Paleoecology of Twin Cays: interpretation of palynological, isotopic, and stomatal proxies in a peat core from Belize

Abstract

Reconstructions of Holocene climate from numerous mid- and high-latitude sites have identified millennial-scale cool and arid intervals at 8,200 and 4,200 yrs. B.P. The global nature of these events can only be established by examination of Holocene climate records from low latitude sites. The Central American island of West Twin Cays was chosen as the study location due to its thick peat deposits, which allow for the reconstruction of Holocene vegetation, sea level, and climate for the Belize coastal region. Rhizophora mangle (red mangrove) dominated the island's vegetation since its formation 8,200 cal. yrs. B.P. Alternating periods dominated by dwarf or tall R. mangle reflect changes in phosphorus and nitrogen availability. Heightened Myrsine-type pollen concentrations between 6,300 and 4,200 cal. yrs. B.P. suggests lower sea levels and drier climates. Regional warming accompanied by increased precipitation in the middle to late Holocene is recorded by an increase in exotic Pinus concentrations. These vegetation shifts correlate with regional Central American climate changes and westem Atlantic sea level shifts at 8,200 and 4,200 cal. yrs. B.P. More importantly, these data link Central American changes to worldwide climate events.