Abstract

Caatinga is characterised as being a unique semi-arid biome only found in Brazil. It is characterised mainly for its soil poor in mineral and organic nutrients, and low water activity. On the other hand, Atlantic Forest is mainly characterised by its nutrient-rich soil, and its high water activity. Fungi are important constituents of both biomes. Among the fungi frequently isolated from soil of both Caatinga and Atlantic Forest, species of Penicillium are prominent. The richness, abundance, evenness, and dominance of species of Penicillium in soils of the Caatinga and Atlantic Forest areas in Pernambuco, Brazil, were analyzed. The influence of seasonality (rainy and dry seasons) on the communities of species of Penicillium in each biome and their distribution was assessed. A total of 815 Penicillium isolates was found. From this total amount, 370 isolates were found in the Caatinga soil, whereas 445 were found in the Atlantic Forest soil. Thirty-one species were morphologically identified, with 23 of them in the Caatinga soil and 17 in the Atlantic Forest soil. In addition, three isolates from Caatinga soil were only identified to genus. The present study revealed that soils from Caatinga and Atlantic Forest have a high diversity of species of Penicillium, with the Caatinga presenting rare species. Furthermore, the communities of Penicillium species are very different, but well distributed in each biome. In the dry season, there was greater species richness in areas of the two biomes, indicating that the species may be well adapted to low soil water availability for the development and maintenance of balanced communities.