@article{fdi:010014984,
  title = {{P}hytoliths : indicators of grassland dynamics during the late {H}olocene in intertropical {A}frica},
  author = {{A}lexandre, {A}. and {M}eunier, {J}.{D}. and {L}{\'e}zine, {A}.{M}. and {V}incens, {A}. and {S}chwartz, {D}ominique},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he reconstruction of {A}frican tropical grassland history during the late {H}olocene can be carried out using phytolith analysis. {F}ossil phytolith assemblages from {L}ake {G}uiers, in the {S}ahelian region of {S}enegal, and from {L}ake {S}innda, in the {G}uineo-{C}ongolian region of {C}ongo were investigated. {T}he results are interpreted on the basis of modern phytolith assemblages from the same regions and compared to pollen data previously obtained. {T}all or short grass associations are discriminated by their phytolith index {I}ph(%) = saddle/(cross+dumbel+saddle), while the density of shrubs and trees is indicated by relative proportions of the dicotyledon phytoliths. {T}he phytolith data emphasize that, in the {G}uineo-{C}ongolian region around {L}ake {S}innda, the driest phase of the late {H}olocene occurred between 4000 and 1200 yr {B}.{P}., commencing with the opening of the dense forest and its replacement by a short grass savanna. {F}rom ca. 1000 yr {B}.{P}., wetter climatic conditions developed, as represented by the setting up of a tall grass savanna woodland. {T}he modern shrub and tall grass savanna was developed ca. 700 yr {B}.{P}. {I}n the {S}ahelian region around {L}ake {G}uiers, the driest phase occurred after about 2000 yr {B}.{P}. and has not been followed by moister conditions. {A} tall grass savanna woodland was gradually replaced by a shrub and short grass savanna which still occurs. {A} short period of development of swampy vegetation, which can be related to a lake level change, interrupted the semi-arid adaptation of the vegetation, between about 2000 yr {B}.{P}. and the present. ({R}{\'e}sum{\'e} d'auteur)},
  keywords = {{QUATERNAIRE} ; {HOLOCENE} ; {PALEOENVIRONNEMENT} ; {MILIEU} {LACUSTRE} ; {PALEOBOTANIQUE} ; {PALYNOLOGIE} ; {PHYTOLITHE} ; {SENEGAL} ; {ZONE} {SAHELIENNE} ; {CONGO} ; {GUIERS} {LAC} ; {SINNDA} {LAC}},
  booktitle = {},
  journal = {{P}alaeogeography, {P}alaeoclimatology, {P}alaeoecology},
  volume = {136},
  numero = {1-4},
  pages = {213--229},
  ISSN = {0031-0182},
  year = {1997},
  DOI = {10.1016/{S}0031-0182(97)00089-8},
  URL = {https://www.documentation.ird.fr/hor/fdi:010014984},
}