权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Immediate responses of forests to understorey fires during the 2010 Amazonian drought

2010 年亚马逊干旱期间森林对林下火灾的立即反应

基本信息

批准号：
NE/I018123/1
负责人：
Luiz Eduardo Aragão
金额：
$ 6.7万
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：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FI018123%2F1
关键词：
Immediate responses forests understorey fires

项目摘要

Despite an 82% decline in deforestation rates in Amazonia, fires are still on the rise. 2010 has been a year of severe drought and fire in Amazonia. Over the last months (July and August) the number of fire counts has reached 80% of the 2005 values, which was characterized as the drought of the century. Through the beginning of September, fire outbreaks have intensified in southwest Amazonia, including Brazil, Peru and Bolivia. This drought has been associated with warmer than average sea surface temperature in the tropical North Atlantic Ocean, in a scenario similar to the 2005 event. Amazon river levels near Iquitos and the Rio Negro near Manaus reached their lowest levels in the last 40 years and since the records began, respectively. This drought is perhaps the strongest ever recorded in this region. Droughts of this magnitude currently occur with a low frequency; however, their intensity and frequency are likely to increase in the 21st century, increasing the risk of severe wildfires in this fire-sensitive system. Understanding the impacts of forest fires on the carbon stocks and ecophysiology following the 2010 drought event is critical because these events may be common in the future climate of Amazonia. Moreover, we are still unable to predict the occurrence and extent of these droughts, we poorly understand how they affect forest fire patterns and how these fires impact the functioning of Amazonian forests. We therefore aim to quantify the impacts of drought-mediated fires on forest carbon stocks and functioning by investigating both the extent of the 2010 drought, and its influence on forest fires. In this project we will use this drought as a proxy for future climatic conditions in the region, which is likely to increase the probability of understorey forest fires. The Amazon is the largest tropical forest and most biodiverse ecosystem on the planet, storing around 86 billion tons of carbon in its biomass (currently similar to 10-years of fossil fuel emissions). Historically, fires in Amazonia have been reported to be rare, and it is unlikely that this biome is adapted to frequent fires. The increased trend in fire outbreaks in the last decades, associated to human activities, poses a growing risk to the stability of carbon stocks, functioning and diversity of Amazonian forests. Studying the effects of drought-induced fires on closed-canopy tropical forests can provide valuable insights regarding the responses of this ecosystem to future changes in the climate and environment. With our South American and American partners, this team is uniquely positioned to evaluate the effects of forest fires in Amazonia. This proposal brings together a multi-disciplinary group of local ecologists (which are currently tracking this drought on-the-ground), fire ecologists, climatologists as well as forest carbon and remote sensing experts in order to provide an integrative analysis of the climatology of this drought, the extent of forest fires and the carbon losses associated with this event. Working as a team, we will measure the different facets of this drought in multiple scales to provide a comprehensive assessment of its impacts. We will initially quantify the spatial extent of the drought and associated forest fires based on a combination of climate and remote sensing data. The team will then implement an extensive field survey to quantify the impacts of fires on carbon stocks and the functioning of the fire-affected forests. Finally, we will generate the first basin-wide map of the 2010 drought-induced fire impact on the Amazonian carbon stocks by integrating the previous data. Due to our close interaction with local governments and communities, we anticipate that this project will not only provide scientific information to help understand and diagnose the impacts of future events, but will also provide support for the development of public policies in order to mitigate climate change impacts in this region.

尽管亚马逊地区的森林砍伐率下降了82%，但火灾仍在增加。2010年是亚马逊地区严重干旱和火灾的一年。在过去的几个月里（7月和8月），火灾数量达到了2005年数值的80%，这被称为世纪干旱。9月初，亚马逊西南部，包括巴西、秘鲁和玻利维亚，火灾爆发加剧。这次干旱与热带北大西洋的海平面温度高于平均水平有关，其情景与2005年的事件类似。伊基托斯附近的亚马逊河水位和玛瑙斯附近的里约热内卢Negro水位分别达到了近40年来和有记录以来的最低水平。这次干旱可能是该地区有史以来最严重的一次。这种程度的干旱目前发生的频率较低；然而，在21世纪，它们的强度和频率可能会增加，这增加了这个火灾敏感系统发生严重野火的风险。了解2010年干旱事件后森林火灾对碳储量和生态生理的影响至关重要，因为这些事件可能在亚马逊地区未来的气候中很常见。此外，我们仍然无法预测这些干旱的发生和程度，我们对它们如何影响森林火灾模式以及这些火灾如何影响亚马逊森林的功能知之甚少。因此，我们的目标是通过调查2010年干旱的程度及其对森林火灾的影响，量化干旱介导的火灾对森林碳储量和功能的影响。在这个项目中，我们将使用干旱作为该地区未来气候条件的代表，这可能会增加下层森林火灾的可能性。亚马逊是地球上最大的热带森林和最具生物多样性的生态系统，其生物量储存了约860亿吨碳（目前相当于10年的化石燃料排放量）。从历史上看，亚马逊地区的火灾是罕见的，而且这种生物群落不太可能适应频繁的火灾。过去几十年来，与人类活动有关的火灾爆发趋势日益增加，对亚马逊森林的碳储量、功能和多样性的稳定性构成越来越大的风险。研究干旱引起的火灾对封闭冠层热带森林的影响，可以为该生态系统对未来气候和环境变化的反应提供有价值的见解。与我们的南美和美国合作伙伴一起，这个团队在评估亚马逊地区森林火灾的影响方面具有独特的优势。该提案汇集了一个由当地生态学家（目前正在实地跟踪这次干旱）、火灾生态学家、气候学家以及森林碳和遥感专家组成的多学科小组，以便对这次干旱的气气学、森林火灾的范围以及与此事件相关的碳损失提供综合分析。作为一个团队，我们将在多个尺度上测量这次干旱的不同方面，以提供对其影响的全面评估。我们将根据气候和遥感数据的结合，初步量化干旱和相关森林火灾的空间范围。然后，该小组将实施一项广泛的实地调查，以量化火灾对碳储量的影响以及受火灾影响的森林的功能。最后，通过整合之前的数据，我们将生成2010年干旱引发的火灾对亚马逊碳储量影响的首张全流域地图。由于我们与当地政府和社区的密切互动，我们预计该项目不仅将提供科学信息，帮助了解和诊断未来事件的影响，而且还将为制定公共政策提供支持，以减轻该地区气候变化的影响。