RAPID: The effects of wildfire on an ecohydrological experiment and the role of abiotic drivers of resistance and resilience in sagebrush-steppe landscapes

快速：野火对生态水文实验的影响以及艾蒿草原景观中抵抗力和复原力的非生物驱动因素的作用

• 批准号: 2037660
• 负责人: Marie-Anne de Graaff
• 金额: $ 19.97万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-15 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2037660&HistoricalAwards=false
• 关键词: RAPID; effects; wildfire; ecohydrological; experiment

Wildfire frequency and intensity are rising across the western United States. In the Great Basin region, fire promotes invasion of non-native annual grasses that further perpetuate the fire cycle. Fire and plant invasion threaten the habitat of many native species, the productivity of grasslands, and human livelihood. Understanding how fire affects plant species, soil resources, and ecosystem recovery following fire remains limited. In the sagebrush steppe ecosystem of the western United States, identifying the plant, soil, and climate conditions that control post-fire recovery would help pinpoint what makes these ecosystems resilient or vulnerable to fire. This project will evaluate how differences in soil water and nutrient availability before a fire determine the balance of native and invasive plant species after a fire. The dynamics of soil nutrients and water might explain why some sites are more likely to become invaded than other sites. There are strong connections between the researchers and rangeland managers in the region. The knowledge acquired in this study will help inform our understanding of fire-prone grasslands in the western United States. This project will train several early-career researchers, including a postdoctoral associate and undergraduate students.This project will study a 25-year ecohydrological experiment in Idaho that manipulates moisture, soil depth, and plant community composition. The experiment burned in a large 2019 wildfire, providing a unique opportunity to test how pre-fire abiotic and biotic conditions influence the resistance to invasive species after wildfire. This experiment will test a key hypothesis about how non-native annual grasses invade native ecosystems. The expectation is that the primary establishment of non-native grasses causes further changes to the soil that change the ecosystem. To test this hypothesis, several measurements need to be made immediately during the initial vegetation recovery phase: (1) vegetation composition and cover, (2) soil water and nutrient availability and (3) soil water and nutrient movement. These immediate measurements will help understand what happens to soil nitrogen and water availability as bare soil is recolonized by plants. This will allow mechanistic insight into what drives differences in plant community recovery in sagebrush steppe ecosystems.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.

美国西部野火的频率和强度正在上升。在大盆地地区，火灾促进了非本地一年生草的入侵，进一步延续了火灾周期。火灾和植物入侵威胁着许多本地物种的栖息地、草原的生产力和人类的生计。了解火灾如何影响植物物种，土壤资源和火灾后的生态系统恢复仍然有限。在美国西部的山艾树草原生态系统中，确定控制火灾后恢复的植物，土壤和气候条件将有助于确定是什么使这些生态系统对火灾具有弹性或脆弱性。该项目将评估火灾前土壤水分和养分供应的差异如何决定火灾后本地和入侵植物物种的平衡。土壤养分和水分的动态可能解释了为什么某些地点比其他地点更容易受到入侵。研究人员和该地区的牧场管理者之间有着密切的联系。在这项研究中获得的知识将有助于我们了解美国西部易发生火灾的草原。该项目将培训几名早期职业研究人员，包括博士后助理和本科生。该项目将研究爱达荷州的一项为期25年的生态水文学实验，该实验控制水分、土壤深度和植物群落组成。该实验在2019年的一场大火中燃烧，提供了一个独特的机会来测试火灾前的非生物和生物条件如何影响野火后对入侵物种的抵抗力。这项实验将测试一个关于非本地一年生草如何入侵本地生态系统的关键假设。人们期望，非原生草的初步建立会导致土壤的进一步变化，从而改变生态系统。为了检验这一假设，需要在植被恢复初期立即进行几项测量：（1）植被组成和覆盖，（2）土壤水分和养分的有效性，（3）土壤水分和养分的移动。这些即时的测量将有助于了解当裸露的土壤被植物分解时，土壤氮和水的可用性会发生什么变化。这将使机械洞察是什么驱动的差异，在植物群落恢复山艾树草原生态系统。这一奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。