Collaborative Research: Fire Influences on Forest Recovery and Associated Ecosystem Feedbacks in Arctic Larch Forests.

合作研究：火灾对北极落叶松森林恢复和相关生态系统反馈的影响。

基本信息

批准号：
1708129
负责人：
Jeremy Lichstein
金额：
$ 38.21万
依托单位：
University of Florida
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1708129&HistoricalAwards=false
关键词：
Collaborative Research Fire Influences Forest

项目摘要

Larch forests overlie extensive areas of Arctic permafrost and contain half the carbon (C) in some boreal forests. Although larch is a fire-dependent tree species, previous research and that of others suggests that increased fire activity may limit larch forest recovery and potentially trigger forest loss and a shift to alternative vegetation dominated by shrubs or grasses. Forest loss could have large consequences for climate because of changes in C storage and reflection of heat and light (albedo). Larch forests occur across much of the Arctic latitudinal treeline, and future larch recruitment dynamics will be a primary determinant of whether boreal forests respond to climate warming via treeline migration. Despite the global importance of these forests and the potential for an altered fire regime to modify recruitment patterns and future forest cover, larch forests remain largely understudied compared to the boreal forests of North America. The many mechanisms governing post-fire larch recruitment and the consequences for system-level feedbacks to regional and global climate remain untested. This research will link constraints on larch forest recruitment after fire to system-wide observations of larch recruitment failure and associated feedbacks to climate.&#8232;Boreal forests cover a large portion of the vegetated land area above the Arctic Circle and are a critical component of the Arctic System. In larch forests, increased fire activity associated with climate warming and drying can lead to larch recruitment failure, which in turn can limit forest recovery and trigger forest loss. A transition from forests to successional trajectories dominated by shrubs or grasses could have important consequences for climate feedbacks. The primary objective of this research is to delineate the causes of varying larch recruitment after fire and to quantify the consequences of larch recruitment failure for climate feedbacks via changes in C storage and albedo using a combination of field-based measurements, dendrochronological analysis, remotely-sensed data, and statistical modeling. The project hypothesizes that post-fire larch recruitment will be most constrained by seed sources (i.e., biological legacies) but that environmental conditions (e.g., soil organic layer depth) and biotic interactions (e.g., degree of mycorrhizal colonization and community structure) will impose secondary limitations on recruitment when seed sources are available. Larch recruitment failure will shift successional trajectories to those dominated by shrubs and grasses, resulting in reduced C storage, higher albedo, and cooling of regional climate. We will test hypotheses via field observations and experimental manipulations, combine field- derived data and statistical modeling to determine the factors that most influence larch recruitment, use high-resolution satellite imagery to determine the recent extent of regional larch recruitment failure after fire, and estimate C pools and albedo across gradients of larch recruitment and stand succession to determine the relative system-level consequences of changes in these parameters for regional climate forcing. By focusing on the mechanistic connections between fire and larch recruitment, the research will provide critical information on the net feedback of an intensified fire regime in arctic ecosystems to regional and global climate.&#8232;This project will train about 16 undergraduate students, one MS student, three PhD students, and two post-doctoral scholars. It will provide support for four female scientists, two of whom are early-career. It will share results with researchers in Amsterdam for inclusion in a circumpolar map of fire activity and forest recruitment, further improving international collaborations. Research findings will be widely disseminated to the scientific community through publications in scientific journals, presentations at national conference, and professional seminars. PIs will develop and lead a workshop aimed at improving middle school teachers' understanding of climate change science and their ability to effectively teach climate science to students.

落叶林森林覆盖了北极永久冻土的广泛地区，并在某些北方森林中含有一半的碳（C）。尽管落叶松是一种依赖火的树种，但先前的研究和其他研究表明，增加的火力活动可能会限制落叶林的恢复，并可能触发森林的丧失，并转向以灌木或草为主的替代植被。由于C储存和热量和光的反射（反照率），森林损失可能会对气候产生重大影响。大部分北极纬度林林发生了落叶林的森林，未来的落叶松招募动力学将是北方森林是否通过树木迁移对气候变暖做出反应的主要决定因素。尽管这些森林具有全球重要性，并且有可能改变火灾制度修改招募模式和未来森林覆盖的潜力，但与北美北美森林相比，落叶松森林在很大程度上得到了研究。关于射击后落期招募的许多机制以及对区域和全球气候的系统水平反馈的后果仍未经过测试。这项研究将将火灾森林招募后的限制与全系统范围的观察结果联系起来，对落叶池招募失败和相关的反馈与气候的观测。＆＃8232；北方森林覆盖了北极圆圈上方的植物土地区域的很大一部分，并且是北极系统的关键组成部分。在落期森林中，与气候变暖和干燥相关的火灾活动增加会导致落叶丘的募集失败，进而限制森林恢复并引发森林丧失。从森林到以灌木或草为主的森林过渡可能对气候反馈产生重要的影响。这项研究的主要目的是描述大火后改变落叶藻募集的原因，并通过使用基于现场的测量值，树突经理分析，遥远的数据和统计模型来量化落叶尔奇募集失败对气候反馈的后果。该项目假设射击后弓形招募将受到种子来源（即生物遗产）的最大约束，但是环境条件（例如，土壤有机层深度）和生物相互作用（例如，菌根菌落的殖民化和社区结构的程度）将对招募范围造成二次限制。梯级募集失败将使继任轨迹转移到以灌木和草为主导的轨迹上，从而导致C储存量减少，反照率更高和区域气候冷却。我们将通过现场观察和实验操作来检验假设，结合现场得出的数据和统计模型，以确定最大的因素影响拉更劳ch的招聘，使用高分辨率的卫星图像确定火灾后的区域larch招聘失败的最新程度强迫。通过关注火与劳ch招募之间的机械联系，该研究将提供有关北极生态系统中强化火灾制度对区域和全球气候的净反馈的关键信息。它将为四名女科学家提供支持，其中两名是早期职业。它将与阿姆斯特丹的研究人员共享结果，以包含在火灾活动和森林招募的近极地图中，从而进一步改善了国际合作。研究结果将通过科学期刊，全国会议和专业研讨会的出版物广泛传播给科学界。 PI将开发和领导一个旨在改善中学教师对气候变化科学的理解及其有效向学生教授气候科学的能力的研讨会。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Surface water, vegetation, and fire as drivers of the terrestrial Arctic-boreal albedo feedback

地表水、植被和火灾是陆地北极-北方反照率反馈的驱动因素

DOI：
10.1088/1748-9326/ac14ea
发表时间：
2021
期刊：
Environmental Research Letters
影响因子：
6.7
作者：
Webb, E E;Loranty, M M;Lichstein, J W
通讯作者：
Lichstein, J W

Evaluating Post-Fire Vegetation Recovery in Cajander Larch Forests in Northeastern Siberia Using UAV Derived Vegetation Indices

使用无人机导出的植被指数评估西伯利亚东北部卡尚德落叶松森林火灾后植被恢复情况

DOI：
10.3390/rs12182970
发表时间：
2020
期刊：
Remote Sensing
影响因子：
5
作者：
Talucci, Anna C.;Forbath, Elena;Kropp, Heather;Alexander, Heather D.;DeMarco, Jennie;Paulson, Alison K.;Zimov, Nikita S.;Zimov, Sergei;Loranty, Michael M.
通讯作者：
Loranty, Michael M.

Siberian Ecosystems as Drivers of Cryospheric Climate Feedbacks in the Terrestrial Arctic