Restoring tropical landscapes with resilient forests in the context of climate change mitigation

面对气候变化，热带森林至关重要。它们拥有40%以上的陆地碳，占据12%的陆地表面，拥有一半以上的陆地多样性。虽然避免砍伐森林是减少全球温室气体排放的一种方式，但重新造林和森林恢复提供了从大气中消除二氧化碳的机会。据估计，到2030年，气候缓解潜力为11PgCO2e yr-1，热带景观处于气候行动的前沿。在此背景下，我的NSERC探索基金重点关注热带森林对气候变化的适应能力。有人提出，与气候有关的气温和干旱增加可能会在全球范围内将热带森林从碳汇转变为碳源。森林作为气候解决方案的潜力取决于它们的长期复原力和承受气候变化和其他人为退化驱动因素的长期影响的能力。因此，我建议结合对实验林的研究，建立实验林是为了研究树木多样性和生态系统功能之间的关系，以及森林景观中气候适应能力的属性。2001年，我在巴拿马中部种植了一片实验林，有单一栽培的地块和混合地块。自那以后，它经历了一次极端潮湿事件，一次连续三年的极端潮湿干燥时段和一次热带风暴。对树木生长和其他生态系统功能的长期监测，如树叶凋落物和粗木质碎屑的产生，为揭示使混合地块对极端气候事件更具弹性的机制提供了独特的机会。此外，我将通过测量一些与潮湿和热带旱地种植森林的冠层树和树苗的抗旱性有关的功能特征，来促进对气候适应性的理解。正在测试的假设是，随着气候变得更加干燥，具有与抗旱有关的特征的树苗将大量增加，从而增强森林的复原力。我还将研究景观连通性作为景观弹性的关键要素，比较完整和破碎景观中树苗和树冠的多样性和功能特征。在全世界都在关注亚马逊森林的命运之际，我的研究将增进我们对热带森林气候适应能力的理解。此外，在德国的领导下，一些国家加入了波恩挑战，这是一项全球努力，目的是到2020年恢复1.5亿公顷被砍伐和退化的土地，到2030年恢复3.5亿公顷。我的探索赠款研究提供了如何提高重新造林和森林恢复项目的气候适应能力的指导，从而有可能对现实世界产生重大影响。

Tropical forests are critical in the face of climate change. They hold over 40% of terrestrial carbon, occupy 12% of terrestrial surface and harbour more than half of terrestrial diversity. While avoiding deforestation is one way to reduce global greenhouse gas emissions, reforestation and forest restoration offer an opportunity to remove CO2 from the atmosphere. With a climate mitigation potential estimated at >11 PgCO2e yr-1 up until 2030, tropical landscapes are at the forefront of climate action. In this context, my NSERC Discovery Grant focuses on tropical forests' resilience to the changing climate. It has been suggested that climate-related increases in temperature and drought could globally shift tropical forests from a carbon sink to source. The potential of forests to serve as climate solutions rests on their long-term resilience and ability to withstand chronic effects of climate change and other anthropogenic drivers of degradation. I therefore propose to combine research on an experimental forest, established to study the relationship between tree diversity and ecosystem function, and on the attributes of climate resilience in forested landscapes. In 2001, I planted an experimental forest in Central Panama with monoculture plots and mixture plots. Since then, it has experienced one extreme wet event, one extreme wet dry spell over three consecutive years and one tropical storm. Long-term monitoring of tree growth and other ecosystem functions, such as the production of leaf litter and of coarse woody debris, offers a unique opportunity to unravel the mechanism that makes mixture plots more resilient to extreme climate events. In addition, I will advance the understanding of climate resilience by measuring a number of functional traits related to drought resistance in canopy trees and saplings of both moist and tropical dry planted forests. The hypothesis being tested is that, as the climate is becoming drier, saplings harbouring traits related to drought tolerance will increase in abundance, thereby enhancing forest resilience. I will also examine landscape connectivity as a key element of landscape resilience, comparing saplings and canopy tree diversity and functional traits in intact and fragmented landscapes. My research will advance our understanding of the climate resilience of tropical forests at a time of worldwide concern over the fate of the Amazonian forests. Furthermore, under the leadership of Germany, a number of countries have joined the Bonn Challenge, a global effort to bring 150 million hectares of deforested and degraded land into restoration by 2020 and 350 million hectares by 2030. My Discovery Grant research holds the potential of having a major real-world impact by providing guidance on how to enhance the climate resilience of reforestation and forest restoration projects.