With the global warming, the frequent and severe river floods in Arctic regions have affected the distribution of willows in river lowlands. To investigate the effect of floods, especially waterlogging, on nitrogen conditions for willows, we measured their foliar nitrogen content and isotopic composition (δ¹⁵N), under various hydrological conditions in Northeastern Siberia, which was classified into four conditions according to the previous study: dry, wet, waterlogging [WL], long-period waterlogging [LWL] respects to willows’ physiological response. The δ¹⁵N values of willow leaves, which correlate to those of the soil, were significantly lower under dry (−3.6 ± 1.3‰) and wet (−3.5 ± 1.7‰) than WL (0.3 ± 2.6‰) and LWL (2.7 ± 2.4‰), indicates acceleration of soil nitrogen dynamics for waterlogging. There is no higher foliar nitrogen contents found under LWL (2.3 ± 0.3%) than WL (2.4 ± 0.4%). This might be caused by little decreased nitrogen uptake related to the low activity of carbon fixation in willows under LWL. Interestingly, LWL occurred over a wide area following extreme flooding in 2017; yet, willows survived, whereas potential competing species (larch) died. We further predict that the distribution of willows in Arctic riparian areas will expand, particularly after extreme floods under Arctic amplification.

随着全球变暖，北极地区频繁且严重的河流洪水影响了低河地区柳树的分布。为了研究洪水，特别是淹水，对柳树氮条件的影响，我们测量了它们的叶面氮含量和同位素组成（δ ¹⁵根据先前的研究N），东北西伯利亚，各种水文条件将其分为四个条件下：干燥，湿润，涝渍[WL]，长期涝渍[LWL]与柳树的生理反应有关。该δ ¹⁵在土壤干（-3.6±1.3‰）和湿（-3.5±1.7‰）下，柳叶的N值与土壤的N值显着低于WL（0.3±2.6‰）和LWL（2.7±2.4‰）。 ），表示用于涝渍的土壤氮动力学加速。LWL（2.3±0.3％）下没有发现高于WL（2.4±0.4％）的叶面氮含量。这可能是由于LWL下柳树的固碳活性低而导致氮吸收减少很少。有趣的是，在2017年发生特大洪水之后，LWL发生在广泛的地区; 然而，柳树得以幸存，而潜在的竞争物种（落叶松）死亡。我们进一步预测，北极沿岸地区的柳树分布将会扩大，尤其是在北极放大作用下发生的特大洪灾之后。