NSFDEB-NERC: Gigante: Quantifying and upscaling the causes and drivers of death for giant tropical trees

这个名为Gigante的项目旨在了解热带森林中最大的树木死亡的时间、地点和原因。这项研究很重要，因为最大的1%的树木含有大量的碳：大约一半的碳储存在这些森林的植物中。然而，我们不知道是什么原因杀死了这些树，因此无法预测它们未来会怎么样，也不能预测它们对气候的影响。吉甘特将使用无人机指导野外团队定位和描述世界各地热带森林中数千棵巨型树木的死亡情况。然后，这些数据将被用来预测未来其他巨型树木可能死亡的时间和地点，并提高我们对当今地球上碳循环的理解。吉甘特的研究结果对于更好地理解热带森林对环境变化的脆弱性至关重要。该项目将通过一个国际网络培训新的和有抱负的科学家，利用现代技术研究巨型树木，生成所有巨型树木死亡的公开数据，以帮助卫星专家和其他人监测森林，并生成新的软件和培训材料，帮助科学家和土地管理人员监测世界范围内的森林健康。Gigante将使用多平台高频遥感技术，对五个超级站点的7500公顷热带森林进行定位，以确定巨型树木死亡事件的位置。这些数据将有助于使用详细的最先进的协议进行有针对性的现场调查，在史无前例的大规模现场研究中为最近死亡的树木分配最接近的致死因素。研究人员将把这些数据与有关气候、地形、树冠结构和树木特征的信息结合起来，以验证树木死亡风险的机制模型。最后，将这些风险模型与森林地块和卫星激光雷达相结合，他们将评估巨树死亡的驱动因素如何预测森林动态、结构和碳储存的空间差异。在这个项目的过程中，Gigante将制作软件和视频，以促进这些方法在其他地方的使用，并通过这个协作网络为科学家提供培训和能力建设。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project – named Gigante - aims to understand when, where, and why the largest trees in tropical forests die. The research is important because the largest 1% of trees contain enormous amounts of carbon: about half of all carbon stored in plants of these forests. However, we do not know what kills these trees and therefore can’t predict how they might fare in the future or their impact on climate. Gigante will use drones to guide field teams to locate and describe thousands of giant tree deaths in tropical forests around the world. These data will then be used to predict when and where other giant trees will likely die in the future and to improve our understanding of how carbon cycles on our planet today. Gigante’s outcomes are crucial to a better understanding of how vulnerable tropical forests are to environmental change. The project will train new and aspiring scientists across an international network in the use of modern technology for studying giant trees, generate publicly accessible data on all giant tree deaths to help satellite experts and others monitor forests, and generate new software and training materials to help scientists and land managers monitor the health of forests worldwide.Gigante will locate giant tree mortality events using multi-platform, high-frequency remote sensing of 7,500 hectares of tropical forest across five “super sites.” These data will facilitate targeted field surveys using detailed state-of-the art protocols to assign proximate agents of mortality to recently dead trees in an unprecedentedly large field study. The researchers will integrate these data with information about climate, topography, canopy structure, and tree traits to validate mechanistic models of tree mortality risk. Finally, combining these risk models with forest plots and satellite LiDAR, they will evaluate how drivers of giant tree death predict spatial variation in forest dynamics, structure, and carbon storage. In the course of this project, Gigante will produce software and videos to facilitate the use of these methods elsewhere, and provide training and capacity building to scientists across this collaborative network.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.