Environmental change in northern Belize since the latest Pleistocene

Abstract

Cores from the New River Lagoon in Belize have been analysed using a range of palaeolimnological proxies to reconstruct change since the latest Pleistocene. The combination of diatom and stable isotope analyses (supported by mineralogical and major element data) indicate that the New River Lagoon has been a freshwater system throughout the period of record. For most of this time the lagoon has been hydrologically open, but there are indications that it may have become closed in the latest Pleistocene or very early Holocene. This may have been associated with a drier climate and lower sea level. Mid-Holocene records are consistent with those from elsewhere in the region, indicating a stable and moist climate. The late Holocene was marked by greater variability, but there is no clear evidence of any drying in the late Classic coincident with the Maya 'collapse' ca. AD 900. Our results indicate that the continuity of occupation at the Maya site of Lamanai on the shores of the New River Lagoon is consistent with continued access to freshwater during periods of regional climatic variability. The importance of conditions at individual sites when considering both system response and human vulnerability to climate change is emphasised.

The role of glacial cycles in promoting genetic diversity in the Neotropics: the case of cloud forests during the Last Glacial Maximum

“…This reduction has also been observed in New River Lagoon, Belize (Metcalfe et al. ) and Lake Quexil, Guatemala (Leyden et al. ).…”

“…Moreover, the studies of Leyden et al (1993), Bradbury (1997, Anselmetti et al (2006), and Metcalfe et al (2009) suggested a reduction in wet season precipitation for upper Central America and Mexico. Bradbury (1997) observed dominant grasslands in records around the Caribbean basin, indicative of cooler and dryer climate.…”

The Holocene history of the North American Monsoon: ‘known knowns’ and ‘known unknowns’ in understanding its spatial and temporal complexity

“…85,000 years) and has been analysed using a range of methods (Hillesheim et al, 2005;Hodell et al, 2008;Mueller et al, 2009;Bush et al, 2009;Correa-Metrio et al, 2012;Escobar et al, 2012). Following the early pollen work of Barbara Leyden (Leyden, 1984;Leyden et al, 1993Leyden et al, , 1994 Am) offers clear potential for dating the most recent parts of sediment sequences, but to date their application has been limited and has met with variable success (Metcalfe et al, 2009). In this limestone region, speleothems clearly have great potential to yield high-resolution records (using U-series dating), but so far most records cover only the late Holocene and there have been problems in obtaining reliable chronologies for some sites (D. Hodell and M. Brenner, pers.…”

The bigger picture: towards integrating palaeoclimate and environmental data with a history of societal change

“…Understanding the causes of the Mayan collapse highlights the real problem of having excellent archaeological and palaeolimnological datasets that may not represent the complete region (e.g. Metcalfe et al, 2009) and/or have limited chronological control: 'Chronological control . .…”