Doctoral Dissertation Research: Spatial Resilience in Forests Recovering from Fires

该博士生将研究景观层面的过程如何支持严重烧毁的森林的再生和恢复力。具体来说，研究将集中在幸存的树木与景观相互作用的方式上，为烧毁地区的恢复提供外部种子来源。最近的研究只使用了有限的测量到最近的树种子源的直线距离，没有充分考虑规模、模式或与当地站点的相互作用，以恢复区域。因此，对于被烧毁地区的周围环境如何支持或减少其恢复潜力（空间弹性）的理解存在知识缺口。项目调查结果将有助于制定更好地解释世界上野火日益严重和频繁发生的景观背景的方法。考虑到这些变化，土地管理者必须决定哪些被烧毁的地区需要在野火活动后积极重新种植，哪些地区表现出更高的自然空间弹性。根据被烧毁地区在景观中的位置对其进行优先排序可能是这一决策的基础。为了协助决策，研究结果将作为决策树产品分发给当地和区域森林管理者。此外，该项目将为本科生提供教育机会，让他们参与实地考察，并举办讲习班，让K-12年级的女孩参与地理和空间科学。最后，该项目将支持一名女博士生，进一步扩大妇女和代表性不足群体在地理和空间科学领域的参与。确定景观背景对被烧毁森林恢复的重要空间尺度，是全面了解森林复原力和恢复的重要第一步。然而，尺度依赖效应往往是物种特异性的，因此确定相关的尺度必须考虑到不同的树木特征以及与当地树木生长适宜性的相互作用。为了做到这一点，博士生提出了三个研究问题：(1)什么样的空间范围和景观背景模式支持烧毁地区的恢复？(2)景观文脉如何与恢复区内场地特征相互作用？(3)在更广泛的时间和空间范围内，景观背景是否会调节干旱、易火景观中森林生态系统服务的恢复力？这些问题将通过统计建模和从大黄石生态系统的自然实验中产生的实地工作数据来回答。自然实验景观包括在相似的地球物理环境下代表燃烧模式梯度和火灾后气候条件的火灾，从而提供了一个独特的机会来观察景观背景对不同烧伤地区恢复的影响。此外，研究者将使用空间明确的生态系统过程模型来研究景观背景如何在更广泛的时空尺度上支持碳储存和树木生物多样性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The doctoral student will investigate how landscape-level processes support forest regeneration and resilience in forests that were severely burned. Specifically, the research will focus on the ways in which surviving trees interact with the landscape to provide external seed sources for a burned area's recovery. Recent studies used only a limited measurement of straight-line distance to nearest tree seed source, which does not fully consider scale, pattern, or interactions with local site suitability for area recovery. Consequently, there is a knowledge gap regarding an understanding of how a burned area's surrounding context in the landscape supports or reduces its recovery potential (spatial resilience). Project findings will contribute to the development of approaches that better account for landscape context in a world where wildfires are becoming more severe and occurring more frequently. Given these changes, land managers must make decisions about which burned areas need to be actively replanted following wildfire activity versus areas that exhibit higher natural spatial resilience. Prioritizing burned areas in the context of their position in the landscape could be fundamental to this decision-making. To aid with decision-making, research findings will be disseminated as a decision-tree product to local and regional forest managers. Furthermore, the project will provide educational opportunities for undergraduate students by involving them in fieldwork and by developing workshops that engage K-12 girls with geography and spatial sciences. Finally, the project will support a female doctoral student, further broadening participation of women and underrepresented groups in geography and spatial sciences.Identifying the spatial scales at which landscape context is important for a burned forest's recovery is an important first-step in a holistic understanding of forest resilience and recovery. However, scale-dependent effects are often species-specific, thus identifying relevant scales must account for divergent tree traits and interactions with local site suitability for tree growth. To do so, the doctoral student asks three research questions: (1) What spatial extents and patterns of landscape context support a burned area's recovery? (2) How does landscape context interact with local site characteristics of recovering areas? (3) At broader temporal and spatial extents, will landscape context mediate resilience of forest ecosystem services in drier, more fire prone landscapes? These questions will be answered using statistical modeling and fieldwork-generated data from a natural experiment in the Greater Yellowstone Ecosystem. The natural experimental landscape includes fires that represent a gradient of burn patterns and post-fire climate conditions in a similar geophysical setting, thereby providing a unique opportunity to observe the effects of landscape context on different burned areas' recovery. Additionally, the investigator will use a spatially explicit ecosystem process model to investigate how landscape context at broader temporal and spatial scales support carbon storage and tree biodiversity.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.