FAPESP - Amazon PyroCarbon: Quantifying soil carbon responses to fire and climate change

FAPESP - Amazon PyroCarbon：量化土壤碳对火灾和气候变化的反应

• 批准号: NE/W001691/1
• 负责人: Ted Feldpausch
• 金额: $ 83.21万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW001691%2F1
• 关键词: FAPESP; Amazon; PyroCarbon; Quantifying; soil

Wildfires are becoming the new normal across Amazonia. Deforestation is transforming the region at a rate of around 10,000 square km/year (half the area of Wales), and now the area degraded annually -forest logged and burned but not cut down-is greater than the area deforested. Fire has historically been rare in Amazonia, meaning that the forests are not adapted to fire and the trees often die from fires - releasing carbon (C) back to the atmosphere and amplifying global climate change. Burning of tropical forests is already releasing more climate-warming carbon dioxide than fossil fuel burning in the whole of Europe. Trees in Amazonia contain around 7x more C than humans are releasing every year, and soils contain the same amount again, so it is vital to understand what is happening to this C and minimize emissions. As vegetation sheds its leaves, branches, and roots, or dies, some of the C released remains in the soil, and some is later decomposed and released back to the atmosphere. Carbon exists in the soil in many different forms, from new inputs from decomposing plant material to ancient C formed over millennia. Burning adds pyrogenic carbon (PyC) to the soil, a partially burnt form of C that is resistant to decomposition and could make the soil more fertile. Because soil C takes a long time to form, its conservation is particularly important. Despite the widespread increase in fire in Amazonia, there have been few measurements of soil C fractions and dynamics in burned areas - most have focussed on natural forests. Burned forests will have different composition, forest structure, and C dynamics. Understanding how different soil C fractions are formed and lost is crucial to understand how fire and climate change affect C storage. We propose to make major advances in understanding fire impacts, including the processes that affect the type and quantifies of soil C formed, and how C gains/losses vary over time, with soil type, and climate. We will combine new measurements with innovative modelling to inform land management strategies and C budgets.We have already collected data from across Amazonia in intact forests that have not recently burned. Crucially our project will collect a new, comprehensive dataset from human-modified forests, including logged, burned and abandoned land. We will use an approach known as a chronosequence, where we take samples at sites that were burnt at different times in the past, so we can see how the soil C has changed after e.g. 1 year, 2 years, or up to 20 years after a fire. This will then be used to develop a state-of-the-art land surface model, JULES, which forms part of the UK Earth System Model. At our sample sites, we will evaluate how different burn severities affect soil C, both in surface and deep soils, and how these change over time post-burning and with soil, climate, and land-use such as logging. At 3 focal sites, we will take detailed measurements of the decomposition rate of the C over 4 years, comparing measurements with different land-use, burn severity and wet vs dry seasons. Knowing what forms C takes after a fire and how fast it decomposes under different conditions will enable us to build these processes into the JULES model. We will model PyC globally for the first time and make projections of land C changes in Amazonia over the next ~40-60 years under different management practices. As well as transforming scientific understanding of post-fire soil C and its resilience to climate and management, our project will inform socio-environmental planning for sustainable resource use to conserve soil C. We will work with regional partners, fire managers, state and national policymakers to integrate our findings into decision-making to minimise negative fire impacts. Due to the Amazon Basin-scale of our work, these strategies are a crucial step to limit the risk of large-scale loss of soil C.

