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

树木在生长过程中从大气中吸收碳，但最终在死亡时会释放出碳。热带森林中树木的绝对数量意味着，这些生长和死亡速度的微小变化，以及由此导致的碳吸收或释放平衡的变化，可能会对气候产生重大影响。虽然许多研究集中在温度和降雨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。一项追踪巴拿马雷击的研究发现，大树死亡的一半以上都是雷击造成的，尽管身处世界上研究最深入的森林之一，但这种影响之前并未记录在案。该项目将为评估闪电的这种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，与热带其他地区相比，大树的优势更大，因此根据巴拿马的结果，预计它们更容易受到闪电的影响。或者，非洲的高频率闪电可能选择了能够更好地抵御其影响的树木。了解闪电对各大洲的影响是否一致，对于确定未来的工作是应该专注于了解闪电影响差异的原因，还是可以探索这些影响的更广泛影响，具有重要意义。新的国际合作者(埃文·戈拉)已经开发出一种方法，可以通过无人机调查和后续徒步调查来检测雷击破坏，从而能够调查大片森林。我们将在阿尔伯丁裂谷(刚果民主共和国、卢旺达和乌干达的边界)闪电频率显著梯度的四个地点应用这一方法，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被雷击致死，(2)确定森林结构如何随着闪电频率的变化而变化，以及(3)使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期间定期召开在线会议，所有人都将在卢旺达接受GORA关于如何检测雷击破坏的培训。实地考察结束后，团队的一部分也将在英国会面。总体而言，随着项目的发展，这些会议提供了相当大的空间来交流想法，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，并将举办网上培训讲习班，建设监测闪电对热带森林影响的能力。

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.