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演化

• 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: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=364668
• 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.

白垩纪和古近纪是维管植物历史上最剧烈的植物区系演化时期，在这一时期出现了开花植物，在进化过程中，蕨类植物和松柏类植物经历了显著的进化辐射。许多其他类群如蕨类植物和裸子植物的多样性显著减少或灭绝。进化更替伴随着物种的急剧增加。物种丰富度，与生态复杂性的增加相关。开花植物占主导地位的森林取代了针叶树和苏铁。蕨类植物辐射到植物群落复杂性增加产生的生态位中。松科针叶树多样化，占主导地位的高地和干燥的栖息地。在森林地面上，草本地被发生了显着变化，表现为新物种的进化，如石松属，石松属和木贼属，和蕨类植物的爆发性辐射。加拿大西部的气候随着年平均气温从热带条件下降而发生了剧烈的变化。阿尔伯塔和不列颠哥伦比亚省是研究这些变化的唯一合适地区，因为它们产生了北美最丰富的植物化石来源。阿尔伯塔中部和南部的压缩植物群允许描述许多新物种，在植物生长和沉积环境的背景下，对植物群进行全植物重建和特征描述。最壮观的解剖学保存的植物化石来自世界著名的普林斯顿燧石和温哥华岛碳酸盐海洋结核中的几个新化石来源，以及使用传统的技术来研究解剖学，形态学和植物发生学，以及三维重建，荧光，CLSM，SEM和TEM的新方法，我们将调查来自一些地点的化石植物的进化。研究将集中在最后的前被子植物植被，早期被子植物区系和火灾的历史，水生植物区系，以及来自不列颠哥伦比亚省和阿尔伯塔始新世森林的果实和种子。