@article{fdi:010061784,
  title = {{C}arbon sinks in small {S}ahelian lakes as an unexpected effect of land use changes since the 1960s ({S}aga {G}orou and {D}allol {B}osso, {SW} {N}iger)},
  author = {{O}bame, {R}. {M}. and {C}opard, {Y}. and {S}ebag, {D}avid and {T}oure, {A}. {A}. and {B}oussafir, {M}. and {B}ichet, {V}. and {G}arba, {Z}. and {G}uillon, {R}. and {P}etit, {C}. and {R}ajot, {J}ean-{L}ouis and {D}urand, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{F}or several decades, global change has resulted in an increase in runoff in the {S}ahelian belt, provoking major changes in the quality and quantity of sediments transported by drainage networks. {O}ne of the astonishing consequences is the establishment of numerous permanent lakes. {T}he origins of particulate organic matter ({OM}) preserved within lacustrine sediments of three lakes were investigated by coupling optical observations (palynofacies) and bulk geochemistry ({R}ock-{E}val 6 pyrolysis). {A}n initial estimate of particulate organic carbon ({OC}) stored in these lacustrine sediments was assessed. {S}oil organic matter ({SUM}) was sampled from the surface (0-10 cm) of various land-use and land-cover areas and was characterized and compared with sedimentary organic matter. {O}ur results reveal that {L}ake {T}ankalawal is subjected to high autochthonous organic sedimentation ({TOC} ranges between 3.0 and 10.0 wt.%), while lakes {B}angou {K}irey and {B}i are characterized by weak sedimentation of non-indigenous {OM} originating from the soil erosion and shore vegetation ({TOC} <3.0 wt.%). {I}n sediments, the effects of early diagenesis on the {OM} induce not only a loss of labile and aquatic {OM} but also a significant loss of terrestrial {OM}, which is supposed to be more resistant than its aquatic counterpart. {B}oth the preservation of {OM} in top sediments and the relative preservation of terrestrial {OM} impact the {CC} storage in lakes. {I}ndeed, {CC} storage in lacustrine sediments ({L}ake {B}angou {K}irey) was two to seven times higher than the {CC} storage in {S}ahelian soils, where greater contributions of terrestrial {OM} to sedimentary {OM} are associated with lower {OC} storage in lacustrine sediments. {F}or lakes {B}angou {K}irey and {B}i, {CC} accumulation rates were also assessed; due to the identification of a sedimentary limit corresponding to the establishment of permanent lakes dated earlier 1960s. {H}igh {CC} fluxes were estimated and ranged between 104 and 213 g {CC} m(-2) yr(-1). {C}ompared with other {CC} accumulation rates for various {A}frican lakes, these high values are similar to those calculated for reservoirs and are related to anthropogenic pressure, soil textures favoring erosion, and proper physical and chemical conditions for {OM} preservation in sediments. {A}ccordingly, in these {S}ahelian environments that are generally viewed as non-efficient in storing {CC}, we claim that global change could promote a new {CC} sink. {I}f other similar studies reinforce our assertion, then regional {C} budgets should be revisited.},
  keywords = {{P}articulate organic matter ; {C}arbon sink ; {S}oil erosion ; {L}akes ; {S}ahel ; {G}lobal change ; {NIGER} ; {ZONE} {SAHELIENNE}},
  booktitle = {},
  journal = {{C}atena},
  volume = {114},
  numero = {},
  pages = {1--10},
  ISSN = {0341-8162},
  year = {2014},
  DOI = {10.1016/j.catena.2013.10.008},
  URL = {https://www.documentation.ird.fr/hor/fdi:010061784},
}