Fungos micorrízicos arbusculares (Glomeromycota) em diferentes fitofisionomias na Chapada do Araripe, Ceará, Brasil

Abstract

Brejos de Altitude are areas of exception or fractions of the perennial tropical rainforest, bringing together both characteristics of the Atlantic Forest and Caatinga biomes, being “islands” of humid forest amid dry vegetation. These environments are usually areas with particular characteristics (vegetation, climate, fauna and soil) different from the environments that surround them. In such environments, little is known about what are the biotic and abiotic factors that are directly related to the modification of the biodiversity of microorganisms present in the soil. Among these, there are the Arbuscular Mycorrhizal Fungi (AMF), which live symbiotically associated with most of the roots of the plants, mainly increasing the absorption of nutrients and facilitating plant growth. These fungi are worldwide and widely studied in several ecosystems, mainly due to their ecological importance for the maintenance of the environment, being distributed in the main terrestrial biomes, in which new species are often known, however the knowledge of the diversity, richness and ecological strategies of these fungi in areas of brejos de altitude it is scarce and requires more research. In this sense, the goal of this work was to compare the diversity of FMA species between different phytophysiognomies of an brejo de altitude, in order to characterize the richness and diversity of FMA in Chapada do Araripe, Ceará, Brazil. The soil samples were collected in April/2019 in the rainy season. Two types of phytophysiognomies were selected: cerradão and humid forest. Spores were quantified and morphologically identified to carry out ecological analyzes of the FMA community. A total of 95 species were recorded, distributed in four orders, 11 families and 17 genera. Some species were detected as indicators of a certain phytophysiognomy. The number of spores was higher in cerradão compared to humid forest, but the richness was higher in humid forest. It was observed that the composition of the FMA communities differed significantly between the phytophysiognomies of Chapada do Araripe. In addition, a significant change was also observed between the FMA community and the chemical parameters of the soil, highlighting the influence of some variables. This work also proposes the morphological description of a new species for the area. The results obtained demonstrate the importance of environments such as brejos de altitude to be studied with their different phytophysiognomies, as for the FMA community and that differences in plant composition, associated with other factors, can provide environmental conditions for the creation of different microhabitats and have influence in the composition, diversity and distribution of FMA communities.