Lianas and ecosystem structure of secondary tropical dry forests

热带次生干旱林藤本植物和生态系统结构

• 批准号: RGPIN-2020-03888
• 负责人: SanchezAzofeifa, Gerardo
• 金额: $ 4.01万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739536
• 关键词: Lianas; ecosystem; structure; secondary; tropical

Seasonally dry tropical forests (TDFs) account for 42% of all tropical forests and contain a wealth of unique biodiversity. Plant species in this ecosystem have slower growth rates, restricted reproductive episodes, and more structural and physiological diversity than those found in tropical rainforests. In the Americas alone, it is estimated that nearly 60 million people benefit from the ecosystem services (e.g., water production, pollination) that TDFs provide. Despite their importance, little is known about their ecological response to climate change and how this response is reflected in their ecological succession processes (young vs. old forests). The objective of the proposed research program is to fill critical knowledge gaps in how TDFs respond to climate change and the consequent shifts in their ecosystem services. In the short-term, my research will focus on two main topics: (1) Determining the resilience mechanisms of tropical forests under climate change, especially in the context of the role that liana infestation plays on their functioning; and (2) Advancing our understanding of how TDFs respond to extreme climatic events using phenomena such as El Niño- Southern Oscillation (ENSO) as proxy for potential climate change scenarios. In the long-term, my research program aims to fill knowledge gaps integrating remote sensing, carbon flux measurements, ecosystem structure, and ecological processes at different stages of TDF regeneration. This information will assist policymakers in developing cost-effective and results-oriented methods for preserving this fragile ecosystem across the Americas. The short-term goals of my research program will involve four core areas of scientific discovery. These core areas aim to enhance the current understanding of: (1) the spatiotemporal variability of Essential Climatic Variables (ECVs) in liana-free and liana-infested regions; (2) the three-dimensional (structural) changes in TDFs induced by lianas; (3) the changes that liana loads induce in the metabolic conditions of the trees; and (4) the response of TDFs to extreme climatic events using eddy-covariance approaches. These questions will be studied at different spatial extents ranging from the individual plot to a regional scale. TDFs are among the least protected and studied ecosystems worldwide. Integrating research results from plot and landscape scales will further development of better mechanisms to monitor land cover changes and link those observations to conservation approaches. Also, by focusing on the impact that non-structural systems such as lianas have on TDFs, a better understanding will be gained of the response of this ecosystem to future climate change conditions.

季节性干燥热带森林（tdf）占所有热带森林的42%，包含丰富独特的生物多样性。与热带雨林相比，该生态系统中的植物物种生长速度较慢，繁殖期有限，结构和生理多样性更高。据估计，仅在美洲就有近6000万人受益于tdf提供的生态系统服务（例如，产水、授粉）。尽管它们很重要，但人们对它们对气候变化的生态响应以及这种响应如何反映在它们的生态演替过程中（年轻森林与老森林）知之甚少。拟议研究计划的目标是填补tdf如何应对气候变化及其生态系统服务随之变化的关键知识空白。在短期内，我的研究将集中在两个主要问题上：(1)确定气候变化下热带森林的恢复机制，特别是在藤本植物入侵对其功能的作用的背景下；(2)利用El Niño-南方涛动（ENSO）等现象作为潜在气候变化情景的代理，提高我们对tdf如何响应极端气候事件的理解。从长远来看，我的研究项目旨在填补遥感、碳通量测量、生态系统结构、TDF再生不同阶段生态过程等方面的知识空白。这些信息将有助于决策者制定具有成本效益和注重结果的方法，以保护整个美洲这一脆弱的生态系统。我的研究计划的短期目标将涉及科学发现的四个核心领域。这些核心区域旨在提高对以下方面的认识：(1)无藤本植物区和藤本植物区基本气候变量（ecv）的时空变异性；(2)藤本植物诱导tdf的三维（结构）变化；(3)藤本植物负荷对树木代谢条件的影响；(4)利用涡旋协方差方法分析tdf对极端气候事件的响应。这些问题将在不同的空间范围内进行研究，从单个地块到区域尺度。tdf是世界上保护和研究最少的生态系统之一。综合地块和景观尺度的研究结果将进一步发展更好的机制来监测土地覆盖变化，并将这些观察结果与保护方法联系起来。此外，通过关注诸如藤本植物等非结构系统对tdf的影响，将更好地了解该生态系统对未来气候变化条件的响应。