With the increase in forest fire emissions, an increasing amount of nitrogen is released from combustibles and taken up by plant leaves in the form of PM2.5 smoke deposition. Concurrently, the stress from PM2.5 also disrupts the physiological processes of plants. This study aims to reveal the migration paths of N in combustibles in smoke and plants during forest fires and the stress response of plant leaves to smoke particle deposition. This study conducted a simulated smoke deposition treatment on Schima superba and Cunninghamia lanceolata, analyzing the changes in plant 15N content and stress-related products. The main findings include the following: (1) Nitrogen in combustibles can be transported to plant leaves via PM2.5 smoke during combustion and can be allocated and assimilated in various parts of the plant after being absorbed by the leaves. (2) The stress response of Schima superba to PM2.5 is less pronounced than that of Cunninghamia lanceolata. (3) Under PM2.5 stress, the correlation between nitrogen accumulation in the leaves of Schima superba and Cunninghamia lanceolata and their respective stress responses differs. In forest fires involving different tree species, there are variations in the migration pathways of nitrogen and the stress effects of PM2.5 on leaves, with a significant correlation observed between leaf nitrogen accumulation and stress response.

中文翻译：

---

PM2.5 烟雾暴露植物中的氮分配：对生态系统氮循环和胁迫响应的影响

随着森林火灾排放量的增加，越来越多的氮从可燃物中释放出来，并以PM2.5烟雾沉降的形式被植物叶子吸收。同时，PM2.5的胁迫也会扰乱植物的生理过程。本研究旨在揭示森林火灾期间烟雾和植物中可燃物中氮的迁移路径以及植物叶片对烟雾颗粒沉积的胁迫响应。本研究对木荷和杉木进行模拟烟雾沉降处理，分析植物15N含量及胁迫相关产物的变化。主要研究结果包括：（1）可燃物中的氮在燃烧过程中可通过PM2.5烟雾输送至植物叶片，被叶片吸收后可在植物各部位进行分配和同化。(2)木荷对PM2.5的胁迫反应不如杉木明显。(3)PM2.5胁迫下，木荷和杉木叶片氮素积累量与胁迫响应的相关性不同。在不同树种的森林火灾中，氮的迁移途径和PM2.5对叶片的胁迫影响存在差异，叶片氮积累与胁迫反应之间存在显着的相关性。