6533b7d7fe1ef96bd1268b74

RESEARCH PRODUCT

Cycles diurnes de rayonnement solaire et forets en Afrique Centrale.

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The sunlightconditions prevailing in Central Africa, and their potential impact on forests traits and functioning, have neverbeen fully explored. Using satellite estimates documenting mostly the period 2005-2013, and accounting forscale interactions between the diurnal and annual cycles, we demonstrate that the seasonality of sunlight levelsstrongly vary across Central Africa forests. Gabon stands out with a main dry season strongly light-deficient,cool and moist. An original map of terra firme forest types developed by CIRAD shows that most of theevergreen forests of Central Africa develop in Gabon. We postulate that despite a mean annual precipitationamount below 2000 mm/yr, the Gabonese climate can harbor most of the evergreen forests of Central Africabecause of a heavy cloudiness which reduces the water demand and decreases the direct to diffuse light ratio.These findings and the methodology developed pave the way for further analyses of the past and future changesin the light-deficient climates of Western Central Africa and the vulnerability of the evergreen forests to thesechanges.