@article{fdi:010067718,
  title = {{T}he fate of {C}-4 and {C}-3 macrophyte carbon in central {A}mazon floodplain waters : insights from a batch experiment},
  author = {{M}ortillaro, {J}. {M}. and {P}assarelli, {C}. and {A}bril, {G}wena{\¨e}l and {H}ubas, {C}. and {A}lberic, {P}. and {A}rtigas, {L}. {F}. and {B}enedetti, {M}. {F}. and {T}hiney, {N}. and {M}oreira {T}urcq, {P}atricia and {P}erez, {M}. {A}. {P}. and {V}idal, {L}. {O}. and {M}eziane, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he central {A}mazon floodplains are particularly productive ecosystems, where a large diversity of organic carbon sources are available for aquatic organisms. {D}espite the fact that {C}-4 macrophytes generally produce larger biomasses than {C}-3 macrophytes, food webs in the central {A}mazon floodplains appear dominantly based on a {C}-3 carbon source. {I}n order to investigate the respective fate and degradation patterns of {C}-4 and {C}-3 aquatic plant-derived material in central {A}mazon floodplains, we developed a 23-days batch experiment. {F}atty acid and carbon concentrations as well as stable isotope compositions were monitored over time in 60 {L} tanks. {T}hese tanks contained {A}mazon water, with different biomasses of {C}-3 and {C}-4 macrophyte, representative of in situ densities occurring in central {A}mazon floodplains. {I}n the {C}-4 {P}aspalum repens treatments, organic ({POC}, {DOC}) and inorganic carbon ({DIC}) got rapidly enriched in {C}-13, whereas in the {C}-3 {S}alvinia auriculata treatments, {POC} and {DOC} showed little change in concentration and isotopic composition, and {DIC} got depleted in {C}-13. {T}he contribution of {P}. repens to {POC} and {DOC} was estimated to reach up to 94.2 and 70.7%, respectively. {I}n contrast, no differences were reported between the {C}-3 {S}. auriculata and control treatments, an observation attributed to the lower {C}-3 biomass encountered in the field, to a slower degradation rate of {C}-3 compared to {C}-4 compounds, and to similar isotopic compositions for river {POC} and {DOC}, and {C}-3 compounds. {T}he {C}-13 enrichments of {POC}, {DOC}, and {DIC} from {P}. repens treatments were attributed to an enhanced bacterially-mediated hydrolysis and mineralization of {C}-4 material. {E}volutions of bacterial abundance and branched fatty acid concentrations confirmed the role of heterotrophic microbial communities in the high {P}. repens decomposition rate. {O}ur experiment highlights the predominant role of {C}-4 aquatic plants, as a large source of almost entirely biodegradable organic matter available for heterotrophic activity and {CO}2 outgassing to the atmosphere.},
  keywords = {{C}entral amazon ; {F}loodplains ; {F}atty acids ; {S}tables isotopes ; {M}acrophytes ; {D}egradation ; {BRESIL} ; {AMAZONE} {BASSIN} ; {CAMALEAO} {LAC}},
  booktitle = {},
  journal = {{L}imnologica},
  volume = {59},
  numero = {},
  pages = {90--98},
  ISSN = {0075-9511},
  year = {2016},
  DOI = {10.1016/j.limno.2016.03.008},
  URL = {https://www.documentation.ird.fr/hor/fdi:010067718},
}