Effects of Abrupt Climate Change on Ice Age Ecosystem of Lake Petén Itzá and on Distribution Patterns of Ostracodes across the Yucatán Peninsula

来自古特马拉Petén Itzá湖85 ka的沉积物序列的结果显示，在Heinrich事件期间，新热带区的极端冷却高达10°C（Hodell等人，2012年），并建议约200万年的老沉积物部分的高气候敏感性。建议分析气候突变的后果，随着时间的推移，对水生生态系统的稳定性，从而历史上的半岛尤卡坦半岛介形虫作为模式生物指示剂相互联系的三个主要研究课题。（1）通过扩展现有的近期介形类训练集和改进水深和电导率的传递函数，定量评估过去200 ka的湖平面变化。(2)利用化石介形类组合重建晚更新世极端气候事件的超微结构及其对佩滕伊察湖水生生物多样性的影响;（3）利用形态学和分子生物学工具，通过综合分类学方法，评估淡水介形类作为模式生物的地理学、地理学和系统发育学。为了启动对Petén Itzá湖沉积物的研究工作，延伸到85 ka以上，建议为明尼苏达大学LacCore的Petén Itzá科学钻探项目组织一个岩心取样小组。这还将进一步加强与中美洲的合作，并为今后在朱宁湖（秘鲁）进行综合社区发展项目钻探和计划在查尔科湖（墨西哥盆地）开展的工作做好准备。

Results from a 85 ka old sediment sequence from Lake Petén Itzá, Gutemala, show extreme cooling of the Neotropics of up to 10°C during Heinrich Events (Hodell et al., 2012) and suggest high climate sensitivity for the older sediment sections of about 200 ka. It is proposed to analyze the consequences of abrupt climate change on the stability of aquatic ecosystems over time and consequently the historical biogeography of the Peninsula Yucatán by using ostracodes as model bioindicators interlinking three major research topics. A (1) quantitative assessment of lake level changes during the past 200 ka is targeted by expanding an existing trainingset of recent ostracodes and refining transfer functions for water depth and conductivity. (2) Fossil ostracode assemblages will be used to reconstruct the ultrastructure of Late Pleistocene climate extremes and their effects on aquatic diversity of Lake Petén Itzá, and (3) to assess biogeography, phylogeography and phylogeny of freshwater ostracodes as model organisms by integrative taxonomy using morphology and molecular tools. In order to initiate research efforts on Lake Petén Itzá sediments extending beyond 85 ka a core sampling party for the Petén Itzá Scientific Drilling Project at LacCore, University of Minnesota, is proposed. This will also further strengthen the collaboration with Central America and prepare for future ICDP-drilling in Lake Junin (Peru) and planned work on Lake Chalco (Mexico Basin).