COLLABORATIVE RESEARCH: Tropical Vegetation during the Early Part of an Ice Age: An Intercontinental Comparison of Mid-Carboniferous Floras in their Geochronologic Setting

合作研究：冰河时代早期的热带植被：中石炭世植物区系在其地质年代学背景下的洲际比较地球历史记录了主要的气候间隔，可以概括为全球温暖或寒冷。从最广泛的意义上说，向全球寒冷地球的过渡，代表着冰河时代的开始，自陆地生态系统建立以来，只发生过几次，例如在石炭纪和晚第三纪（在我们当前寒冷气候阶段的开始）。在这样的过渡时期，预计所有环境和所有尺度上的植物区系都将发生重大变化。本项目主要研究石炭世冰期初期，直至中石炭世边界（320 Ma）之后的热带陆生植物区系的变化。来自美国、波兰和捷克共和国煤盆地的含化石植物的岩石提供了非常完整的地层学大植物群和微植物群数据集，这些数据集是几十年来从煤上覆的岩石（大植物群）和煤本身（微生物群）中收集的。此外，在一些剖面内发现了火山成因的火山灰凝灰岩，提供了可以提供同位素年龄的矿物，从而可以控制盆地内部和盆地与世界其他地区之间的生物地层对比。根据这些未发表的数据和支持收集的资料，将建立植被变化的标准参考剖面，以记录分类学更替的速率。这些数据将允许对热带植被群落变化的地理范围和优势多样性程度进行定量分析。这个项目的结果可以作为我们当前冰河期类似间隔研究的基线。

Collaborative Research: Tropical Vegetation during the Early Part of an Ice Age: An Intercontinental Comparison of Mid-Carboniferous Floras in their Geochronologic SettingRobert GastaldoEAR-0207359ABSTRACTEarth history records major climatic intervals that can be generalized as either globally warm or cold. Transitions to a globally cold Earth, representing the onset of an ice age in the broadest sense, has happened only a few times since the establishment of terrestrial ecosystems, for instance in the Carboniferous and Late Tertiary (at the beginning of our current cold climate phase). At such times of transition, there are expected to be significant changes in the flora in all environments and at all scales. This project focuses on the changes in tropical terrestrial floras during the initial phases of the Carboniferous ice age, up to and immediately after the Mid-Carboniferous boundary (320 Ma). Fossilplant-bearing rocks from coal basins in the United States, Poland, and the Czech Republic provide remarkably stratigraphically complete macrofloral and microfloral data sets, which have been collected for decades from rocks overlying the coals (macroflora) and the coals themselves (microflora). Additionally, volcanogenic ash-fall tuffs have been identified within some sections, providing minerals that can provide isotopic ages, permitting control of biostratigraphic correlations within and between the basins and other parts of the world. From these unpublished data and the supporting collections, astandard reference profile of vegetational changes will be established that will document the rates of taxonomic turnover through time. These data will allow for a quantitative analysis of the geographical extent and dominance-diversity magnitude of vegetational community changes in the tropics. Results from this project can serve as a baseline for the study of similar intervals in our current ice age.