Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy.
Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy.
Sci Total Environ. 2023 Jan 20;857(Pt 1):159239. doi: 10.1016/j.scitotenv.2022.159239. Epub 2022 Oct 6.
Extreme climate events such as late spring frosts (LSFs) negatively affect productivity and tree growth in temperate beech forests. However, detailed information on how these forests recover after such events are still missing. We investigated how LSFs affected forest cover and radial growth in European beech (Fagus sylvatica L.) populations located at different elevations at four sites in the Italian Apennines, where LSFs have been recorded. We combined tree-ring and remote-sensing data to analyse the sensitivity and recovery capacity of beech populations to LSFs. Using daily temperature records, we reconstructed LSF events and assessed legacy effects on growth. We also evaluated the role played by elevation and stand structure as modulators of LSFs impacts. Finally, using satellite images we computed Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and LAI (Leaf Area Index) to evaluate the post-LSF canopy recovery. The growth reduction in LSF-affected trees ranged from 36 % to 84 %. We detected a negative impact of LSF on growth only during the LSF year, with growth recovery occurring within 1-2 years after the event. LSF-affected stands featured low vegetation indices until late June, i.e. on average 75 days after the frost events. We did not find a clear relationship between beech forest elevation and occurrence of LSFs defoliations. Our results indicate a high recovery capacity of common beech and no legacy effects of LSFs.
极端气候事件，如晚春霜冻（LSFs），会对温带山毛榉林的生产力和树木生长产生负面影响。然而，关于这些森林在这些事件后如何恢复的详细信息仍然缺乏。我们调查了 LSFs 如何影响位于意大利亚平宁山脉四个地点不同海拔的欧洲山毛榉（Fagus sylvatica L.）种群的森林覆盖和径向生长，这些地点都有 LSFs 的记录。我们结合树木年轮和遥感数据来分析山毛榉种群对 LSFs 的敏感性和恢复能力。我们使用逐日温度记录来重建 LSF 事件，并评估其对生长的滞后效应。我们还评估了海拔和林分结构作为 LSFs 影响调节剂的作用。最后，我们使用卫星图像计算归一化差异植被指数（NDVI）、增强植被指数（EVI）和叶面积指数（LAI），以评估 LSF 后树冠的恢复情况。受 LSF 影响的树木的生长减少幅度从 36%到 84%不等。我们仅在 LSF 发生当年检测到 LSF 对生长的负面影响，并且在事件发生后 1-2 年内出现生长恢复。受 LSF 影响的林分的植被指数一直较低，直到 6 月底，即在霜冻事件后平均 75 天。我们没有发现山毛榉林海拔与 LSFs 落叶事件之间的明显关系。我们的研究结果表明，普通山毛榉具有较高的恢复能力，并且没有 LSFs 的滞后效应。
