A forest fire in a cool-temperate broadleaved forest in northern Japan, from 26 May to 19 June 2019, provided an opportunity to examine the post-fire dynamics of young, dense birch (Betula ermanii Cham.) stands that had previously undergone top soil removal through soil scarification. To characterize the post-fire responses (survival and resprouting) of birch trees, we set up two plots, 6 months after the fire. We investigated the trunk diameter at breast height and burn marks on the trunks (scorch height and bole charring percentage) of all B. ermanii trees in both plots. Survival and resprouting of each tree were monitored over a 10-month period (6 and 16 months after the fire). To quantify post-fire vegetation recovery of the forest floor, we manually mapped the dominant understory plant, dwarf bamboo (i.e. Sasa kurilensis (Rupr.) Makino et Shibata), from orthomosaic images obtained using an unmanned aircraft vehicle, and estimated the recovery rate in the second year after the fire. Additionally, the seedlings of woody species were counted in both plots. A logistic generalized linear model revealed that the size-dependent survival rates of the plants in each plots were similar in the first year after fire. All B. ermanii trees died without resprouting in the second year after the fire, indicating the lethal effects of fire on young birch trees in top soil removal sites. Moreover, a high recovery rate of dwarf bamboo over 2 years in both plots and limited woody seedling establishment of woody plants suggest that the fire resulted in the regeneration failure of young stands in the top soil removal sites. Based on these findings, we suggest that the vulnerability of young trees can lead to the rapid change in vegetation from young forest to dense dwarf bamboo cover after a fire.

中文翻译：

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在顶部土壤清除地点的野火后，年轻、密集的白桦的生存

2019 年 5 月 26 日至 6 月 19 日，日本北部一处冷温带阔叶林发生森林火灾，提供了一个机会来检查以前经历过表层土壤的年轻、密集的白桦 (Betula ermanii Cham.) 林分的火灾后动态通过土壤松土去除。为了描述白桦树的火灾后响应（生存和重新发芽），我们在火灾发生 6 个月后设置了两个图。我们调查了两个地块中所有 B. ermanii 树的胸部高度的树干直径和树干上的烧伤痕迹（焦化高度和树干炭化百分比）。在 10 个月内（​​火灾后 6 个月和 16 个月）监测每棵树的存活和重新发芽。为了量化森林地面的火灾后植被恢复，我们手动绘制了主要的林下植物矮竹（即 Sasa kurilensis (Rupr. ) Makino et Shibata)，来自使用无人驾驶飞行器获得的正射镶嵌图像，并估计火灾后第二年的恢复率。此外，在两个地块中都计算了木本植物的幼苗。逻辑广义线性模型显示，火灾后第一年，每个地块中植物的大小依赖性存活率相似。B. ermanii 所有的树木在火灾发生后的第二年都没有再发芽就死亡了，这表明火灾对顶部土壤清除地点的年轻白桦树造成了致命的影响。此外，两块地的矮竹在 2 年内的高恢复率和木本植物的木本幼苗建立有限表明火灾导致顶部土壤去除地点的幼林再生失败。基于这些发现，