Post-fire vegetation succession in the Siberian subarctic tundra over 45 years

Wildfires are relatively rare in subarctic tundra ecosystems, but they can strongly change ecosystem properties. Short-term fire effects on subarctic tundra vegetation are well documented, but long-term vegetation recovery has been studied less. The frequency of tundra fires will increase with climate warming. Understanding the long-term effects of fire is necessary to predict future ecosystem changes. We used a space-for-time approach to assess vegetation recovery after fire over more than four decades. We studied soil and vegetation patterns on three large fire scars (>44, 28 and 12 years old) in dry, lichen-dominated forest tundra in Western Siberia. On 60 plots, we determined soil temperature and permafrost thaw depth, sampled vegetation and measured plant functional traits. We assessed trends in NDVI to support the field-based results on vegetation recovery.Soil temperature, permafrost thaw depth and total vegetation cover had recovered to pre-fire levels after >44 years, as ...

亚寒带苔原（subarctic tundra）生态系统中的野火事件相对罕见，但野火可显著改变该生态系统的属性。现有研究已充分记录了野火对亚寒带苔原植被的短期影响，但针对植被长期恢复的相关研究则相对较少。随着气候变暖，苔原野火的发生频率将呈上升趋势。明晰野火的长期影响，是预测未来生态系统变化的必要前提。本研究采用空间替代时间法（space-for-time approach），评估了四十余年尺度下野火后的植被恢复情况。我们以西伯利亚西部以地衣为主的干燥森林苔原中的三处大型火烧迹地（过火年限分别超44年、28年及12年）为研究对象，分析了其土壤与植被特征。在60个样地中，我们测定了土壤温度与永久冻土融化深度，采集了植被样本并测量了植物功能性状（plant functional traits）。我们通过归一化差异植被指数（Normalized Difference Vegetation Index，NDVI）的变化趋势，佐证了野外调查得到的植被恢复结果。在过火时长超44年的样地中，土壤温度、永久冻土融化深度与总植被覆盖度均已恢复至火灾前水平，……