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异性，预计在未来二十年中会增加。 但是，了解草地对过去和未来气候变化的反应是相对原始的。 该研究项目的目的是开发一种方法来重建在沉积物中保存的花粉记录中的定量草地覆盖物。 该项目将采用耦合的经验和理论方法，为北美草地植被的定量重建奠定基础。 它将在堪萨斯州的弗林特山（Flint Hills）进行，这是美国原住民塔格拉斯大草原（Tallgrass Prairie）最大的连续性广阔，该项目具有三个主要目标。 第一个目标是确定草原中13种常见植物类型的花粉生产率。 这将通过从弗林特山丘中许多小池塘中保存在沉积物中，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。 计算机模型将校准花粉与植被之间的关系，这将对每种类型的草地植物产生花粉生产力的估计。 第二个目标是建立由沉积盆地花粉代表的草原植被的区域和局部空间尺度。 这是随着气候变化，随着时间的流逝，随着时间的流逝，提供对草地植物覆盖的空间估计的关键步骤。 该项目的最终目标是通过使用新来的花粉生产率估算来重建过去几十年的地区草原植被。 调查人员将从弗林特山（Flint Hills）的一个大湖中获得沉积物核心。 过去50年来的花粉组合将从沉积物中量化，从空中照片和遥感数据中，盆地周围的覆盖物也将进行量化。 总体而言，这项研究将改善对草地植被和气候如何相互作用的解释，以及它们将来可能如何相互作用。 随着人类对草地生物群落的压力的增加，这种知识变得越来越重要。 该项目的结果将有助于辨别草地成分和生产力如何应对过去的气候变化。 它还将产生有关该地区居民认为不希望的两种趋势的信息，木本植物扩张的原因以及与大气中的过敏性花粉相关的因素。 研究项目的很大一部分将培训本科生和研究生进行现场和实验室活动。 利用堪萨斯州立大学工程和科学计划女性开发的基础设施，研究人员将参加对科学感兴趣的K-12女孩的宣传。 该项目生成的数据将与北美花粉数据库共享，以供其他研究人员使用。