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

Abstract

Abstract. We evaluated how ranges of four endemic and non-endemic aquatic ostracode species changed in response to long-term (glacial–interglacial cycles) and abrupt climate fluctuations during the last 155 kyr in the northern Neotropical region. We employed two complementary approaches, fossil records and species distribution models (SDMs). Fossil assemblages were obtained from sediment cores PI-1, PI-2, PI-6 and Petén-Itzá 22-VIII-99 from the Petén Itzá Scientific Drilling Project, Lake Petén Itzá, Guatemala. To obtain a spatially resolved pattern of (past) species distribution, a downscaling cascade is employed. SDMs were reconstructed for the last interglacial (∼120 ka), the last glacial maximum (∼22 ka) and the middle Holocene (∼6 ka). During glacial and interglacial cycles and marine isotope stages (MISs), modelled paleo-distributions and paleo-records show the nearly continuous presence of endemic and non-endemic species in the region, suggesting negligible effects of long-term climate variations on aquatic niche stability. During periods of abrupt ecological disruption such as Heinrich Stadial 1 (HS1), endemic species were resilient, remaining within their current areas of distribution. Non-endemic species, however, proved to be more sensitive. Modelled paleo-distributions suggest that the geographic range of non-endemic species changed, moving southward into Central America. Due to the uncertainties involved in the downscaling from the global numerical to the highly resolved regional geospatial statistical modelling, results can be seen as a benchmark for future studies using similar approaches. Given relatively moderate temperature decreases in Lake Petén Itzá waters (∼5 ∘C) and the persistence of some aquatic ecosystems even during periods of severe drying in HS1, our data suggest (1) the existence of micro-refugia and/or (2) continuous interaction between central metapopulations and surrounding populations, enabling aquatic taxa to survive climate fluctuations in the northern Neotropical region.

Subterranean Waters of Yucatán Peninsula, Mexico Reveal Epigean Species Dominance and Intraspecific Variability in Freshwater Ostracodes (Crustacea: Ostracoda)

“…In terms of freshwater availability, Lake Petén Itzá decreased during the Heinrich stadial 1 by about 50 m with respect to their current water level, with a reduction of about 80% of the total area [100][101][102][103]. This estimation allows us to postulate that water systems in the entire Yucatán Peninsula were severely affected by similar magnitudes as Lake Petén Itzá [98,99,101].…”

Millennial hydrological variability in the continental northern Neotropics during MIS3-2 inferred from sediments of Lake Petén Itzá, Guatemala

“…provided by the PI-2 record that indicate substantial precipitation in the study area during the deposition of Unit 6 (Cohuo et al, 2020).…”

“…Ages and their uncertainties are indicated in blue. Red-solid line shows the chronology obtained byKutterolf et al, (2016) and used inCohuo et al, (2018Cohuo et al, ( , 2020. Red-dotted line represents the average age, while black-dotted line is the minimum and maximum range of each age.…”

Evaluation of Lake Sediment Thickness from Water-Borne Electrical Resistivity Tomography Data

“…These changes can be reconstructed from fossil microcrustaceans, diatoms, microbes, pollen, and other biological and non-biological components. Deposited and stored on the lake bed building layers of sediment [ 2 , 3 ], these indicators provide high-resolution information on past environmental changes [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. There is special interest in recovering unaltered and old sediments from ancient lakes to provide a continuous and long historical record of climate and environmental change [ 11 , 12 , 13 , 14 , 15 ].…”