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

加拿大西部白垩纪和古近纪植被：有机体和植物区系的进化

• 批准号: 6908-2007
• 负责人: Stockey, Ruth
• 金额: $ 3.51万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=474182
• 关键词: Cretaceous; paleogene; vegetation; western; Canada

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.

白垩纪和古近纪见证了维管植物历史上最引人注目的区系演化。 在此期间，开花植物出现、多样化并占据主导地位。 蕨类植物和松科针叶树经历了显着的进化辐射。 许多其他类群，如蕨类植物和裸子植物，其多样性显着减少或类群灭绝。 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相关。 开花植物主导的森林取代了针叶树和苏铁树。 蕨类植物辐射到因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，主导了高地和干燥的栖息地。 森林地面上的草本地被发生了显着变化，苔藓植物、石松类和马尾类新物种的进化以及蕨类植物的爆炸性辐射表明了这一点。 随着年平均气温从热带条件下降，加拿大西部的气候发生了巨大变化。 阿尔伯塔省和不列颠哥伦比亚省特别适合研究这些变化，因为它们产生了北美最丰富的植物化石来源。 艾伯塔省中部和南部的压缩植物区系可以描述许多新物种、整个植物的重建以及植物区系生长和沉积环境中的特征描述。 解剖学上保存最壮观的植物化石来自世界著名的普林斯顿燧石，以及温哥华岛和太平洋沿岸碳酸盐海洋结核中的几个新化石来源。 我们将利用传统技术研究解剖学、形态学和系统发育，以及三维重建、落射荧光、CLSM、SEM 和 TEM 等新方法，研究多个地点的植物化石的演化。研究将集中于不列颠哥伦比亚省和艾伯塔省始新世森林的最后的前被子植物植被、早期被子植物植物区系以及火灾历史、水生植物区系以及果实和种子。