Climate ultrastructure and aquatic community response to Heinrich Stadials (HS5a-HS1) in the continental northern Neotropics

Influence of late Quaternary climate on the biogeography of Neotropical aquatic species as reflected by non-marine ostracodes

“…All samples had a volume of 3 cm 3 of wet sediments. Ostracode separation methods and counting can be found in Cohuo et al (2018). We looked at near-continuous ostracode fossil occurrences in the sediments over the last 155 kyr.…”

“…In the northern Neotropics, which include southern Mexico, Central America and the Antilles, late Quaternary climate inferences based on climatic simulations with global climate models (GCMs; Hijmans et al, 2005) and reconstructions from marine and lacustrine sedimentary sequences (Hodell et al, 2008;Pérez et al, 2011;Escobar et al, 2012) have revealed climate fluctuations related to temperature and precipitation, especially during transitions between glacial and interglacial episodes and during climate pulses such as the last glacial maximum (LGM) and Heinrich stadials (HSs; Correa-Metrio et al, 2012b). In the Neotropics, controls of climate fluctuations are related to orbital forcing and internal component variations, such as the position (northsouth) of the intertropical convergence zone (ITCZ), strength of Atlantic meridional overturning circulation (AMOC) and changes in Caribbean surface water temperature (Cohuo et al, 2018). Alterations in these features have produced temperature decreases in a range of 3-5 • C, although some estimations suggest decreases up to 10 • C relative to present and large reductions in precipitation, particularly during HS, when most lakes in the region dried completely (Cohuo et al, 2018).…”

“…In the Neotropics, controls of climate fluctuations are related to orbital forcing and internal component variations, such as the position (northsouth) of the intertropical convergence zone (ITCZ), strength of Atlantic meridional overturning circulation (AMOC) and changes in Caribbean surface water temperature (Cohuo et al, 2018). Alterations in these features have produced temperature decreases in a range of 3-5 • C, although some estimations suggest decreases up to 10 • C relative to present and large reductions in precipitation, particularly during HS, when most lakes in the region dried completely (Cohuo et al, 2018). Correa-Metrio et al (2014) found evidence for rapid climate change in terrestrial environments during HSs, which was associated with major ecological and biological shifts (Loarie et al, 2009;Burrows et al, 2011;Sandel et al, 2011).…”

“…In this study, we addressed three overarching questions. (1) Have past climate changes since 155 ka (Hodell et al, 2008;Correa-Metrio et al, 2012aCohuo et al, 2018) had profound consequences for aquatic ecosystem stability in the northern Neotropics? (2) Did endemic and nonendemic (widespread) species respond in the same way to climate shifts?…”

Achnanthidium neotropicum sp. nov., a new freshwater diatom from Lake Apastepeque in El Salvador (Central America)

“…Chávez & Haberyan 1996, Haberyan & Horn 1999, 2005, Guatemala (e.g. Rosenmeier et al 2004, Cohuo et al 2018, Nicaragua (e.g. Slate et al 2013) andPanama (e.g.…”