500 ISSN 1067-4136, Russian Journal of Ecology, 2018, Vol. 49, No. 6, pp. 500–506. © Pleiades Publishing, Ltd., 2018. Funneliformis mosseae and Invasion by Exotic Legumes in a Brazilian Tropical Seasonal Dry Forest 1 Tancredo Augusto Feitosa de Souza a, *, Susana Rodriguez-Echeverria b, **, Helena Freitas b, ***, Leonaldo Alves de Andrade c, ****, and Djail Santos a a Agrarian Science Center, Department of Soils and Rural Engineering, Federal University of Paraíba, Paraíba, Areia, 58397-000 Brazil b Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, 3000-456 Portugal c Agrarian Science Center, Department of Soils and Rural Engineering, Federal University of Paraíba, Paraíba, Areia, 58397-000 Brazil *e-mail: tancredo_agro@hotmail.com **e-mail: susanar@ci.uc.pt ***e-mail: hfreita@ci.uc.pt ****e-mail: landrade@cca.ufpb.br Received March 1, 2017 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 eco- system 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 cos- mopolitan 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 rhizo- sphere 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 biolog- ical invasion process of the Brazilian tropical seasonal dry forest by P. aculeata and P. juliflora and (b) F. mos- seae might be an important AMF species during the biological invasion process. Keywords: AMF inoculation, biological invasion, drylands, legumes, Glomeromycota, Funneliformis mosseae DOI: 10.1134/S1067413618060127 INTRODUCTION Exotic plant species often change the overall diver- sity of the plant community invaded [1], but they can also affect belowground soil communities [2]. In fact, invasive plant species can alter soil biota in ways that pro- mote the invasion, for example by associating with soil mutualists that clearly facilitate some invasions [3]. Arbuscular mycorrhizal fungi (AMF) are obligate symbionts that exchange nutrients for carbon from host plants [4]. This symbiosis occurs in over 80% of plant species [5] and is crucial for plant nutrient uptake and defense, although the interaction between AMF and plants can range from mutualistic to harm- ful depending on the species and context [6]. The role of AMF during the invasion by exotic plant species has been studied mainly for annual plants. There is less infor- mation about the role of AMF in the invasion by woody plants, although some invasive trees and shrubs can establish symbiosis with AMF in the invaded areas [7]. Funneliformis mosseae (Nicol. and Gerd.) Gerd. and Trappe is probably the most common AMF reported in the scientific literature. It is a cosmopoli- tan fungus that associates with a great number of plant species and is highly resistant to soil disturbances [8]. F. mosseae has been used extensively in inoculation experiments due to its high ability for root coloniza- tion and sporulation [9]. This AMF species has been reported from natural and disturbed sites in Brazilian tropical seasonal dry forest, such as Alagoas (agricul- ture areas) [10], Bahia (native vegetation and degraded areas) [11] and Pernambuco (reforestation areas) [12]. Also, surveys of AMF associated with exotic plants 1 The article is published in the original.