Communities of arbuscular mycorrhizal fungi in coffee plantations at “̈Mata Atlantica” domain

Abstract

The objective of this study was to relate coffee productivity to the density and diversity of native AMF (arbuscular mycorrhizal fungi) at different soil depths, as well as to assess the impact of land use change (from forest to coffee plantations) on mycorrhizal communities present in the soil and litter. Regarding different depths (0-20, 20-40, 40-60 cm), soil samples were collected from two plots (with higher and lower productivity but with the same management, soil type, spacing, and variety). Concerning the comparison between forest and coffee, soil and litter samples were collected along transects located in 4 coffee plots and 4 forest fragments in different seasonal periods (dry and wet). Parameters such as soil fertility, spore density, morphological identification, species richness, and Hill numbers were analyzed in both studies, while total soil protein concentrations related to glomalin, both total and easily extractable, and mycorrhizal colonization in the 0-10 cm layer were measured only for the study at different depths. The results indicate that higher diversity and density of species and spores at different depths do not directly correlate with coffee productivity. However, the high concentration of

easily extractable glomalin-related soil protein (EE-GRSP) at all depths and total glomalin (T- GRSP) in the 0-20 cm layer showed a relationship with higher productivity, along with greater

AMF colonization in that area. There were species exclusively found at depths below 20 cm, indicating specific richness in these deeper soil layers. The change from forest to coffee plantations had a significant impact on the AMF community, both in the soil and litter, resulting in a decrease in spore density and species diversity. Seasonality, especially the dry season, favored an increase in spores in the coffee plots, both in the soil and litter, but had no significant impact on the soil and litter in the forest.