Lowland rainforest response to hydrological changes during the last 1500 years in Gabon, Western Equatorial Africa

摘要: Pollen and δ 13 CTOM data obtained from two contrasting lake sequences (Lakes Kamalete Nguene), located 200 km apart in the lowland rainforest of Gabon, provide complementary local regional 1500-yr records high resolution (15–30 yr) vegetation change. A combination aquatic, semi-aquatic terrestrial pollen showed both that tropical increased during periods rainfall decreased drought intervals. The strong fluctuations water balance at decadal scale “Medieval Warm Period” (∼1100–800 cal yr BP) coincided with a noticeable increase shade-intolerant taxa, indicating recurring canopy disturbance. signal highamplitudevariationsinbothrecords,whichpositivelycorrelateswiththerainforestdynamicsandlocalvegetationchanges.Thesimilartrendsinboth andthe CTOMsignals between these sites demonstrate broadly synchronoustiming ofshifting hydrological conditions.The largely positive co-variation conditions changes structure composition indicate climatic change is probably driving force for major dynamics Gabon. Any significant anthropogenic impact on has not been clearly identified, this issue still needs to be resolved independently by obtaining detailed archeological across interval 1400–800 BP, which currently seem extremely rare or easily available. © 2007 University Washington. All rights reserved.