@article{fdi:010063517,
  title = {{V}egetation impact on stream chemical fluxes : {M}ule {H}ole watershed ({S}outh {I}ndia)},
  author = {{R}iotte, {J}ean and {M}ar{\'e}chal, {J}.{C}. and {A}udry, {S}. and {K}umar, {C}. and {B}edimo, {J}. {P}. {B}. and {R}uiz, {L}aurent and {S}ekhar, {M}. and {C}isel, {M}. and {T}arak, {R}. {C}. and {V}arma, {M}. {R}. {R}. and {L}agane, {C}hristelle and {R}eddy, {P}. and {B}raun, {J}ean-{J}acques},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he proportion of chemical elements passing through vegetation prior to being exported in a stream was quantified for a forested tropical watershed ({M}ule {H}ole, {S}outh {I}ndia) using an extensive hydrological and geochemical monitoring at several scales. {F}irst, a solute annual mass balance was established at the scale of the soil-plant profile for assessing the contribution of canopy interaction and litter decay to the solute fluxes of soil inputs (overland flow) and soil outputs (pore water flow as seepages). {S}econd, based on the respective contributions of overland flow and seepages to the stream flow as estimated by a hydrological lumped model, we assigned the proportion of chemical elements in the stream that transited through the vegetation at both flood event ({E}nd {M}ember {M}ixing {A}nalysis) and seasonal scales. {A}t the scale of the 1{D} soil-plant profile, leaching from the canopy constituted the main source of {K} above the ground surface. {L}itter decay was the main source of {S}i, whereas alkalinity, {C}a and {M}g originated in the same proportions from both sources. {T}he contribution of vegetation was negligible for {N}a. {W}ithin the soil, all elements but {N}a were removed from the pore water in proportions varying from 20% for {C}l to 95% for {K}: {T}he soil output fluxes corresponded to a residual fraction of the infiltration fluxes. {T}he behavior of {K}, {C}l, {C}a and {M}g in the soil-plant profile can be explained by internal cycling, as their soil output fluxes were similar to the atmospheric inputs. {N}a was released from soils as a result of {N}a-plagioclase weathering and accompanied by additional release of {S}i. {C}oncentration of soil pore water by evapotranspiration might limit the chemical weathering in the soil. {O}verall, the solute {K}, {C}a, {M}g, alkalinity and {S}i fluxes associated with the vegetation turnover within the small experimental watershed represented 10-15 times the solute fluxes exported by the stream, of which 83-97% transited through the vegetation. {O}ne important finding is that alkalinity and {S}i fluxes at the outlet were not linked to the "current weathering" of silicates in this watershed. {T}hese results highlight the dual effect of the vegetation cover on the solute fluxes exported from the watershed: {O}n one hand the runoff was limited by evapotranspiration and represented only 10% of the annual rainfall, while on the other hand, 80-90% of the overall solute flux exported by the stream transited through the vegetation. {T}he approach combining geochemical monitoring and accurate knowledge of the watershed hydrological budget provided detailed understanding of several effects of vegetation on stream fluxes: (1) evapotranspiration (limiting), (2) vertical transfer through vegetation from vadose zone to ground surface (enhancing) and (3) redistribution by throughfalls and litter decay. {I}t provides a good basis for calibrating geochemical models and more precisely assessing the role of vegetation on soil processes.},
  keywords = {{INDE} {SUD}},
  booktitle = {},
  journal = {{G}eochimica et {C}osmochimica {A}cta},
  volume = {145},
  numero = {},
  pages = {116--138},
  ISSN = {0016-7037},
  year = {2014},
  DOI = {10.1016/j.gca.2014.09.015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010063517},
}