TY - JOUR

T1 - Land use intensification in the humid tropics increased both alpha and beta diversity of soil bacteria

AU - Soares de Carvalho, Teotonio

AU - Jesus, Ederson da Conceicao

AU - Barlow, Bernard Josiah

AU - Gardner, Toby Alan

AU - Soares, Isaac Carvalho

AU - Tiedje, James M.

AU - Moreira, Fatima Maria de Souza

N1 - Copyright by the Ecological Society of America, de Carvalho, T. S., Jesus, E. d. C., Barlow, J., Gardner, T. A., Soares, I. C., Tiedje, J. M. and Moreira, F. M. d. S. (2016), Land use intensification in the humid tropics increased both alpha and beta diversity of soil bacteria. Ecology, 97: 2760–2771. doi:10.1002/ecy.1513

PY - 2016/10

Y1 - 2016/10

N2 - Anthropogenic pressures on tropical forests are rapidly intensifying, but our understanding of their implications for biological diversity is still very limited, especially with regard to soil biota, and in particular soil bacterial communities. Here we evaluated bacterial community composition and diversity across a gradient of land use intensity in the eastern Amazon from undisturbed primary forest, through primary forests varyingly disturbed by fire, regenerating secondary forest, pasture, and mechanized agriculture. Soil bacteria were assessed by paired-end Illumina sequencing of 16S rRNA gene fragments (V4 region). The resulting sequences were clustered into operational taxonomic units (OTU) at a 97% similarity threshold. Land use intensification increased the observed bacterial diversity (both OTU richness and community heterogeneity across space) and this effect was strongly associated with changes in soil pH. Moreover, land use intensification and subsequent changes in soil fertility, especially pH, altered the bacterial community composition, with pastures and areas of mechanized agriculture displaying the most contrasting communities in relation to undisturbed primary forest. Together, these results indicate that tropical forest conversion impacts soil bacteria not through loss of diversity, as previously thought, but mainly by imposing marked shifts on bacterial community composition, with unknown yet potentially important implications for ecological functions and services performed by these communities.

AB - Anthropogenic pressures on tropical forests are rapidly intensifying, but our understanding of their implications for biological diversity is still very limited, especially with regard to soil biota, and in particular soil bacterial communities. Here we evaluated bacterial community composition and diversity across a gradient of land use intensity in the eastern Amazon from undisturbed primary forest, through primary forests varyingly disturbed by fire, regenerating secondary forest, pasture, and mechanized agriculture. Soil bacteria were assessed by paired-end Illumina sequencing of 16S rRNA gene fragments (V4 region). The resulting sequences were clustered into operational taxonomic units (OTU) at a 97% similarity threshold. Land use intensification increased the observed bacterial diversity (both OTU richness and community heterogeneity across space) and this effect was strongly associated with changes in soil pH. Moreover, land use intensification and subsequent changes in soil fertility, especially pH, altered the bacterial community composition, with pastures and areas of mechanized agriculture displaying the most contrasting communities in relation to undisturbed primary forest. Together, these results indicate that tropical forest conversion impacts soil bacteria not through loss of diversity, as previously thought, but mainly by imposing marked shifts on bacterial community composition, with unknown yet potentially important implications for ecological functions and services performed by these communities.

U2 - 10.1002/ecy.1513

DO - 10.1002/ecy.1513

M3 - Journal article

VL - 97

SP - 2760

EP - 2771

JO - Ecology

JF - Ecology

SN - 0012-9658

IS - 10

ER -