寒温带森林火后恢复轨迹及其对气候因子的响应OA

[Objective]Accurate assessment of post-fire vegetation recovery trajectories and their driving mechanisms is crucial for understanding forest ecosystem resilience.In particular,how burn severity modulates the sensitivity of recovery processes to climate change is especially critical.[Methods]Based on the Google Earth Engine(GEE)platform,Landsat time-series data from 2006 to 2024 and the LandTrendr algorithm were used to systematically analyze the 18-year vegetation recovery process following the 2006 megafire in the Gala Mountain Forest Farm,Heilongjiang Province.[Results]1)The overall post-fire vegetation recovery exhibited a"fluctuating upward"trend,with the normalized burn ratio(NBR)increasing by 0.01 per year on average.The pre-fire NBR level was exceeded in approximately 10 years,demonstrating strong ecosystem resilience.All burned areas recovered to 80％of the pre-fire level in the first year after the fire(Y2R80=1),reflecting an extremely fast initial recovery rate.2)Burn severity significantly shaped the recovery trajectories.Although high-severity burned areas suffered the most severe initial damage(ARI=-68％),they exhibited the fastest long-term recovery rate,suggesting a recovery pattern potentially reliant on pioneer species regeneration.In contrast,the recovery processes in low-and moderate-severity burned areas were more stable.3)Multiple linear regression models confirmed that land surface temperature(LST)significantly inhibited recovery(p＜0.01),whereas precipitation(Pr)significantly promoted recovery(p＜0.01).Critically,the intensity of climatic factor impacts was significantly modulated by burn severity.The model's explanatory power for high-severity burned areas(R2=34.91％)was much higher than that for low-severity burned areas(R2=26.77％),and the negative effect of LST was strongest in high-severity burned areas.[Conclusion]The findings reveal that severely damaged ecosystems are more sensitive to climate change,particularly to high-temperature stress.This study provides a key scientific basis for differentiated and climate-adaptive ecological management of post-fire cold-temperate forests.