@article{fdi:010072055,
  title = {{H}ydro-ecological controls on dissolved carbon dynamics in groundwater and export to streams in a temperate pine forest},
  author = {{D}eirmendjian, {L}. and {L}oustau, {D}. and {A}ugusto, {L}. and {L}afont, {S}. and {C}hipeaux, {C}. and {P}oirier, {D}. and {A}bril, {G}wena{\¨e}l},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e studied the export of dissolved inorganic carbon ({DIC}) and dissolved organic carbon ({DOC}) from forested shallow groundwater to first-order streams, based on groundwater and surface water sampling and hydrological data. {T}he selected watershed was particularly convenient for such study, with a very low slope, with pine forest growing on sandy permeable podzol and with hydrology occurring exclusively through drainage of shallow groundwater (no surface runoff). {A} forest plot was instrumented for continuous eddy covariance measurements of precipitation, evapotranspiration, and net ecosystem exchanges of sensible and latent heat fluxes as well as {CO}2 fluxes. {S}hallow groundwater was sampled with three piezometers located in different plots, and surface waters were sampled in six first-order streams; river discharge and drainage were modeled based on four gauging stations. {O}n a monthly basis and on the plot scale, we found a good consistency between precipitation on the one hand and the sum of evapotranspiration, shallow groundwater storage and drainage on the other hand. {DOC} and {DIC} stocks in groundwater and exports to first-order streams varied drastically during the hydrological cycle, in relation with water table depth and amplitude. {I}n the groundwater, {DOC} concentrations were maximal in winter when the water table reached the superficial organic-rich layer of the soil. {I}n contrast, {DIC} (in majority excess {CO}2) in groundwater showed maximum concentrations at low water table during late summer, concomitant with heterotrophic conditions of the forest plot. {O}ur data also suggest that a large part of the {DOC} mobilized at high water table was mineralized to {DIC} during the following months within the groundwater itself. {I}n first-order streams, {DOC} and {DIC} followed an opposed seasonal trend similar to groundwater but with lower concentrations. {O}n an annual basis, leaching of carbon to streams occurred as {DIC} and {DOC} in similar proportion, but {DOC} export occurred in majority during short periods of the highest water table, whereas {DIC} export was more constant throughout the year. {L}eaching of forest carbon to first-order streams represented a small portion (approximately 2 %) of the net land {CO}2 sink at the plot. {I}n addition, approximately 75% of the {DIC} exported from groundwater was not found in streams, as it returned very fast to the atmosphere through {CO}2 degassing.},
  keywords = {{FRANCE}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {15},
  numero = {2},
  pages = {669--691},
  ISSN = {1726-4170},
  year = {2018},
  DOI = {10.5194/bg-15-669-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072055},
}