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.

中文翻译：

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气候突变期间新热带淡水和陆地群落的生态更新

过去 85,000 年的特点是尤卡坦半岛气候和环境的高度变化。Heinrich stadials 是气候突变的例子，涉及区域温度和水分可用性的变化。因此，它们作为自然实验来评估水生和陆地生态系统的对比反应。我们使用保存在从危地马拉 Petén Itzá 湖回收的 75.9 米长的沉积物核心（PI-6，~85 ka）中保存的介形虫和花粉来评估社区反应的幅度和速度。Ostracodes 对水温和电导率的变化很敏感。植被对温度的变化和蒸发与降水的比率作出反应。Ostracodes 显示出比植被更大、更快的群落变化。Heinrich Stadial 5-1 (HS5-1) 寒冷干燥，与较低的介介和植被物种丰富度和多样性有关。相比之下，HS6 和 HS5a 期间稍微温暖和干燥的条件反映在更高的介形虫物种丰富度和多样性上。我们的古生态学研究表明介形虫的最大生态周转发生在 62.5 到 51.0 ka 之间；对于花粉，它处于更新世/全新世过渡时期。未来的研究应利用湖泊和海洋沉积物记录中的各种气候和环境指标，进一步探索北部新热带地区晚冰期古气候的成因和影响。我们的古生态学研究表明介形虫的最大生态周转发生在 62.5 到 51.0 ka 之间；对于花粉，它处于更新世/全新世过渡时期。未来的研究应利用湖泊和海洋沉积物记录中的各种气候和环境指标，进一步探索北部新热带地区晚冰期古气候的成因和影响。我们的古生态学研究表明介形虫的最大生态周转发生在 62.5 到 51.0 ka 之间；对于花粉，它处于更新世/全新世过渡时期。未来的研究应利用湖泊和海洋沉积物记录中的各种气候和环境指标，进一步探索北部新热带地区晚冰期古气候的成因和影响。