Collaborative Research: P2C2--Extending Tree-Ring Based Reconstructions of Atlantic Gulf Basin Hydroclimate over the Common Era Using Old-Growth Sinker Wood

合作研究：P2C2——使用古老的沉降木扩展大西洋湾盆地水文气候的树轮重建

• 批准号: 2202858
• 负责人: Matthew Therrell
• 金额: $ 11.67万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202858&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Extending; Tree

The general goal of the research is to collect old-growth bald cypress and longleaf pine samples from trees that were cut in the late 19th and early 20th century to extend existing bald cypress tree-ring chronologies over the full Common Era.Baldcypress is one of the key tree species for tree-ring based climate reconstruction in the southeastern United States (U.S.), because of its longevity and its distinct sensitivity to spring and summer precipitation variability. Even though it has widespread applications in regional and continental-scale high-resolution paleoclimate research, the full spatiotemporal extent of its dendroclimatic potential is yet to be explored. The lack of remnant old-growth bald cypress stands with long-lived trees, in particular, contributes to the dearth of millennium-length chronologies in the Atlantic Gulf Basin (AGB). In the 19th and 20th century, old-growth forests, including bald cypress and longleaf pine stands, throughout the AGB were excessively exploited for the booming construction industry and few forests survived. During this commercial exploitation period, many logs were lost, stuck in river bends, in transport from the swamp harvest location to the mill sites. A century later, caches of such long-lived ‘sinker wood’ can be found on the bottoms of many AGB rivers and slips, forming the only reliable source of old-growth timber and a unique source for expanding the spatiotemporal reach of AGB dendrochronology.The researchers aim to use the extended chronologies to develop regional and seasonal AGB hydroclimate reconstructions that span the entire Common Era (1CE-present). On the interannual to decadal time scales best captured by bald cypress-based reconstructions, summer AGB hydroclimate variability is primarily influenced by Atlantic Multidecadal Variability (AMV). The resulting AGB hydroclimate reconstruction will build upon existing reconstructions of past AMV in three important ways: (a) temporal extension, (b) spatial extension, and (c) sub-seasonal resolution. Common Era-length reconstructions could improve the understanding of the regional expression of past periods of global-scale climate variability, specifically the Late Antique Little Ice Age (ca. 536-660 CE) and the Roman Climate Optimum (ca. 300 BCE -400 CE). Moreover, AGB reconstructions would provide important anchor points in the subtropics, a region typically underrepresented in terrestrial proxy networks. Furthermore, by developing independent earlywood and latewood width chronologies, the research team plans to reconstruct AGB hydroclimate variability at sub-seasonal resolution, which can help improve the understanding of the dynamical nature of large-scale ocean-atmosphere forcing of climate.The potential Broader Impacts include greater understanding of water resources in the southeastern United States, support for a post-doctoral researcher, a project-based undergraduate research experience course at the University of Arizona aimed at attracting under-represented students to scientific research, and outreach and field trips to the for local schools.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该研究的总体目标是从 19 世纪末和 20 世纪初砍伐的树木中收集古老的秃柏和长叶松样本，以将现有的秃柏树年表扩展到整个公元纪元。秃柏是其中之一由于其寿命长且对春季和夏季降水变化具有明显的敏感性，因此它是美国东南部基于树轮的气候重建的关键树种。尽管其在区域和大陆尺度高分辨率古气候研究中的应用，其树状气候潜力的完整时空范围仍有待探索，尤其是缺乏残留的古老秃柏树和长寿树，导致了资源的匮乏。大西洋湾盆地 (AGB) 的千年年表 在 19 世纪和 20 世纪，古老的森林，包括秃柏和整个 AGB 地区的长叶松林因蓬勃发展的建筑业而被过度开发，在这个商业开发时期，许多原木在从沼泽采伐地运往工厂的过程中被卡在河湾中而丢失。后来，在许多 AGB 河流和滑坡的底部都可以找到这种长寿的“沉木”，形成了古老木材的唯一可靠来源，也是扩大时空范围的独特来源研究人员旨在利用扩展的年表来开发跨越整个公元纪元（1CE至今）的区域和季节性AGB水文气候重建，在基于秃柏的重建（夏季AGB）最好捕获的年际到年代际时间尺度上。水文气候变化主要受大西洋多年代际变化 (AMV) 的影响 由此产生的 AGB 水文气候重建将建立在三个重要的过去 AMV 的现有重建的基础上。方式：（a）时间延伸，（b）空间延伸，和（c）次季节分辨率重建可以提高对过去时期全球范围气候变化的区域表达的理解，特别是古代晚期。此外，小冰河时代（约公元 536-660 年）和罗马气候最佳时期（约公元前 300 年 - 公元 400 年），AGB 重建将为亚热带这一典型地区提供重要的锚定点。此外，通过独立的早材和晚材宽度年表，研究小组计划在次季节分辨率下重建AGB水文气候变化，这有助于提高对大规模海洋大气强迫的动力学性质的理解。潜在的更广泛影响包括对美国东南部水资源的更多了解、对博士后研究员的支持、亚利桑那大学旨在吸引更多人的基于项目的本科生研究体验课程该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。