H. Elenga

Paleoclimatic changes are the most probable causes of the rainforest crises 2,600 y ago in Central Africa

In PNAS, Garcin et al. (1) describe a Late Holocene rainforest crisis (LHRC) between ∼2,600 and 2,000 calendar years B.P. in Lake Barombi (Southwest Cameroon) when tropical rainforest was replaced by savannah, as attested by a large peak in Poaceae pollen (30–40%), and correlated with a shift in the δ13C organic carbon from −34 to −29 ‰ Pee Dee Belemnite (2). The authors use the isotopic composition of plant leaf waxes preserved in the sediments as an estimated independent paleoclimate recorder of precipitation (3). Indeed, climate and environment can broadly affect the deuterium/hydrogen (D/H) ratios of plant materials, but the degree to which different plant species’ leaf wax D/H ratios are … [↵][1]1To whom correspondence should be addressed. Email: charles.doumenge{at}cirad.fr. [1]: #xref-corresp-1-1