Diversidade e biogeografia de fungos no solo sob a projeção da copa de espécies arbóreas da Mata Atlântica / Diversity and biogeography of fungi in soil under the canopy of tree species in the Atlantic Forest

AUTOR(ES)
DATA DE PUBLICAÇÃO

2011

RESUMO

The community structure and diversity of fungi in soil under the canopy of four tree species (Ocotea dispersa, Ocotea teleiandra, Tabebuia serratifolia, and Mollinedia schottiana), in the Carlos Botelho State Park (PECB) were examined in two different seasons, using PCR-DGGE and rDNA ITS region clone library sequencing. The relationships between fungal community structures, concentration of microbial biomass carbon (MBC), soil chemical properties, and different fractions of soil organic matter (SOM) were evaluated using redundance analysis. The pH, OM, C, Ca, Al, and V% showed significant differences in soil under the canopy of different species of trees. The highest values of pH, OM, C, Ca, and V% were observed under the O. dispersa canopy, while the highest concentrations of Al were observed in the soil under the O. teleiandra canopy. The concentration of humic acid (HA) was significantly higher in soil under the canopy of O. dispersa. The concentration of MBC was higher in the low rain precipitation season, regardless of plant species. The fungal community structures observed in soil under the canopies of the studied tree species were distinct in each soil microenvironment. The fungal community structures also showed variation with the variation in rain precipitation. The estimated OTU richness based on the sequencing of clones of the rDNA ITS region was significantly different between samples. Based on the Shannon diversity index, the fungal diversity in soil under the canopy of Ocotea dispersa was higher than in soil under the canopy of other tree species. The phylogenetic affiliation of OTUs showed the occurrence of phyla Basidiomycota, Zygomycota, Ascomycota, Chytridiomycota and Glomeromycota, in order of abundance, and non-cultivated fungi that comprised 25% of the analyzed sequences. OTUs related to the phylum Basidiomycota were more abundant in soil under the canopies of all studied tree species (67% in MS, 59% in OT, 66% in TS and 57% in OD). In this phylum, OTUs affiliated to Cryptococcus podzolicus and Trichosporon sporotrichoides were the most abundant. From Zygomycota, OTUs affiliated to the genus Mortierella were more abundant. It can be concluded that the fungal diversity and community structure in the soil depends on the plant species growing in it, and may be associated with the concentration of organic matter, nitrogen, and base saturation.

ASSUNTO(S)

atlantic forest biodiversidade biodiversity biogeografia biogeography fungi fungos mata atlântica matéria orgânica do solo microbiologia do solo. soil microbiology. soil organic matter

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