@article{fdi:010057293,
  title = {{P}articulate organic matter distribution along the lower {A}mazon {R}iver : addressing aquatic ecology concepts using fatty acids},
  author = {{M}ortillaro, {J}. {M}. and {R}igal, {F}. and {R}ybarczyk, {H}. and {B}ernardes, {M}. and {A}bril, {G}wena{\¨e}l and {M}eziane, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{O}ne of the greatest challenges in understanding the {A}mazon basin functioning is to ascertain the role played by floodplains in the organic matter ({OM}) cycle, crucial for a large spectrum of ecological mechanisms. {F}atty acids ({FA}s) were combined with environmental descriptors and analyzed through multivariate and spatial tools (asymmetric eigenvector maps, {AEM} and principal coordinates of neighbor matrices, {PCNM}). {T}his challenge allowed investigating the distribution of suspended particulate organic matter ({SPOM}), in order to trace its seasonal origin and quality, along a 800 km section of the {A}mazon river-floodplain system. {S}tatistical analysis confirmed that large amounts of saturated {FA}s (15: 0, 18: 0, 24: 0, 25: 0 and 26: 0), an indication of refractory {OM}, were concomitantly recorded with high p{CO}(2) in rivers, during the high water season ({HW}). {C}ontrastingly, {FA}s marker which may be attributed in this ecosystem to aquatic plants (18:2 omega 6 and 18:3 omega 3) and cyanobacteria (16:1 omega 7), were correlated with higher {O}-2, chlorophyll a and pheopigments in floodplains, due to a high primary production during low waters ({LW}). {D}ecreasing concentrations of unsaturated {FA}s, that characterize labile {OM}, were recorded during {HW}, from upstream to downstream. {F}urthermore, using {PCNM} and {AEM} spatial methods, {FA}s compositions of {SPOM} displayed an upstream-downstream gradient during {HW}, which was attributed to {OM} retention and the extent of flooded forest in floodplains. {D}iscrimination of {OM} quality between the {A}mazon {R}iver and floodplains corroborate higher autotrophic production in the latter and transfer of {OM} to rivers at {LW} season. {T}ogether, these gradients demonstrate the validity of {FA}s as predictors of spatial and temporal changes in {OM} quality. {T}hese spatial and temporal trends are explained by 1) downstream change in landscape morphology as predicted by the {R}iver {C}ontinuum {C}oncept; 2) enhanced primary production during {LW} when the water level decreased and its residence time increased as predicted by the {F}lood {P}ulse {C}oncept.},
  keywords = {},
  booktitle = {},
  journal = {{P}los {O}ne},
  volume = {7},
  numero = {9},
  pages = {e46141},
  ISSN = {1932-6203},
  year = {2012},
  DOI = {10.1371/journal.pone.0046141},
  URL = {https://www.documentation.ird.fr/hor/fdi:010057293},
}