Cretaceous and paleogene vegetation of western Canada: organismal and floristic evolution

白垩纪和古近纪见证了维管植物历史上最戏剧性的植物区系演变。在此期间，开花植物出现、多样化并上升为优势。许多菲律宾蕨类和松科针叶植物经历了显著的进化辐射。但许多其他类群，如蕨类植物和裸子植物，多样性显著减少或分类群灭绝。进化更替伴随着物种丰富度的急剧增加，与生态复杂性的增加有关。开花植物取代了针叶树和苏铁在森林中占据主导地位。针叶蕨类植物辐射到由于植物群落复杂性增加而产生的生态位中。松科针叶树多样化，主导山地和更干燥的生境。在森林地面上，草本植物地面盖度发生了显著变化，从苔藓植物、番茄和马尾草新物种的进化可以看出，以及蕨类植物的爆炸性辐射。随着热带条件下年平均气温的下降，加拿大西部的气候发生了戏剧性的变化。加拿大阿尔伯塔省和不列颠哥伦比亚省是唯一适合研究这些变化的地方，因为它们产生了北美最丰富的植物化石来源。阿尔伯塔省中部和南部的压缩植物群允许描述许多新物种，完整的植物重建，以及在它们的生长和沉积环境中描述植物区系的特征。最壮观的解剖保存下来的化石植物来自世界著名的普林斯顿Chert，以及来自温哥华岛和太平洋海岸的碳酸盐海洋结核中的几个新的化石来源。*使用传统技术来研究解剖和沉积环境形态和系统发育，以及更新的三维重建、荧光、激光共聚焦显微镜、扫描电子显微镜和透射电子显微镜的方法，我们将研究一些地点的植物化石的进化。研究将集中在不列颠哥伦比亚省和艾伯塔省始新世森林中最后的前被子植物植被、早期被子植物植物群和火灾、水生植物群以及果实和种子的历史。

The Cretaceous and Paleogene witnessed the most dramatic floristic evolution in the history of vascular plants.  During this time flowering plants appeared, diversified and rose to dominance.  Filicalean ferns and pinaceous conifers underwent significant evolutionary radiations.  Many other groups such as pteridophytes and gymnosperms suffered significant reductions in diversity or taxa became extinct.  Evolutionary turnover was accompanied by a dramatic increase in species richness, correlated with an increase in ecological complexity.  Flowering plant dominated forests replaced conifers and cycads.  Ferns radiated into niches produced by increased complexity of plant communities.  Pinaceous conifers diversified to dominate upland and drier habitats.  On the forest floor there was significant change in herbaceous ground cover as seen by the evolution of new species of bryophytes, lycopods and horsetails, and an explosive radiation of ferns.  Climate of western Canada changed dramatically as mean annual temperatures decreased from tropical conditions.  Alberta and BC are uniquely suited for studying these changes because they yield some of the most abundant sources of plant fossils in North America.  Compression floras of central and southern Alberta allow description of many new species, whole plant reconstructions and characterization of floras in the context of their environments of growth and deposition.  The most spectacular occurrences of anatomically preserved fossil plants are from the world famous Princeton Chert and several new sources of fossils in carbonate marine nodules from Vancouver Island and the Pacific coast.  Using traditional techniques to study anatomy, morphology, and phylogeny, as well as newer methods for three-dimensional reconstruction, epifluorescence, CLSM, SEM, and TEM, we will investigate the evolution of fossil plants from a number of sites. Studies will center on the last pre-angiospermous vegetation, early angiospermous floras and the history of fires, aquatic floras, and fruits and seeds of Eocene forests from British Columbia and Alberta.