"Paleoecology of alpine tundra and high elevation plant communities, refugia and landscapes of British Columbia"

“高山苔原和高海拔植物群落、不列颠哥伦比亚省的保护区和景观的古生态”

• 批准号: 90581-2012
• 负责人: Hebda, Richard
• 金额: $ 1.22万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569012
• 关键词: Paleoecology; alpine; tundra; elevation; plant

Geological, botanical and DNA evidence indicate that parts of British Columbia may have escaped the last glaciation, a key feature of the biogeography of North America. This proposal tests the hypothesis that today's high elevation species, alpine plant communities and landscapes persisted through the last glacial maximum in the region and gave rise to modern alpine and sub-alpine flora and ecosystems. The project will use pollen and spore and other paleoecological analyses of sediments from lake cores and recently discovered geological exposures to trace the history of plants and ecosystems through the interval of maximum cold on south Vancouver Island and in the Omineca Mountains of north central British Columbia. Sedimentary sequences will be dated by radiocarbon and optical dating. In addition the reflected infrared to visible light spectrum of samples from soil horizons will be used in combination with remnant landform indicators of past frigid climates to differentiate land surfaces covered by the most recent ice sheet from those glaciated in a more distant time. The results will shed light on the origin and history of modern high altitude ecosystems and their sensitivity to climate change. They will help explain the distribution of modern plant species and their genetic types in western North America and their relationships to Beringia and Asia. They will provide insight in to whether or not there was a barrier to human and animal migrations into North America late in the Pleistocene Epoch. The project will help develop methods for distinguishing landscapes arising from recent glaciations of different ages.

地质学、植物学和DNA证据表明，不列颠哥伦比亚省的部分地区可能逃过了最后一次冰川作用，这是北美地理学的一个关键特征。这项提议检验了这样一种假设，即今天的高海拔物种、高山植物群落和景观在该地区的最后一次盛冰期持续存在，并产生了现代高山和亚高山植物群和生态系统。该项目将利用花粉和孢子以及湖芯沉积物和最近发现的地质暴露的其他古生态学分析，追踪温哥华岛南部和不列颠哥伦比亚省中北部的奥米尼卡山脉最冷时期的植物和生态系统历史。沉积序列的年代测定将采用放射性碳和光学年代测定法。此外，将结合过去寒冷气候的残留地貌指标，使用土壤层样品的反射红外到可见光光谱，以区分最近冰盖覆盖的陆地表面和更遥远时期的冰川覆盖的陆地表面。研究结果将揭示现代高海拔生态系统的起源和历史及其对气候变化的敏感性。他们将有助于解释现代植物物种的分布和它们在北美西部的遗传类型，以及它们与白令海和亚洲的关系。他们将提供洞察是否有一个障碍，人类和动物迁移到北美晚更新世时代。该项目将帮助开发区分不同年龄的最近冰川形成的景观的方法。