Testing for Climate-Induced Marine Community Change and Ecological Disruption at Mid-Latitudes during the Late Paleozoic Ice Age

气候引起的海洋群落变化和中纬度地区晚古生代冰期生态破坏的测试Matthew Clapham，加州大学圣克鲁兹分校的Matthew Clapham-0844383ABSTRACT了解生物对气候变化的反应是否趋向于渐进和可预测的，或者群落是否被破坏并在交替的州之间经历快速、大范围的转移是重要的。后一种情况将导致多样性大大减少，少数机会性类群占优势，生态系统不稳定。越来越多的证据表明，来自晚古生代冰河时代(约3亿年前)的陆地，可能还有海洋生物群落，在气候变化时期经历了快速的波动。玻利维亚北部出露的晚古生代沉积岩记录了从冰川冰库到非冰川温室世界的完全过渡，为测试气候对海洋生态系统的破坏提供了一个理想的深层档案。特别是，玻利维亚的这些地区在3亿年前位于亚热带纬度，这是一个关键地区，许多物种对不断变化的条件特别敏感。定量的古生态分析将比较120多个沉积层中每种化石类型的相对丰度，这些沉积层横跨冰川消融和冰川后气候变暖。使用该数据集的统计测试将能够识别社区组成的长期趋势，以及指示社区破坏的短期波动(如果存在)。这项研究的结果将有助于约束气候-生物圈相互作用的一般原则。

Testing for Climate-Induced Marine Community Change and Ecological disruption at Mid-Latitudes during the Late Paleozoic Ice AgeMatthew Clapham, University of California-Santa CruzEAR-0844383ABSTRACTIt is important to understand whether the biotic response to climate change tends to be gradual and predictable, or if communities are disrupted and undergo rapid, large-magnitude shifts between alternate states. The latter scenario would result in greatly reduced diversity, dominance of a few opportunistic taxa, and unstable ecosystems. There is mounting evidence from the late Paleozoic ice age (about 300 million years ago) that terrestrial, and possibly also marine communities, underwent rapid fluctuations during times of climate change. A complete transition from glaciated icehouse to non-glaciated greenhouse world is recorded in late Paleozoic sedimentary rocks exposed in northern Bolivia, providing an ideal deep-time archive in which to test for climate-induced disruption to marine ecosystems. In particular, the localities in Bolivia were located in subtropical latitudes 300 million years ago, a pivotal region where many species would have been especially sensitive to changing conditions. Quantitative paleoecological analysis will compare the relative abundance of each fossil type in more than 120 sedimentary layers spanning the interval of deglaciation and postglacial climate warming. Statistical tests using that dataset will enable recognition of both long-term trends in community composition and, if present, short-term fluctuations indicative of community disruption. The results from this research will help constrain the general principles of climate-biosphere interactions.