A 10,300 14C yr Record of Climate and Vegetation Change from Haiti
Pleistocene and Holocene vegetation dynamics in the American tropics are inferred largely from pollen in continental lake sediments. Maritime influences may have moderated climate and vegetation changes on Caribbean islands. Stable isotope (delta(18)O) study of a 7.6-m core from Lake Miragoane, Haiti, provided a high-resolution record of changing evaporation/precipitation (E/P) since similar to 10,300 C-14 yr B.P. The Miragoane pollen record documents climate influences and human impacts on vegetation in Hispaniola. The delta(18)O and pollen data near the base of the core indicate cool, dry conditions before similar to 10,000 C-14 yr B.P. Lake Miragoane filled with water in the early Holocene as E/P declined and the freshwater aquifer rose. Despite increasing early Holocene moisture, shrubby, xeric vegetation persisted. Forest expanded similar to 7000 C-14 yr B.P. in response to greater effective moisture and warming. The middle Holocene (similar to 7000-3200 C-14 yr B.P,) was characterized by high lake levels and greatest relative abundance of pollen from moist forest taxa, Climatic drying that began similar to 3200 C-14 yr B.P. may have driven some mesophilic animal species to extinction. The pollen record of the last millennium reflects pre-Columbian (Taino) and European deforestation, Long-term, Holocene vegetation trends in southern Haiti are comparable to trends from continental, lowland circum-Caribbean sites, suggesting a common response to regional climate change. (C) 1999 University of Washington.