Arctic Observing Networks: Collaborative Research: ITEX AON - understanding the relationships between vegetation change, plant phenology, and ecosystem function in a warming Arctic

北极观测网络：合作研究：ITEX AON - 了解北极变暖中植被变化、植物物候和生态系统功能之间的关系

• 批准号: 1504381
• 负责人: Steven Oberbauer
• 金额: $ 37.15万
• 依托单位: Florida International University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-15 至 2022-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1504381&HistoricalAwards=false
• 关键词: Arctic; Observing; Networks; Collaborative; Research

Arctic ecosystems are changing in response to arctic warming, which is proceeding more than twice as fast as the global average. The International Tundra Experiment (ITEX) was established in the early 1990s to understand the effects of warming and environmental variability on tundra vegetation properties and ecosystem function. The ITEX program has been extremely valuable for detection of changes in tundra plant and ecosystem responses to experimental warming and to background climate change across sites that span the major ecosystems of the Arctic. In 2007, the Alaskan and Greenland ITEX sites were combined into an Arctic Observatory Network (AON). The current ITEX AON project will continue to document and understand Arctic terrestrial vegetation change and its ecosystem consequences by maintaining the long-term datasets of the ITEX-AON. The warming experiment of ITEX-AON allows us to assign the cause for observed changes in response to warming instead of relying on simple correlations. This project provides urgently needed data on changes in vegetation and the importance of these changes for ecosystem services from a variety of Arctic ecosystems. This project will provide training for postdoctoral, graduate and undergraduate students in the emerging fields of remote sensing, cybertechnology and big-data analysis. The project will include outreach activities through strong relationships with the CLEO Institute in Miami; the Grand Valley State University Regional Math and Science Center; and K-12 school systems in Miami, Anchorage, Grand Rapids and El Paso. All data from this project are and will be freely available at the NSF Arctic Data Center.The core datasets of the proposed research include manual observations of phenology, vegetation structure and composition, and ecosystem function (carbon flux and nutrient cycling) on long-term ITEX control and experimental warming plots, repeat measurement of vegetation plots on the long-term 1 km2 vegetation grids, and a multifactor warming/moisture experiment in Greenland. In 2009, the sampling scheme was expanded to include a larger spatial component to amplify the value of the measurements collected. This expansion included the addition of phenocams, automated mobile sensor platforms, and medium-scale aerial imagery. The automated platforms measure a suite of vegetation surface properties with minimal effort across focal transects spanning strong moisture and microtopographic gradients at a near-daily frequency. These measurements capture the fine-scale changes in vegetation over the growing season that are missed by lower frequency manual measurements and provide a bridge between manual measurements and aerial imagery. Medium-scale aerial imagery, using Kite Aerial or Unmanned Aerial Vehicles, is acquired throughout the growing season for scaling of manual and automated measurements; satellite imagery is referenced to medium-scale aerial imagery to aid scaling of responses to the regional level. In the newest phase of AON ITEX, we are particularly focused on understanding the relationship between landscape subsidence as a result of permafrost thaw and vegetation structure and function because of the potential for significant positive feedbacks to climate change.

北极生态系统正在随着北极变暖的响应而发生变化，北极变暖的速度是全球平均水平的两倍以上。国际苔原实验（ITEX）于1990年代初建立，以了解变暖和环境变异性对苔原植被特性和生态系统功能的影响。 ITEX计划对于检测苔原植物的变化以及对实验变暖的生态系统的变化以及对跨越北极主要生态系统的背景气候变化的反应非常有价值。 2007年，将阿拉斯加和格陵兰ITEX站点合并为北极天文台网络（AON）。 当前的ITEX AON项目将通过维护ITEX-AON的长期数据集来记录并了解北极陆地植被变化及其生态系统的后果。 iTex-aon的变暖实验使我们能够为响应变暖而不是依靠简单相关性的观察变化分配原因。 该项目提供了有关植被变化的急需数据，以及这些变化对各种北极生态系统的生态系统服务的重要性。 该项目将为新兴领域，Cyber​​technology和Big-Data分析的新兴领域的博士后，研究生和本科生提供培训。该项目将包括与迈阿密克莱奥研究所的牢固关系的外展活动；大谷州立大学区域数学和科学中心；以及迈阿密，安克雷奇，大急流城和埃尔帕索的K-12学校系统。该项目的所有数据均已并且将在NSF北极数据中心免费获得。拟议的研究的核心数据集包括对物候学，植被结构和组成的手动观察，以及生态系统功能（碳通量和营养循环）在长期ITEX ITEX控制和实验性热量上，对长期的植被绘制了长期的水分，并在长期进行了实验性测量。在格陵兰的实验。在2009年，扩展了采样方案，包括一个较大的空间成分，以扩大收集的测量值。这种扩展包括添加苯检察，自动移动传感器平台和中等尺度的空中图像。自动化平台测量了一套植被表面特性的套件，在几乎每天的频率下，跨越强水分和微观图梯度的焦点横断面的努力最少。这些测量值捕获了整个生长季节中植被的细小变化，这些变化被低频手动测量所遗漏，并提供了手动测量和空中图像之间的桥梁。在整个生长季节中，使用风筝航空或无人机的中等尺度空中图像，用于手动和自动测量的缩放；卫星图像被引用中等规模的空中图像，以帮助对区域水平的响应缩放。在AON ITEX的最新阶段，由于永久冻结和植被结构和功能，我们尤其专注于理解景观沉降之间的关系，因为有可能对气候变化产生重大积极反馈。