학술논문

Sporormiella and the late Holocene extinctions in Madagascar
Document Type
Author Abstract
Source
Proceedings of the National Academy of Sciences of the United States. Sept 16, 2003, Vol. 100 Issue 19, p10800, 6 p.
Subject
Spores (Botany) -- Research
Science and technology
Language
English
ISSN
0027-8424
Abstract
Fossil spores of the dung fungus Sporormiella spp. in sediment cores from throughout Madagascar provide new information concerning megafaunal extinction and the introduction of livestock. Sporormiella percentages are very high in prehuman southwest Madagascar, but at the site with best stratigraphic resolution the spore declines sharply by [approximately equal to] 1,720 yr B.P. (radiocarbon years ago). Within a few centuries there is a concomitant rise in microscopic charcoal that probably represents human transformation of the local environment. Reduced megaherbivore biomass in wooded savannas may have resulted in increased plant biomass and more severe fires. Some now-extinct taxa persisted locally for a millennium or more after the inferred megafaunal decline. Sites in closed humid forests of northwest Madagascar and a montane ericoid formation of the central highlands show only low to moderate Sporormiella percentages before humans. A subsequent rise in spore concentrations, thought to be evidence for livestock proliferation, occurs earliest at Amparihibe in the northwest at [approximately equal to] 1,130 yr B.P.