野火正在成为亚马逊地区的新常态。森林砍伐正在以每年约1万平方公里（威尔士面积的一半）的速度改变着该地区，现在该地区每年都在退化——森林被砍伐和焚烧，但没有砍伐——比森林被砍伐的面积更大。亚马逊地区历史上很少发生火灾，这意味着森林不适应火灾，树木经常死于火灾，将碳(C)释放回大气，加剧了全球气候变化。燃烧热带森林已经释放出比整个欧洲燃烧化石燃料更多的导致气候变暖的二氧化碳。亚马逊地区的树木所含的碳比人类每年释放的碳多7倍左右，而土壤所含的碳又相同，因此了解这些碳的变化并最大限度地减少排放至关重要。当植物的叶子、树枝和根脱落或死亡时，释放的一些碳留在土壤中，一些随后被分解并释放回大气中。碳以多种不同的形式存在于土壤中，从分解植物材料的新输入到几千年来形成的古老碳。燃烧将热原碳（PyC）添加到土壤中，这是一种部分燃烧的碳，不易分解，可以使土壤更肥沃。因为土壤C需要很长时间才能形成，所以它的保存尤为重要。尽管亚马逊地区的火灾普遍增加，但很少有对被烧毁地区的土壤C组分和动态的测量——大多数都集中在天然林上。燃烧后的森林会有不同的成分、森林结构和碳动态。了解不同土壤C组分是如何形成和损失的，对于了解火灾和气候变化如何影响C储存至关重要。我们建议在理解火灾影响方面取得重大进展，包括影响土壤C形成的类型和数量的过程，以及C的收益/损失如何随时间、土壤类型和气候而变化。我们将把新的测量方法与创新模型结合起来，为土地管理策略和碳预算提供信息。我们已经收集了亚马逊地区未被烧毁的完整森林的数据。至关重要的是，我们的项目将从人类改造的森林中收集一个新的、全面的数据集，包括砍伐、烧毁和废弃的土地。我们将使用一种被称为时间序列的方法，在过去不同时间被烧毁的地点采集样本，这样我们就可以看到土壤C在火灾后1年，2年或长达20年之后是如何变化的。然后，这将用于开发最先进的陆地表面模型，JULES，这是英国地球系统模型的一部分。在我们的样本站点，我们将评估不同的燃烧严重程度如何影响土壤C，包括表层和深层土壤，以及这些如何随燃烧后的时间以及土壤、气候和土地利用（如伐木）而变化。在3个重点地点，我们将详细测量C在4年内的分解速率，并将测量结果与不同的土地利用、烧伤严重程度和干湿季节进行比较。了解火灾后C的形态以及它在不同条件下的分解速度，将使我们能够将这些过程构建到JULES模型中。我们将首次在全球范围内建立PyC模型，并对未来40-60年亚马逊地区在不同管理措施下的土地C变化进行预测。除了改变对火灾后土壤C及其对气候和管理的适应能力的科学认识外，我们的项目还将为可持续资源利用的社会环境规划提供信息，以保护土壤C。我们将与区域合作伙伴、火灾管理者、州和国家决策者合作，将我们的研究结果纳入决策，以最大限度地减少火灾的负面影响。由于我们的工作在亚马逊流域的规模，这些策略是限制大规模土壤流失风险的关键一步。

项目成果

From past to present : impacts of fire on Amazonian forests

从过去到现在：火灾对亚马逊森林的影响

• 发表时间: 2022
• 作者: Vedovato L.

Forest Fire History in Amazonia Inferred From Intensive Soil Charcoal Sampling and Radiocarbon Dating

• DOI: 10.3389/ffgc.2022.815438
• 发表时间: 2022-05
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: T. Feldpausch;L. Carvalho;K. Macario;P. Ascough;César F. Flores;E. H. Coronado;Michelle Kalamandeen;O. Phillips;R. Staff

A stoichiometric approach to estimate sources of mineral-associated soil organic matter

• DOI: 10.1111/gcb.17092
• 发表时间: 2024-01-01
• 期刊: GLOBAL CHANGE BIOLOGY
• 影响因子: 11.6
• 作者: Chang，Yi;Sokol，Noah W.;Ding，Fan
• 通讯作者: Ding，Fan

Ancient fires enhance Amazon forest drought resistance

古代火灾增强亚马逊森林的抗旱能力

• DOI: 10.3389/ffgc.2023.1024101
• 发表时间: 2023
• 期刊: Frontiers in Forests and Global Change
• 影响因子: 3.2
• 作者: Vedovato L

Effect of tree wood density on energy release and charcoal reflectance under constant heat exposure

恒定热暴露下树木密度对能量释放和木炭反射率的影响

• DOI: 10.1071/wf22156
• 发表时间: 2023
• 期刊: International Journal of Wildland Fire
• 影响因子: 3.1
• 作者: Crawford A