@article{fdi:010072359,
  title = {{B}iogeochemical diversity, {O}-2-supersaturation and hot moments of {GHG} emissions from shallow alkaline lakes in the {P}antanal of {N}hecolandia, {B}razil},
  author = {{B}arbi{\'e}ro, {L}aurent and {N}eto, {M}. {S}. and {B}raz, {R}. {R}. and do {C}armo, {J}. {B}. and {R}ezende, {A}. {T}. and {M}azzi, {E}. and {F}ernandes, {F}. {A}. and {D}amatto, {S}. {R}. and de {C}amargo, {P}. {B}.},
  editor = {},
  language = {{ENG}},
  abstract = {{N}hecolandia is a vast sub-region of the {P}antanal wetland in {B}razilwith great diversity in surface water chemistry evolving in a sodic alkaline pathway under the influence of evaporation. {I}n this region, >15,000 shallowlakes are likely to contribute an enormous quantity of greenhouse gas to the atmosphere, but the diversity of the biogeochemical scenarios and their variability in time and space is a major challenge to estimate the regional contribution. {F}rom 4 selected alkaline lakes, we compiled measurements of the physico-chemical characteristics ofwater and sediments, gas fluxes in floating chambers, and sedimentation rates to illustrate this diversity. {A}lthough these lakes have a similar chemical composition, the results confirm a difference between the black-water and green-water alkaline lakes, corresponding to distinct biogeochemical functioning. {T}his difference does not appear to affect lake sedimentation rates, but is reflected in gas emissions. {B}lack-water lakes are {CO}2 and {CH}4 sources, with fairly constant emissions throughout the seasons. {A}nnual carbon dioxide and methane emissions approach 0.86 mol m(-2) y(-1) and 0.07 mol m(-2) y(-1), respectively, and no clear trend towards {N}2{O} capture or emissionwas observed. {B}y contrast, green-water lakes are {CO}2 and {N}2{O} sinks but important {CH}4 sources with fluxes varying significantly throughout the seasons, depending on the magnitude of the phytoplankton bloom. {T}he results highlight important daily and seasonal variations in gas fluxes, and in particular a hot moments for methane emissions, when the {O}-2(-) supersaturation is reached during the afternoon under extreme bloom and sunny weather conditions, provoking an abrupt {O}-2 purging of the lakes. {T}aking into account the seasonal variability, annual methane emissions are around 10.2 mol m(-2) y(-1), i. e., much higher than reported in previous studies for alkaline lakes in {N}hecolandia. {C}arbon dioxide and nitrous oxide consumption is estimated about 1.9 mol m(-2) y(-1) and 0.73 mmol m(-2) y(-1), respectively. {H}owever, these balances must be better constrained with systematic and targeted measurements throughout the seasons.},
  keywords = {{G}reenhouse gas emission ; {O}-2 supersaturation ; {A}lkaline lakes ; {P}antanal ; wetland ; {B}razil ; {BRESIL}},
  booktitle = {},
  journal = {{S}cience of the {T}otal {E}nvironment},
  volume = {619},
  numero = {},
  pages = {1420--1430},
  ISSN = {0048-9697},
  year = {2018},
  DOI = {10.1016/j.scitotenv.2017.11.197},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072359},
}