Ecological turnover in neotropical freshwater and terrestrial communities during episodes of abrupt climate change

Liseth Pérez,Steffen Kutterolf,Laura Macario González,Antje Schwalb,Mark Brenner,Sergio Cohuo,Alex Correa-Metrio,Paula Echeverría-Galindo,Jason Curtis,Mona Stockhecke,Thorsten Bauersachs,Frederik Schenk

doi:10.1017/qua.2020.124

Abstract

ABSTRACT The last 85,000 years were characterized by high climate and environmental variability on the Yucatán Peninsula. Heinrich stadials are examples of abrupt climate transitions that involved shifts in regional temperatures and moisture availability. Thus, they serve as natural experiments to evaluate the contrasting responses of aquatic and terrestrial ecosystems. We used ostracodes and pollen preserved in a 75.9-m-long sediment core (PI-6, ~85 ka) recovered from Lake Petén Itzá, Guatemala, to assess the magnitude and velocity of community responses. Ostracodes are sensitive to changes in water temperature and conductivity. Vegetation responds to shifts in temperature and the ratio of evaporation to precipitation. Ostracodes display larger and more rapid community changes than does vegetation. Heinrich Stadial 5-1 (HS5-1) was cold and dry and is associated with lower ostracode and vegetation species richness and diversity. In contrast, the slightly warmer and dry conditions during HS6 and HS5a are reflected in higher ostracode species richness and diversity. Our paleoecological study revealed the greatest ecological turnover for ostracodes occurred from 62.5 to 51.0 ka; for pollen, it was at the Pleistocene/Holocene transition. Future studies should use various climate and environmental indicators from lake and marine sediment records to further explore late glacial paleoclimate causes and effects in the northern neotropics.

Highlights

High-resolution continental paleoclimate/paleoenvironment data sets that extend into the Pleistocene are rare, especially from the northern neotropics, a region where shallow lakes first developed in the Early Holocene under warmer and more humid conditions (Brenner et al, 1994; Curtis et al, 1998)
We identified and enumerated ostracode remains in previously unanalyzed samples from core PI-6 and together with previously analyzed pollen (Correa-Metrio et al, 2012a) quantified the effects of abrupt climate and environmental shifts on freshwater ostracode and terrestrial plant communities in northern Guatemala over the past 85 ka by estimating the magnitude and velocity of ecological change
Nine ostracode species were identified in core PI-6 from Lake Petén Itzá

Summary

Introduction

High-resolution continental paleoclimate/paleoenvironment data sets that extend into the Pleistocene are rare, especially from the northern neotropics, a region where shallow lakes first developed in the Early Holocene under warmer and more humid conditions (Brenner et al, 1994; Curtis et al, 1998). One exception is Lake Petén Itzá, northern Guatemala, from which an ∼400-ka continuous sediment record was collected in 2006 (Kutterolf et al, 2016). More than 1300 m of sediment was recovered from multiple holes at seven sites (PI-1, PI-2, PI-3, PI-4, PI-6, PI-7, and PI-9) (Mueller et al, 2010) (Fig. 1). Cite this article: Pérez L et al (2021). Ecological turnover in neotropical freshwater and terrestrial communities during episodes of abrupt climate change.

Methods

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Discussion

Conclusion