Tree mortality is increasing world-wide, leading to changes in forest composition and altering global biodiversity. Nonetheless, owing to the multifaceted stochastic nature of tree mortality, large-scale spatial patterns of mortality across species ranges and their underlying drivers remain difficult to understand. Our main goal was to describe the geographical patterns and drivers of the occurrence of mortality (presence of a mortality event) and the intensity of tree mortality (amount of mortality related to that mortality event) in Europe. We hypothesized that the occurrence of mortality represents background mortality and is higher in the margin than in core populations, whereas the intensity of mortality could have a more even distribution according to the spatial and temporal stochasticity of die-off events.

中文翻译：

---

欧洲森林中树种范围的气候后缘上升，但死亡率并未上升

世界范围内的树木死亡率正在增加，导致森林组成发生变化并改变全球生物多样性。尽管如此，由于树木死亡率的多方面随机性，跨物种范围的大规模死亡率空间模式及其潜在驱动因素仍然难以理解。我们的主要目标是描述欧洲的地理模式和死亡发生的驱动因素（死亡事件的存在）和树木死亡的强度（与该死亡事件相关的死亡数量）。我们假设死亡率的发生代表背景死亡率，并且在边缘人群中高于核心人群，而根据死亡事件的空间和时间随机性，死亡率的强度可能具有更均匀的分布。