Collaborative Research: Global Phytogeography of the Early/Late Carboniferous Boundary Based on Spores and Pollen

小行星9418424 古植物地理学研究古代陆地植物的分布，有助于我们了解古代气候变化的性质以及气候变化如何影响陆地植物多样性。 古植物地理学研究的数据来自两个来源：大花组合（化石叶，茎，种子和其他植物部分的积累）和孢子花粉组合。 与大花组合相比，孢子花粉组合更容易分配到狭窄的地质时间间隔，具有较高的属和物种多样性，并可能来自更广泛的栖息地（特别是更干旱的栖息地）。 这些因素表明，孢子花粉数据应产生详细和准确的植物地理学，然而，孢子花粉和大花植物地理学的研究在同一时间段很少产生一致的结果。 该提案寻求资金，以编制一份中石炭世（333至315 Ma）孢子花粉数据库，确定并应用适当的多元统计技术（包括Raup-Crick概率相似性指数、聚类分析和排序技术，如多维标度和倒数平均分析），用于孢子花粉数据的植物地理学分析，完成中石炭世真角石、同角石、网角石和Cancelloceras（G1）-角石带（纳穆里期A ~ C）的植物地理学研究。 完成这项工作将需要详细了解北美的孢子花粉组合在石炭纪中期。 因此，从中石炭纪的肯塔基州，亚拉巴马，犹他州，也许内华达州的孢子花粉组合将被收集，研究，并描述作为本项目的一部分。 这将导致在中石炭纪期间北美的孢子-花粉生物地层分带得到改善，并改善该区间的全球对比。 研究区间包括早/晚Caroniferous边界和一致的Laurussia-Gondwana碰撞，以及在南半球的冰川开始，高纬度冷却在北方和南半球，也许中纬度和赤道气候变化以及。 研究结果将确定赤道和中纬度气候变化的性质和时间，深入了解由于冰川爆发和/或大陆碰撞而导致的赤道和干燥中纬度植物群落的发展，并记录冰川作用和大陆碰撞对陆地植物多样性的影响。

9418424 Raymond Paleophytogeography, the study of the distribution of ancient land plants, helps us to understand the nature of ancient climate change and how climate change affects land-plant diversity. The data for paleophytogeography studies come from two sources: macrofloral assemblages (accumulations of fossil leaves, stems, seeds and other plant parts) and spore-pollen assemblages. Compared to macrofloral assemblages, spore-pollen assemblages are easier to assign to narrow intervals of geologic time, have higher generic and species diversity, and may derive from a wider range of habitats (particularly more arid habitats). These factors suggest that spore-pollen data should yield detailed and accurate phytogeographies; however studies of spore-pollen and macrofloral phytogeography for the same interval seldom produce congruent results. This proposal seeks funding to compile a mid-Carboniferous (333 to 315 Ma) spore-pollen database, identify and apply appropriate multivariate statistical techniques (including the Raup-Crick probabilistic similarity index, cluster analysis, and ordination techniques such as multidimensional scaling and reciprocal averaging analysis) for the phytogeographic analysis of spore-pollen data, and to complete phytogeographic studies of the mid-Carboniferous Eumorphoceras-, Homoceras-, Reticuloceras-, and Cancelloceras (G1)-goniatite zones (Namurian A through C). Completion of this work will require detailed knowledge of North American spore-pollen assemblages during the mid-Carboniferous. Thus, spore-pollen assemblages from the mid-Carboniferous of Kentucky, Alabama, Utah, and perhaps Nevada will be collected, studied, and described as a part of this project. This will result in an improved spore-pollen biostratigraphic zonation for North America during the mid-Carboniferous, and improved global correlation for this interval. The study interval includes the Early/Late Caroniferous boundary and coincides with the Laurussia-Gondwana collision as well as glacial onset in the Southern Hemisphere, high-latitude cooling in the Northern and Southern Hemispheres, and perhaps mid-latitude and equatorial climate change as well. The results will establish the nature and timing of equatorial and mid-latitude climate change, yield insight into the development of ever-wet, ever-warm equatorial and dry mid-latitude floral communities as a result of glacial onset and/or continental collision, and document the effect of glaciation and continental collision on land-plant diversity.