Funneliformis mosseae and Invasion by Exotic Legumes in a Brazilian Tropical Seasonal Dry Forest

Abstract

Parkinsonia aculeata and Prosopis juliflora are two of the most problematic invasive plant species in the Brazilian tropical seasonal dry forest, but the mechanisms driving the biological invasion of this ecosystem is virtually unknown. This study assessed the role of arbuscular mycorrhizal symbiosis, in particular of Funneliformis mosseae, on the biological invasion process by P. aculeata and P. juliflora. F. mosseae is a cosmopolitan arbuscular mycorrhizal fungus (AMF) frequently found in association with plants of different regions of the world. The present study was conducted to determine if F. mosseae is present in the soils from two invaded areas by P. aculeata and P. juliflora and to evaluate its contribution to the growth of these invasive plant species. Firstly, AMF colonization and AMF spore abundance was assessed in the roots and rhizosphere of both species in the field. Spores of F. mosseae were obtained from the soil samples and used to set up a greenhouse experiment to evaluate its effect on plant dry biomass and plant phosphorus concentration for both exotic plant species. We found that F. mosseae inoculation promoted the growth of the invaders and lead to a higher P concentration. Our results demonstrate that (a) AMF play an important role in the biological invasion process of the Brazilian tropical seasonal dry forest by P. aculeata and P. juliflora and (b) F. mosseae might be an important AMF species during the biological invasion process.