Late Holocene environmental reconstruction using cave sediments from Belize

Cave sediments collected from Reflection Cave on the Vaca Plateau, Belize show variations in the delta C-13 values of their fulvic acids (FAs), which indicate periods of vegetation change caused by climatic and Maya influences during the late Holocene. The delta C-13 values range from -27.11%. to -21.52%o, a shift of similar to 5.59%, which suggests fluctuating contributions of C-3 and C-4 plants throughout the last 2.5 ka, with C-4 plant input reflecting periods of Maya agriculture. Maya activity in the study area occurred at different intensities from similar to 2600 cal yr BP until similar to 1500 cal yr BP, after which agricultural practices waned as the Maya depopulated the area. These changes in plant assemblages were in response to changes in available water resources, with increased aridity leading to the eventual abandonment of agricultural areas. The Ix Chel archaeological site, located in the study area, is a highland site that would have been among the first agricultural settlements to be affected during periods of aridity. During these periods, minimal water resources would have been available in this highly karstified, well-drained area, and supplemental groundwater extraction would have been difficult due to the extreme depth of the water table. (c) 2007 University of Washington. All rights reserved.