Contribution of Suillus variegatus to the ecological restoration of 10-year-old Pinus tabuliformis on the Loess Plateau

Abstract

Ectomycorrhizal (ECM) fungi form symbioses with many terrestrial plant species and are important for the water and nutrient absorption required for the growth of Pinus tabuliformis seedlings. The ECM fungal community influences many important ecosystem processes. However, the effect of artificially applying these fungi to P. tabuliformis in the field has rarely been studied over a long period of time. Here, we inoculated ten-year-old P. tabuliformis with Suillus variegatus on the Loess Plateau and conducted a three-year observation. After measuring the growth indices of P. tabuliformis, the properties of the rhizosphere soil, and the diversity of the rhizosphere soil fungal communities, we found that S. variegatus increased soil nitrate-nitrogen (NN) and available phosphorus (AP) contents. The height of new buds, chlorophyll content, and viability of P. tabuliformis significantly improved with the addition of ECM fungi. At the same time, inoculation with ECM fungi significantly increased the soil fungal diversity in the rhizosphere of P. tabuliformis. Taken together, the results suggest that ECM fungi play an important role in the ecological restoration of the Loess Plateau and can be manually applied to forestlands to increase ten-year-old P. tabuliformis survival as well as local soil fungal diversity.