Improving Reconstructions of Open Vegetation in North America: Pollen-Productivity Estimates for Grassland Plants

改善北美开放植被的重建：草原植物的花粉生产力估算

• 批准号: 0821959
• 负责人: Kendra McLauchlan
• 金额: $ 9万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0821959&HistoricalAwards=false
• 关键词: Improving; Reconstructions; Open; Vegetation; North

The Great Plains of the U.S. experience remarkable climate variability that is projected to increase in the next two decades. Knowledge of grassland response to past and future climate changes is relatively primitive, however. The purpose of this research project is to develop a method to reconstruct quantitative grassland cover from pollen records preserved in sediment. The project will employ a coupled empirical and theoretical approach to lay the foundation for quantitative reconstructions of grassland vegetation in North America. It will be conducted in the Flint Hills of Kansas, the largest contiguous expanse of native tallgrass prairie in the U.S. The project has three main goals. The first goal is to determine pollen productivity for 13 common plant types in the grassland. This will be accomplished by obtaining pollen preserved in sediment from many small ponds in the Flint Hills and conducting detailed vegetation surveys around each pond where pollen is collected. A computer model will calibrate the relationships between pollen and vegetation, which will produce an estimate of pollen productivity for each type of grassland plant. The second goal is to establish both the regional and local spatial scales of grassland vegetation represented by pollen in sedimentary basins. This is a key step to providing spatially explicit estimates of the cover of grassland plants over time as climate changes. The final goal of the project is to reconstruct regional grassland vegetation for the past several decades by using the newly-derived pollen productivity estimates. The investigators will obtain a sediment core from a large lake in the Flint Hills. Pollen assemblages from the past 50 years will be quantified from the sediments, as will land cover surrounding the basin from aerial photos and remote sensing data. Overall, this research will improve interpretations of how grassland vegetation and climate have interacted in the past and how they are likely to interact in the future. This knowledge is becoming more important as human pressure on the grassland biome increases.Much of the economy of the Great Plains of the U.S. depends on grassland resilience to climate variability. The results of this project will help discern how grassland composition and productivity have responded to past climate changes. It also will produce information about two trends perceived as undesirable by residents of the region, the causes of woody plant expansion and the factors correlated with allergenic pollen in the atmosphere. A significant portion of the research project will train undergraduate and graduate students to conduct field and laboratory activities. Using infrastructure developed by Kansas State University's Women in Engineering and Science Program, researchers will take part in outreach to K-12 girls interested in science. Data generated by the project will be shared with the North American Pollen Database for use by other researchers.

美国的大平原经历了显着的气候变化，预计在未来二十年将增加。 然而，关于草地对过去和未来气候变化的响应的知识相对原始。 本研究项目的目的是开发一种方法来重建定量草原覆盖从沉积物中保存的花粉记录。 该项目将采用经验和理论相结合的方法，为北美草原植被的定量重建奠定基础。 它将在堪萨斯的弗林特山进行，这是美国最大的本土高草草原。 第一个目标是确定花粉生产力的13个常见的植物类型在草原上。 这将通过获取保存在弗林特山许多小池塘沉积物中的花粉，并在收集花粉的每个池塘周围进行详细的植被调查来实现。 一个计算机模型将校准花粉和植被之间的关系，这将产生每种类型的草原植物花粉生产力的估计。 第二个目标是建立沉积盆地中以花粉为代表的草原植被的区域和局部空间尺度。 这是一个关键步骤，提供空间上明确的估计覆盖草地植物随着时间的气候变化。 该项目的最终目标是通过使用新获得的花粉生产力估计来重建过去几十年的区域草地植被。 调查人员将从弗林特山的一个大湖中获得沉积物岩心。 将从沉积物中量化过去50年的花粉组合，以及从航空照片和遥感数据中量化盆地周围的土地覆盖物。 总的来说，这项研究将改善对草原植被和气候在过去如何相互作用以及它们在未来如何相互作用的解释。 随着人类对草原生物群落的压力越来越大，这方面的知识变得越来越重要。美国大平原的大部分经济都依赖于草原对气候变化的适应能力。 该项目的结果将有助于了解草地组成和生产力如何对过去的气候变化作出反应。 它还将提供有关该地区居民认为不受欢迎的两种趋势的信息，即木本植物扩张的原因和与大气中过敏性花粉相关的因素。 该研究项目的一个重要部分将培训本科生和研究生进行实地和实验室活动。 研究人员将利用堪萨斯州立大学妇女工程和科学项目开发的基础设施，参与对科学感兴趣的K-12女孩的外联活动。 该项目产生的数据将与北美花粉数据库共享，供其他研究人员使用。