Ecological aspects of arbuscular mycorrhizal fungal communities in different habitat types of a Brazilian mountainous area

Increasing elevation affects many abiotic factors, such as a temperature decrease and an increase in radiation, as well as multiple biotic characteristics such as richness and composition of plant communities, both of which contribute to the formation of different habitats in mountainous landscapes. Both biotic and abiotic factors also affect belowground arbuscular mycorrhizal fungi (AMF) communities, but there is scarce information available from tropical mountain ecosystems. The objective of this study was to determine the diversity and distribution of AM fungi in different mountainous habitat types in the Chapada Diamantina mountain range in Bahia (NE Brazil). Soil samples were collected in five habitats types: high-altitude cerrado savannas (HAC), natural grasslands (GRA), gallery forests (GAF), in natural rocky rupestrian fields (shrublands; CAR) and in rocky, rupestrian field in the regeneration stage (CRR). A total of 49 AMF species were identified, of which Glomeraceae and Acaulosporaceae species were the most representative families. The AMF communities did not follow the shifts in plant communities. The composition of the AMF communities differed only between CAR and HAC and between CRR and GAF, while the other habitats had similar AMF communities. Our conclusion is that the AMF community assemblages in tropical mountains are related to the heterogeneity of habitats of these ecosystems. In our study, silt and coarse sand contents were the main factors related to the community composition of AMF in the different habitats.