Arbuscular mycorrhizal fungal communities influence growth and phosphorus concentration of woody plants species from the Atlantic rain forest in South Brazil

Abstract

The influence of arbuscular mycorrhizal fungi (AMF) inoculation on plant growth and phosphorus (P) uptake was studied in seedlings of 8 woody pioneer or late secondary species native to the Atlantic Rain Forest (ARF) that are utilized to recover riparian forests. Inoculum consisted of fungal communities originating from soils classified as a Cambissolo Háplico (CX) and a Neossolo Flúvico (RU). The plant growth experiment design (2 × 3 factorial) consisted of two phosphorus levels (0 and 60 mg P/dm 3 added) and three inoculation treatments (control and inoculation with either RU or CX fungal communities). AMF colonization ranged from 34 to 62% in the pioneer species and was not detected in the late secondary species, except in Cabralea canjerana. Overall, the height, shoot and root biomass, and shoot phosphorus of pioneer species were highly responsive to mycorrhizal inoculation regardless of P addition but such differences were not observed in the late secondary plants. Mycorrhizal plant responses were inversely related to seed mass. Pioneer species were classified as highly to very highly responsive while late secondary species ranged from independent to moderately responsive to mycorrhizas. These results suggest that inoculating seedlings with AMF and supplementing with P should be considered a management strategy, for both pioneer species when revegetating riparian areas or for late secondary species when planting secondary forests for enrichment.