Assessing Amazon forest vulnerability and resilience to dry periods across soil moisture and microenvironmental gradients

评估亚马逊森林在土壤湿度和微环境梯度下的干旱期脆弱性和恢复能力

• 批准号: 2882399
• 金额: --
• 依托单位: Bangor University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2882399
• 关键词: Assessing; Amazon; forest; vulnerability; resilience

Climate-change-related droughts in the Amazon rainforest can cause widespread tree mortality, resulting in large carbon emissions, with potential feedbacks to regional and global climate (Phillips et al. 2009; Brienen et al. 2015). However, much of our knowledge of tropical forest drought responses comes from deep water table depth (WT) forests. Shallow WT forests are severely under-researched, despite occupying ~50% of the Amazon basin, and being expected to respond differently to drought (Costa, Schietti, Stark, Smith 2022). Recent results indicate that shallow WT areas benefit from moderate drying, which reduces anoxia and extends the growing season (Esteban et al. 2021, Sousa et al. 2022). As such, shallow WT forests may be more resilient to drought, potentially capable of offsetting large carbon losses anticipated from deep WT forests. To accurately project the future of this globally important ecosystem and set conservation priorities, we need to understand the contribution of shallow WT forests to Amazon forest carbon balance and how soil water availability influences tropical forest vulnerability or resilience to drought.We will investigate how soil water availability (using WT as a proxy) influences Amazon forest responses to seasonal dry periods (and if observed, droughts). Specifically, we will quantify seasonal patterns of key components of forest carbon-vertical leaf area distributions (from ground-based lidar) and tree woody growth (from dendrometers) -and test potential drivers, including soil moisture, microenvironmental conditions, and tree hydraulic strategy.

亚马逊雨林中与气候变化相关的干旱可能会导致广泛的树木死亡率，导致大量碳排放，并具有对区域和全球气候的潜在反馈（Phillips等，2009； Brienen等，2015）。但是，我们对热带森林干旱反应的许多了解都来自深水桌深度（WT）森林。尽管占据了约50％的亚马逊盆地，但浅水林的浅林被严重研究，并被期望对干旱做出不同的反应（Costa，Schietti，Stark，Stark，Smith 2022）。最近的结果表明，浅WT区域受益于中度干燥，从而减少了缺氧并延长生长季节（Esteban等，2021年，Sousa等，2022）。因此，浅wt森林可能对干旱更具弹性，可能能够抵消深WT森林预期的大量碳损失。为了准确地投影这一全球重要的生态系统的未来并设定了保护优先级，我们需要了解浅木林对亚马逊森林碳平衡的贡献以及土壤水的可用性影响热带森林的脆弱性或对干旱的韧性。我们将如何研究土壤水的可用性（使用wt作为Amazon Forest对季节性的反应，都会影响到季节性的季节性干燥时期（以及是否对季节性抗衡）（如果对季节性的干旱）进行了探测（以及）（如果对）进行了斗争（以及）（如果对）进行了干旱（以及）（如果均可对季节性的干燥时期进行探测。具体而言，我们将量化森林碳垂直叶面积分布的关键组成部分的季节性模式（来自地面的LIDAR）和树木木制的生长（来自树枝状计量仪）以及测试潜在驱动因素，包括土壤水分，微环境条件和树液压策略。