Evaluating fire-induced dieback of Amazonian rainforest

评估火灾引起的亚马逊雨林枯死

• 批准号: NE/S01084X/1
• 负责人: Yadvinder Malhi
• 金额: $ 82.95万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FS01084X%2F1
• 关键词: Evaluating; fire; induced; dieback; Amazonian

Wildfires have become the new norm in many parts of the Amazonian humid forest, an ecosystem that did not co-evolve with this stressor. Large areas of previously undisturbed and human-modified forests are catching fire, jeopardising the future of the largest and most biodiverse tropical rainforest in the world, and potentially acting as a feedback that would further increase regional and global climate change. In recent dry years the extent of fire has greatly exceeded the rate of deforestation in the Brazilian Amazon. These fires result in in about half of the trees dying, and open up the forests to make them more vulnerable to subsequent fires.Despite the growing prevalence of Amazonian wildfires, we still have a very limited understanding of why these low intensity understorey fires cause such high rates of tree mortality, which species functional traits predict vulnerability or survival to these fires, what are the impacts of wildfires on the forest carbon balance and what are the patterns of taxonomic and functional recovery following a fire event. We propose a research plan to achieve major advances in our understanding of such wildfire impacts, including of the underlying mechanisms that cause both short-term and longer-term tree mortality. This work will be based at a field site in Santarem in Eastern Brazilian Amazonia, where we have collected several years of measurements of detailed vegetation ecology and carbon cycle tracking over a range of plots. These include a number of plots which experienced fire during the 2015/16 El Niño.We will implement this project by combining a state-of-the-art forest burn experiment with continued monitoring of a unique set of long-term sampling plots, some of which we have tracked through the 2015-16 wildfire event associated with a strong El Niño. We are uniquely placed to address these fundamental questions given our network of burned and unburned forest plots that is already in place, the strong partnerships we have forged with park managers and federal agencies, and the numerous past datasets that we can use as baseline information. The fire experiment will involve setting fire to limited patch of forest (with the close cooperation of local fire brigades), tracking fire intensity and tracking the physiology and mortality responses of individual trees in the fire plots, including trees that have their root mats or their bark insulated from fire damage. We will also experiment with different fire break methodologies to explore the most effective way to stop such fires. With the intensive carbon cycle studies we will track the carbon cycle responses for up to seven years after the 2015 fires, giving us novel insight into the longer term carbon cycle responses and the ecosystem responses and recovery after a fire event.As well as advancing scientific knowledge about a pervasive and increasing threat to the future of tropical forests in the Anthropocene, our co-designed pathways to impact ensures we will also inform and improve approaches to minimise risk of fire-induced dieback of humid Amazonian forests. We will work closely with local fire managers, and engage with state and national policymakers, to draft recommendations on how to manage forest reserves and forest-agriculture mixed landscapes to minimise the risk of fire spread. If applied at a large scale, these fire prevention strategies are a crucial tool that can help minimise the risk of extensive fire-induced dieback within Amazonian forests.

野火已成为亚马逊潮湿森林许多地区的新常态，这种生态系统并没有与这种压力源共同进化。大面积以前未受干扰和人为改造的森林正在着火，危及世界上最大和最具生物多样性的热带雨林的未来，并可能成为进一步加剧区域和全球气候变化的反馈。在最近干旱的几年里，巴西亚马逊地区的火灾程度大大超过了森林砍伐的速度。这些火灾导致大约一半的树木死亡，并打开森林，使它们更容易受到后续火灾的影响。尽管亚马逊野火越来越普遍，我们仍然对为什么这些低强度的林下火灾导致如此高的树木死亡率了解非常有限，哪些物种的功能特征预测了这些火灾的脆弱性或存活率，野火对森林碳平衡的影响是什么，火灾事件后分类和功能恢复的模式是什么。我们提出了一项研究计划，以实现我们对这种野火影响的理解的重大进展，包括导致短期和长期树木死亡的潜在机制。这项工作将基于在巴西亚马逊河流域东部的桑塔雷姆，在那里我们已经收集了几年的详细植被生态和碳循环跟踪测量范围内的地块。我们将通过将最先进的森林燃烧实验与持续监测一组独特的长期采样地块相结合来实施该项目，其中一些我们已经跟踪了2015-16年与强厄尔尼诺相关的野火事件。鉴于我们已经建立的烧毁和未烧毁的森林地块网络，我们与公园管理者和联邦机构建立的强大伙伴关系，以及我们可以用作基线信息的众多过去数据集，我们处于独特的位置来解决这些基本问题。火灾实验将涉及在有限的森林中放火（与当地消防队密切合作），跟踪火灾强度，并跟踪火区中个别树木的生理和死亡反应，包括根垫或树皮免受火灾损害的树木。我们还将尝试不同的防火方法，以探索阻止此类火灾的最有效方法。通过深入的碳循环研究，我们将跟踪2015年火灾后长达七年的碳循环响应，为我们提供更长期的碳循环响应以及火灾事件后生态系统的响应和恢复的新见解。同时，我们还将推进关于人类世热带森林未来面临的普遍和日益增长的威胁的科学知识，我们共同设计的影响途径确保我们还将提供信息并改进方法，以最大限度地减少亚马逊潮湿森林火灾引发的枯死风险。我们将与当地火灾管理人员密切合作，并与州和国家政策制定者合作，就如何管理森林保护区和森林-农业混合景观起草建议，以最大限度地降低火灾蔓延的风险。如果大规模应用，这些防火策略是一个至关重要的工具，可以帮助减少亚马逊森林内大规模火灾引起的枯死的风险。

项目成果

Functional susceptibility of tropical forests to climate change

• DOI: 10.1038/s41559-022-01747-6
• 发表时间: 2022-05
• 期刊: Nature Ecology & Evolution
• 影响因子: 16.8
• 作者: J. Aguirre‐Gutiérrez;E. Berenguer;Imma Oliveras Menor;D. Bauman;J. Corral-Rivas;M. G. Nava-Miranda

El Niño impacts on human-modified tropical forests: Consequences for dung beetle diversity and associated ecological processes

厄尔尼诺现象对人类改造热带森林的影响：粪甲虫多样性和相关生态过程的后果

• DOI: 10.1111/btp.12756
• 发表时间: 2020
• 期刊: Biotropica
• 影响因子: 2.1
• 作者: França F

Tracking the impacts of El Niño drought and fire in human-modified Amazonian forests.

• DOI: 10.1073/pnas.2019377118
• 发表时间: 2021-07-27
• 期刊: Proceedings of the National Academy of Sciences of the United States of America
• 影响因子: 11.1
• 作者: Berenguer E;Lennox GD;Ferreira J;Malhi Y;Aragão LEOC;Barreto JR;Del Bon Espírito-Santo F;Figueiredo AES;França F;Gardner TA;Joly CA;Palmeira AF;Quesada CA;Rossi LC;de Seixas MMM;Smith CC;Withey K;Barlow J
• 通讯作者: Barlow J