@article{PAR00009796,
  title = {{T}owards an understanding of {W}est {A}frican montane forest response to climate change},
  author = {{L}ezine, {A}nne-{M}arie and {A}ssi-{K}audjhis, {C}. and {R}oche, {E}. and {V}incens, {A}. and {A}choundong, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}im {O}ur aims were to provide a detailed chronology of past vegetation changes in the tropical mountains of west-central {A}frica since the {L}ast {G}lacial {M}aximum and to discuss montane forest responses to climate change in terms of distribution and biodiversity. {L}ocation {L}ake {B}ambili, western {C}ameroon (05 degrees 56' {N}, 10 degrees 14' {E}, 2273 m a.s.l.). {M}ethods {F}ossil pollen was extracted from a long, continuous and well-dated sedimentary sequence extending back 20,000 years. {P}ollen diversity and evenness estimates were based on rarefaction analysis and on {S}impson's (1/{D}) index. {R}esults {F}orest was nearly absent from high elevations during the last glacial period. {I}t expanded gradually from 18.4 cal. kyr bp, interrupted only by reversals coincident with the {H}einrich 1 ({H}1) and {Y}ounger {D}ryas ({YD}) climatic events, and then suddenly collapsed at 3.3 cal. kyr bp. {T}his switch from forest to grassland communities occurred within a time span of three centuries. {A}fter 3.3 cal. kyr bp only short and taxon-poor forest phases are recorded, specifically between 2.7 and 1 cal. kyr bp and in recent centuries. {M}ain conclusions {O}ur data indicate that the mountain forests of {C}ameroon are recent, resulting from plant migrations from various sources from 18.4 cal. kyr bp onwards. {T}heir progressive development closely followed intensification of the {A}tlantic monsoon, leading to the formation of a dense forest between 11.7 and 3.3 cal. kyr bp. {T}he composition of this forest included the co-occurrence of species whose ranges do not overlap today, and indicates the potential for the development of unique iterations of climax forests through time. {T}hese forests appear to be very sensitive to {N}orthern {H}emisphere climate change, with phases of expansion/contraction coeval with the boreal deglacial signal, including widely recognized events such as {H}1, the {YD} and the 8.2 ka event. {F}rom 8.2 cal. kyr bp onwards, the progressive opening of the canopy is likely to reflect increased seasonality in rainfall related to more frequent {E}l {N}ino/{S}outhern {O}scillation ({ENSO}) events. {T}he final step of this history was the collapse of the montane forest at 3.3 cal. kyr bp. {D}uring the last millennium, very severe disruptions have meant that only the most rapidly dispersing species could spread, contributing to a drastic loss of forest biodiversity that has been accentuated by human impact in the last few centuries.},
  keywords = {{A}frica ; biodiversity ; {C}ameroon ; late {Q}uaternary ; montane forest ; palaeoclimate ; palynology ; vegetation dynamics ; {AFRIQUE} {DE} {L}'{OUEST}},
  booktitle = {},
  journal = {{J}ournal of {B}iogeography},
  volume = {40},
  numero = {1},
  pages = {183--196},
  ISSN = {0305-0270},
  year = {2013},
  DOI = {10.1111/j.1365-2699.2012.02770.x},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00009796},
}