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A Molecular Survey of the Diversity of Microbial Communities in Different Amazonian Agricultural Model Systems
Cell and Molecular Biology Laboratory, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário-303, CEP. 13.416-000, Piracicaba, SP, Brazil
These authors share first authorship.
* Author to whom correspondence should be addressed.
Received: 26 March 2010; in revised form: 11 May 2010 / Accepted: 12 May 2010 / Published: 19 May 2010
Abstract: The processes of land conversion and agricultural intensification are a significant cause of biodiversity loss, with consequent negative effects both on the environment and the sustainability of food production.The anthrosols associated with pre-Colombian settlements in the Amazonian region are examples of how anthropogenic activities may sustain the native populations against harsh tropical environments for human establishment, even without a previous intentionality of anthropic soil formation. In a case study (Model I—“Slash-and-Burn”) the community structures detected by automated ribosomal intergenic spacer analysis (ARISA) revealed that soil archaeal, bacterial and fungal communities are heterogeneous and each capable of responding differently to environmental characteristics. ARISA data evidenced considerable difference in structure existing between microbial communities in forest and agricultural soils. In a second study (Model II—“Anthropogenic Soil”), the bacterial community structures revealed by terminal restriction fragment length polymorphism (T-RFLP) differed among an Amazonian Dark Earth (ADE), black carbon (BC) and its adjacent non-anthropogenic oxisoil. The bacterial 16S rRNA gene (OTU) richness estimated by pyrosequencing was higher in ADE than BC. The most abundant bacterial phyla in ADE soils and BC were Proteobacteria—24% ADE, 15% BC; Acidobacteria—10% ADE, 21% BC; Actinobacteria—7% ADE, 12% BC; Verrucomicrobia, 8% ADE; 9% BC; Firmicutes—3% ADE, 8% BC. Overall, unclassified bacteria corresponded to 36% ADE, and 26% BC. Regardless of current land uses, our data suggest that soil microbial community structures may be strongly influenced by the historical soil management and that anthrosols in Amazonia, of anthropogenic origins, in addition to their capacity of enhancing crop yields, may also improve microbial diversity, with the support of the black carbon, which may sustain a particular and unique habitat for the microbes.
Keywords: microbial diversity; slash-and-burn agriculture; land use systems; Amazonian Dark Earth; Terra Preta de Índio; black carbon
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Cite This Article
MDPI and ACS Style
Navarrete, A.A.; Cannavan, F.S.; Taketani, R.G.; Tsai, S.M. A Molecular Survey of the Diversity of Microbial Communities in Different Amazonian Agricultural Model Systems. Diversity 2010, 2, 787-809.
Navarrete AA, Cannavan FS, Taketani RG, Tsai SM. A Molecular Survey of the Diversity of Microbial Communities in Different Amazonian Agricultural Model Systems. Diversity. 2010; 2(5):787-809.
Navarrete, Acácio A.; Cannavan, Fabiana S.; Taketani, Rodrigo G.; Tsai, Siu M. 2010. "A Molecular Survey of the Diversity of Microbial Communities in Different Amazonian Agricultural Model Systems." Diversity 2, no. 5: 787-809.