NI: Lightning in African tropical forests: from tree mortality to carbon dynamics

NI：非洲热带森林的闪电：从树木死亡率到碳动态

• 批准号: NE/W003872/1
• 负责人: Martin Sullivan
• 金额: $ 10.3万
• 依托单位: Manchester Metropolitan University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW003872%2F1
• 关键词: NI; Lightning; African; tropical; forests

Trees take in carbon from the atmosphere as they grow, but this is eventually released when they die. The sheer number of trees in tropical forests means that small changes in these rates of growth and death, and the resulting change in the balance of carbon taken in or released, can have a big effect on the climate. While a lot of research has focused on how changes in temperature and rainfall affects the growth and death of tropical forest trees, the potential effects of lightning have been largely neglected. A study tracking lightning strikes in Panama found that they caused more than half of all deaths of large trees, a previously undocumented effect despite being in one of the most intensively studied forests in the world. This project will provide important steps towards assessing whether this strong impact of lightning is a more widespread phenomenon. Forests in Africa are characterised by a greater dominance of large trees than elsewhere in the tropics, so based on results from Panama they would be expected to be more vulnerable to lightning. Alternatively, the high frequency of lightning in Africa may have selected for trees that are better able to withstand its effects. Knowing whether or not lightning has a consistent effect across continents is important for determining whether future work should focus on understanding the causes of variation in the impact of lightning, or can instead explore the wider implications these effects.The new international collaborator (Evan Gora) has developed an approach for detecting lightning damage from drone surveys and follow-up investigation on foot that allows large areas of forest to be surveyed. We will apply this at four sites along a dramatic gradient of lightning frequency in the Albertine Rift (on the boundary of the Democratic Republic of the Congo, Rwanda and Uganda) to (1) test whether trees at different sites in Africa are more or less vulnerable to being killed by lightning than those in Panama, (2) determine how forest structure varies with lightning frequency and (3) use these observations to assess the potential effect of lightning on carbon stocks and dynamics.The project team will have regular online meetings throughout the project, will all meet in Rwanda to receive training from Gora in how to detect lightning damage, and a subset of the team will also meet in the UK after fieldwork. Collectively, these meetings provide considerable space to share ideas as the project develops, culminating in a five-year plan for future collaboration. We will seek wider input from scientist and stakeholders through a regular series of seminars and roundtable discussions, and will hold online training workshops to build capacity in monitoring the effects of lightning on tropical forests.

树木在生长过程中从大气中吸收碳，但最终在死亡时释放。热带森林中树木的绝对数量意味着这些生长和死亡率的微小变化，以及由此导致的碳吸收或释放平衡的变化，都可能对气候产生重大影响。虽然许多研究都集中在温度和降雨量的变化如何影响热带森林树木的生长和死亡，但闪电的潜在影响在很大程度上被忽视了。一项跟踪巴拿马雷击的研究发现，它们造成了超过一半的大树死亡，尽管在世界上研究最深入的森林之一，但这种影响以前没有记录。该项目将为评估闪电的强烈影响是否是一种更普遍的现象提供重要步骤。非洲森林的特点是大树比热带其他地方更占主导地位，因此根据巴拿马的结果，预计它们更容易受到闪电的影响。另一种可能是，非洲闪电的频率很高，这可能选择了能够更好地承受闪电影响的树木。了解闪电在各大洲是否具有一致的影响对于确定未来的工作是否应该集中在了解闪电影响变化的原因上是很重要的，或者可以探索这些影响的更广泛含义。新的国际合作者（埃文戈拉）已经开发出一种方法，用于从无人机调查中检测闪电损害，并遵循-徒步调查允许大面积的森林被调查。我们将在艾伯丁裂谷的四个闪电频率梯度沿着地点应用这种方法（在刚果、卢旺达和乌干达的边界上）以（1）测试非洲不同地点的树木是否比巴拿马的树木更容易或更不容易被闪电杀死，（2）确定森林结构如何随闪电频率变化;（3）利用这些观测结果来评估闪电对碳储量和动态的潜在影响。项目团队将在整个项目的所有成员将在卢旺达会面，接受戈拉关于如何探测雷电损害的培训，团队的一部分成员也将在实地工作后在英国会面。总的来说，这些会议提供了相当大的空间来分享项目发展的想法，最终形成了未来合作的五年计划。我们将通过定期举办一系列研讨会和圆桌讨论会，广泛征求科学家和利益攸关方的意见，并将举办在线培训讲习班，以提高监测闪电对热带森林影响的能力。