Collaborative Research: RAPID: Mechanisms and fate of fire-induced carbonate formation in a cold desert ecosystem

合作研究：RAPID：寒冷沙漠生态系统中火引起碳酸盐形成的机制和命运

• 批准号: 2331817
• 负责人: David Huber
• 金额: $ 1.82万
• 依托单位: University of Texas at El Paso
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2331817&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Mechanisms; fate

Drylands have always been linked with wildfires, but climate change and shifts in vegetation have altered the fire regime and carbon balance of these sensitive ecosystems. Wildfires consume vegetation, releasing stored organic carbon as carbon dioxide (CO2), a greenhouse gas. Recently, however, the accumulation of salts in the form of soil carbonates (i.e., inorganic carbon) have been observed after dryland wildfires. The mechanisms of fire-induced carbonate accumulation (FICA) and its importance to long-term carbon storage remain unknown. This research begins to address a gap in our knowledge about the origin, fate, and impact of fire-induced soil carbonates as wildfire activity is at its historic highest levels in drylands. Here, researchers characterize the environmental controls on fire-induced carbonate accumulation using a prescribed rangeland fire slated for September 2023 in an already intensively instrumented catchment of the US Department of Agriculture’s Northwest Watershed Research Center (NWRC) and Critical Zone Observatory (CZO). The research is part of an interdisciplinary group of researchers and land managers collaborating to enhance understanding of wildland fires to create greater regional impact. This research will characterize the abiotic factors contributing to fire-induced carbonate accumulation (FICA) using an experimental fire in September 2023, located within the cold desert, sagebrush steppe ecosystem characteristic of southern Idaho and the surrounding region. A combination of factors including soil pH, calcium availability, soil carbon dioxide (CO2) concentration, and extracellular enzymatic activity appear to lead to FICA, but the exact mechanisms involved, and the source and fate of this carbon remain unresolved. Uncommon in rangeland wildfire studies, the project will 1) collect soil samples just before the fire, and contrast these with post-fire conditions to facilitate future investigation of controls on FICA, and 2) measure soil CO2, moisture, and temperature conditions before, during, and for 9 months after the fire – a unique and perishable dataset, and something that has never been done to study the mechanisms driving carbonate formation caused by fires. Sample collection and sensor measurements will be stratified across north- and south-facing aspects, and burn severity treatments (i.e., vegetation types) to understand landscape controls on FICA. Soil samples are also considered perishable and will be archived for future investigation beyond initial pH, EC, and carbonate determination.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.

旱地一直与野火联系在一起，但气候变化和植被变化改变了这些敏感生态系统的火灾状况和碳平衡，但最近野火消耗了植被，将储存的有机碳释放为二氧化碳（CO2），这是一种温室气体。旱地野火后观察到盐以土壤碳酸盐（即无机碳）形式积累，但火灾引起的碳酸盐积累（FICA）的机制及其对长期碳储存的重要性仍不清楚。这项研究开始解决我们对火灾引起的土壤碳酸盐的起源、命运和影响的认识空白，因为旱地的野火活动达到了历史最高水平。在这里，研究人员利用火灾引起的碳酸盐积累来描述环境控制。定于 2023 年 9 月在美国农业部西北流域研究中心 (NWRC) 和关键区域观测站 (CZO) 的一个已配备密集仪器的集水区发生预定的牧场火灾。该研究是跨学科小组的一部分。研究人员和土地管理者合作，加深对荒地火灾的了解，以产生更大的区域影响。这项研究将利用 2023 年 9 月位于寒冷沙漠鼠尾草草原内的一场实验火灾来描述导致火灾引起的碳酸盐积累 (FICA) 的非生物因素。爱达荷州南部及周边地区的生态系统特征，包括土壤 pH 值、钙有效性、土壤二氧化碳 (CO2) 浓度和细胞外酶活性等因素的组合似乎导致了 FICA，但所涉及的确切机制以及这种碳的来源和归宿在牧场野火研究中并不常见，该项目将 1) 在火灾发生前收集土壤样本，并将其与火灾后的情况进行对比，以促进未来对 FICA 控制的调查，以及 2) 测量土壤。火灾发生前、火灾期间和火灾后 9 个月的二氧化碳、湿度和温度条件——这是一个独特且易腐烂的数据集，也是研究火灾引起碳酸盐形成机制之前从未做过的事情。土壤样本也被认为是易腐烂的，将被存档以供未来除初始 pH、EC 和碳酸盐测定之外的调查。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。