"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: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=506801
• 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、植物学和DNA证据表明，不列颠哥伦比亚省的部分地区可能已经逃过了最后一次冰川，这是北美生物地理的一个关键特征。这一建议验证了一种假设，即今天的高海拔物种、高山植物群落和景观持续到该地区最后一次冰川盛期，并产生了现代高山和亚高山植物和生态系统。该项目将利用对湖心沉积物的花粉、孢子和其他古生态分析，以及最近发现的地质暴露，追踪温哥华岛南部和不列颠哥伦比亚省中北部奥米内卡山脉最冷时期的植物和生态系统的历史。沉积层序将通过放射性碳测年和光学测年来确定。此外，还将结合过去寒冷气候的残存地貌指标，利用土壤层样本的红外到可见光反射光谱来区分最近冰盖覆盖的陆地表面和较远时间的冰川覆盖的陆地表面。这一结果将有助于揭示现代高海拔生态系统的起源和历史，以及它们对气候变化的敏感性。它们将有助于解释现代植物物种在北美西部的分布及其遗传类型，以及它们与贝林贾和亚洲的关系。他们将提供关于更新世晚期是否存在人类和动物迁徙到北美的障碍的洞察。该项目将有助于开发区分不同时代最近冰川产生的景观的方法。