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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

BACTERIA DIVERSITY AND MICROBIAL BIOMASS IN FOREST, PASTURE AND FALLOW SOILS IN THE SOUTHWESTERN AMAZON BASIN

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Autor(es):
Cenciani, Karina [1] ; Lambais, Marcio Rodrigues [2] ; Cerri, Carlos Clemente [3] ; Basilio de Azevedo, Lucas Carvalho [4] ; Feigl, Brigitte Josefine
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] USP, ESALQ, Programa Posgrad Microbiol Agr, BR-13418900 Piracicaba, SP - Brazil
[2] USP, ESALQ, Dept Solos & Nutr Mineral Plantas, BR-13418900 Piracicaba, SP - Brazil
[3] USP, Lab Biogeoquim Ambiental, CENA, BR-13400970 Piracicaba, SP - Brazil
[4] USP, ESALQ, Programa Posgrad Solos & Nutr Mineral Plantas, BR-13418900 Piracicaba, SP - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Revista Brasileira de Ciência do Solo; v. 33, n. 4, p. 907-916, JUL-AUG 2009.
Citações Web of Science: 26
Resumo

It is well-known that Amazon tropical forest soils contain high microbial biodiversity. However, anthropogenic actions of slash and burn, mainly for pasture establishment, induce profound changes in the well-balanced biogeochemical cycles. After a few years the grass yield usually declines, the pasture is abandoned and is transformed into a secondary vegetation called ``capoeira{''} or fallow. The aim of this study was to examine how the clearing of Amazon rainforest for pasture affects: (1) the diversity of the Bacteria domain evaluated by Polymerase Chain Reaction and Denaturing Gradient Gel Electrophoresis (PCR-DGGE), (2) microbial biomass and some soil chemical properties (pH, moisture, P, K, Ca, Mg, Al, H + Al, and BS), and (3) the influence of environmental variables on the genetic structure of bacterial community. In the pasture soil, total carbon (C) was between 30 to 42 % higher than in the fallow, and almost 47 % higher than in the forest soil over a year. The same pattern was observed for N. Microbial biomass in the pasture was about 38 and 26 % higher than at fallow and forest sites, respectively, in the rainy season. DGGE profiling revealed a lower number of bands per area in the dry season, but differences in the structure of bacterial communities among sites were better defined than in the wet season. The bacterial DNA fingerprints in the forest were stronger related to Al content and the Cmic:Ctot and Nmic:Ntot ratios. For pasture and fallow sites, the structure of the Bacteria domain was more associated with pH, sum of bases, moisture, total C and N and the microbial biomass. In general microbial biomass in the soils was influenced by total C and N, which were associated with the Bacteria domain, since the bacterial community is a component and active fraction of the microbial biomass. Results show that the genetic composition of bacterial communities in Amazonian soils changed along the sequence forest-pasture-fallow. (AU)

Processo FAPESP: 04/12689-4 - Diversidade bacteriana em solos da amazonia: variabilidade dos generos associados aos processos de transformacao do nitrogenio.
Beneficiário:Brigitte Josefine Feigl
Linha de fomento: Auxílio à Pesquisa - Regular