil of the Yellow River Delta of China is not suitable for the growth of crop and afforestation seedlings due to high salt content, high underground water level, and deficiencies in organic matter, nitrogen and phosphorus, which limits urban road greening around the Yellow River Delta. Elaeagnus angustifolia L. (E. angustifolia) is a member of the Elaeagnaceae family, which is a deciduous shrub or small tree. Due to its good resistance, E. angustifolia has been planted widely in the western region of China, and it has been used for wind breaking, landscaping and sand stabilization. Furthermore, E. angustifolia seedlings were introduced to the Yellow River Delta due to its strong stress and adaptive growth response, which were studied in 2014 and 2015. The results revealed that the seedlings of E. angustifolia grew well with high relative growth rates, big crowns, thick basal diameter, thick diameter at the breast height, and many branches, especially during the second year. Planting E. angustifolia on the Yellow River Delta significantly decreased its salt content, and increased its content of organic matter, nitrogen and phosphorus, as well as the number of fungus, bacteria, salt-tolerant bacteria, actinomycetes and salt-tolerant actinomycetes, especially after planting E. angustifolia for two consecutive years. In conclusion, E. angustifolia seedlings can grow well in the saline soil of the Yellow River Delta with a large biomass. In turn, planting E. angustifolia could improve saline soil properties. Hence, E. angustifolia can be a potential local greening tree species.