Fire versus water: ecosystem boundaries in tropical forest landscapes

火与水：热带森林景观中的生态系统边界

• 批准号: RGPIN-2019-05052
• 负责人: Schwartz, Naomi
• 金额: $ 2.04万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754824
• 关键词: Fire; versus; water; ecosystem; boundaries

Understanding the interactions between climate, disturbance, and vegetation and the ways human activities modify these relationships in tropical biomes is a major challenge with global implications. Over the next five years, my research program will identify key feedbacks between climate variability, soil properties, fire, and vegetation structure and function in seasonally dry tropical forests (SDTF). We will address the following short-term objectives: 1) Quantify the influence of climate variability and land use on fire regimes in SDTF landscapes and 2) identify key feedbacks between fire, soil conditions, and vegetation structure and function at boundaries between vegetation types. We will address these objectives with studies across multiple spatial scales, ranging from global analyses to individual leaves. Much of our work will take place in northern Cambodia, where deciduous dipterocarp forests, which resemble savanna and frequently burn, form patchy landscape mosaics and abrupt boundaries with dry evergreen forests. We will use this system as a model to understand anthropogenic and biophysical drivers of fire activity, feedbacks between fire, soil characteristics, and vegetation, and to explore relationships between plant species water-use strategies and fire sensitivity. To address Objective 1, we will use remote sensing to characterize fire regimes across all SDTF, and regionally within northern Cambodia, to explore factors that shape SDTF fire regimes. To address Objective 2, we will conduct field research to characterize variation in environment, forest structure and dynamics, and plant strategies across forest types. Measurements of functional traits related to water-use strategies and vulnerability to fire, along with data on soil characteristics and fire history will allow us to infer which environmental factors exert the strongest filters and to what degree fire favors particular water-use strategies. We will also use LiDAR to characterize forest structure, and link variation in forest structure to fire history at the landscape scale. Changes in tropical forest structure and function have large implications for carbon storage and biodiversity, but are difficult to predict, in part due to incomplete understanding of the processes that govern the boundaries between ecosystems. Global studies of forest-savanna boundaries have excluded southeast Asian ecosystems, limiting generality. By quantifying feedbacks between climate, fire, and vegetation in southeast Asian ecosystems, my research program will help resolve some of this uncertainty. Our research will have important applications for conservation and forest management, and our engagement with Cambodia's Forest Administration will ensure that our work directly affects local policy and management guidelines. The proposed research will train at least 8 HQPs, including 3 PhDs, 2 MScs, and 3 undergraduates, and will result in at least 10 peer reviewed publications.

了解气候、干扰和植被之间的相互作用以及人类活动改变热带生物群落中这些关系的方式是具有全球影响的重大挑战。在接下来的五年中，我的研究计划将确定气候变化、土壤特性、火灾以及季节性干燥热带森林 (SDTF) 中的植被结构和功能之间的关键反馈。我们将实现以下短期目标：1）量化气候变化和土地利用对 SDTF 景观火灾状况的影响，2）确定火灾、土壤条件以及植被类型边界处的植被结构和功能之间的关键反馈。 我们将通过跨多个空间尺度的研究来实现这些目标，从全局分析到单个叶子。我们的大部分工作将在柬埔寨北部进行，那里的落叶龙脑香科森林类似于稀树草原，经常燃烧，形成斑驳的景观马赛克，并与干燥的常绿森林形成鲜明的边界。我们将使用该系统作为模型来了解火灾活动的人为和生物物理驱动因素、火灾、土壤特征和植被之间的反馈，并探索植物物种用水策略和火灾敏感性之间的关系。 为了实现目标 1，我们将使用遥感技术来描述整个 SDTF 以及柬埔寨北部地区的火灾状况，以探索影响 SDTF 火灾状况的因素。为了实现目标 2，我们将进行实地研究，以表征环境、森林结构和动态以及不同森林类型的植物策略的变化。对与用水策略和火灾脆弱性相关的功能特征的测量，以及土壤特征和火灾历史的数据，将使我们能够推断哪些环境因素发挥最强的过滤作用，以及火灾在多大程度上有利于特定的用水策略。我们还将使用激光雷达来表征森林结构，并将森林结构的变化与景观尺度的火灾历史联系起来。热带森林结构和功能的变化对碳储存和生物多样性具有重大影响，但难以预测，部分原因是对控制生态系统之间边界的过程不完全了解。关于森林与稀树草原边界的全球研究排除了东南亚生态系统，限制了普遍性。通过量化东南亚生态系统中气候、火灾和植被之间的反馈，我的研究项目将有助于解决一些不确定性。我们的研究将对保护和森林管理有重要的应用，我们与柬埔寨森林管理局的合作将确保我们的工作直接影响当地的政策和管理准则。拟议的研究将培训至少 8 名 HQP，其中包括 3 名博士、2 名硕士和 3 名本科生，并将产生至少 10 篇同行评审出版物。