Collaborative Research: Integrating paleoecological analysis and ecological modeling to elucidate the responses of tundra fire regimes to climate change

合作研究：整合古生态分析和生态模型来阐明苔原火灾状况对气候变化的响应

• 批准号: 1023477
• 负责人: Feng Sheng Hu
• 金额: $ 68万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1023477&HistoricalAwards=false
• 关键词: Collaborative; Research; Integrating; paleoecological; analysis

Recent climate warming has resulted in profound environmental changes in the Arctic, including shrub-cover expansion, permafrost thawing, and sea-ice shrinkage. These changes foreshadow more dramatic impacts that will occur if the warming trend continues. Among the major challenges in anticipating these impacts are ?surprises? in system components that have remained relatively stable in the observational record (typically past few decades in arctic regions). Tundra burning is potentially one such component. Available evidence suggests that ongoing climate and vegetation change could significantly increase tundra burning. For example, preliminary findings reveal temperature and moisture thresholds, which may be crossed to result in burning rates that far exceed those witnessed in the observational record. In addition, a marked increase in shrub abundance is changing the physiognomic structure of arctic regions such that future tundra fire regimes may differ vastly from modern. Thus tundra burning is emerging as a key process in the rapidly changing Arctic, and knowledge of tundra fire-regime responses to climate change is essential for projecting Earth system dynamics, developing ecosystem management strategies, and preparing arctic residents for future change.The short duration of observational fire records, paucity of fire-history studies, and possibility of novel future climate and vegetation greatly hinder our ability to evaluate how tundra fire regimes may respond to future climate and vegetation change. Paleoecological analysis and ecological modeling circumvent these limitations and offer the only ways to acquire such information. This research takes advantage of the complementary properties of paleoecological and modeling approaches to (1) quantify historic climate-vegetation-fire relationships in the tundra ecosystems of the North American Arctic, (2) conduct multi-proxy analyses of lake sediments to reconstruct tundra fire regimes during periods of the late Glacial and Holocene with novel combinations of climate and vegetation, (3) reparameterize ALFRESCO, a landscape ecosystem model initially developed to study the response of subarctic vegetation to changes in climate and fire regimes, for predicting tundra fire regimes under the suite of IPCC climate scenarios for the 21st century, (4) modify ED, a state-of-the-art physiologically-based model for tundra ecosystem studies, and (5) couple ED with ALFRESCO to simulate carbon dynamics related to 21st-century shifts in tundra fire regimes. Each of these elements is at the forefront of ongoing research in the respective areas, and together they promise to substantially advance our knowledge of climate-vegetation-fire interactions of tundra ecosystems for the past, present, and future.The consequences of altered fire regimes in tundra ecosystems are rarely considered by the scientific community, largely because tundra fires occur infrequently on the modern landscape. Fire managers in the Arctic lack the most fundamental knowledge about the fire regimes of tundra ecosystems (e.g., fire return intervals) for the design and implementation of landscape-level fire and fuels management plans. This research addresses this issue directly. The prognostic simulations of the 21st century fire regime will provide information directly relevant to fire management planning and policy in Alaska. The researchers will collaborate with scientists from federal management agencies through this project. This partnership promotes an improved understanding of the range of past, present, and future climate-fire relationships by federal and state natural resource managers.

最近的气候变暖导致了北极的严重环境变化，包括灌木覆盖，多年冻土和海冰收缩。这些变化预示了如果变暖趋势继续下去，将会产生更大的影响。预期这些影响的主要挑战之一是惊喜吗？在观测记录中（通常在北极地区过去几十年）中，在系统组件中保持相对稳定。苔原燃烧可能是这样的组成部分。现有证据表明，持续的气候和植被变化可能会大大增加苔原燃烧。例如，初步发现揭示了温度和水分阈值，这可能会导致燃烧率远远超过观测记录中见证的速率。此外，灌木丰度的显着增加正在改变北极区域的polightomic构结构，以使未来的苔原消防方案可能与现代差异很大。因此，苔原燃烧正在成为北极快速变化的关键过程，并且对苔原消防对气候变化的反应的了解对于投射地球系统动态，制定生态系统管理策略以及为北极居民做准备以使未来的变化至关重要。观察性火灾记录，消防研究的匮乏以及新颖的未来气候和植被的可能性极大地阻碍了我们评估苔原火灾制度如何应对未来气候和植被变化的能力。古生态分析和生态建模规定了这些局限性，并提供获取此类信息的唯一方法。这项研究利用了（1）在北美北极的苔原生态系统中量化历史性气候 - 捕食关系的互补特性，（2）进行多型湖沉积物分析以构造tundra fire tundra fire在冰川和植被的新型组合的晚期冰川和全新世期间的制度，（3）重新聚集Alfresco，这是一种最初开发的景观生态系统模型IPCC气候场景套件21世纪，（4）修改ED，这是一种基于生理的最先进的苔原生态系统研究模型，（5）与Alfresco相对多一，以模拟与21st-的碳动态苔原消防方案的世纪变化。这些要素中的每一个都处于各个领域正在进行的研究的最前沿，并且他们共同承诺将大大提高我们对苔原生态系统在过去，现在和未来之间对气候绿化 - 互动相互作用的了解。改变消防制度的后果。在苔原中，科学界很少考虑生态系统，这主要是因为苔原大火很少发生在现代景观上。北极的消防员缺乏有关苔原生态系统的火灾制度（例如，消防返回间隔）的最基本知识，用于设计和实施景观级别的消防和燃料管理计划。这项研究直接解决了这个问题。 21世纪消防制度的预后模拟将提供与阿拉斯加消防管理计划和政策有关的信息。研究人员将通过该项目与来自联邦管理机构的科学家合作。该伙伴关系促进了联邦和州自然资源经理对过去，现在和未来气候火灾关系的范围的提高。