Technical University of Munich, TUM School of Life Sciences, Ecosystem Dynamics and Forest Management, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany; Berchtesgaden National Park, Doktorberg 6, 83471 Berchtesgaden, Germany.
Technical University of Munich, TUM School of Life Sciences, Earth Observation for Ecosystem Management, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany.
J Environ Manage. 2024 Aug;366:121659. doi: 10.1016/j.jenvman.2024.121659. Epub 2024 Jul 10.
Mountain forests play an essential role in protecting people and infrastructure from natural hazards. However, forests are currently experiencing an increasing rate of natural disturbances (including windthrows, bark beetle outbreaks and forest fires) that may jeopardize their capacity to provide this ecosystem service in the future. Here, we mapped the risk to forests' protective service across the European Alps by integrating the risk components of hazard (in this case, the probability of a disturbance occurring), exposure (the proportion of forests that protect people or infrastructure), and vulnerability (the probability that the forests lose their protective structure after a disturbance). We combined satellite-based data on forest disturbances from 1986 to 2020 with data on key forest structural characteristics (cover and height) from spaceborne lidar (GEDI), and used ensemble models to predict disturbance probabilities and post-disturbance forest structure based on topographic and climatic predictors. Wind and bark beetles are dominant natural disturbance agents in the Alps, with a mean annual probability of occurrence of 0.05%, while forest fires were less likely (mean annual probability <0.01%), except in the south-western Alps. After a disturbance, over 40% of forests maintained their protective structure, highlighting the important role of residual living or dead trees. Within 30 years after wind and bark beetle disturbance, 61% of forests were likely to either maintain or recover their protective structure. Vulnerability to fires was higher, with 51% of forest still lacking sufficient protective structure 30 years after fire. Fire vulnerability was especially pronounced at dry sites, which also had a high fire hazard. Combining hazard and vulnerability with the exposure of protective forests we identified 186 Alpine municipalities with a high risk to protective forests due to wind and bark beetles, and 117 with a high fire risk. Mapping the disturbance risk to ecosystem services can help identify priority areas for increasing preparedness and managing forests towards lower susceptibility under an intensifying disturbance regime.
山区森林在保护人民和基础设施免受自然灾害方面发挥着至关重要的作用。然而，森林目前正经历着越来越多的自然干扰（包括风倒、树皮甲虫爆发和森林火灾），这可能会危及它们未来提供这种生态系统服务的能力。在这里，我们通过整合危害（在这种情况下，干扰发生的概率）、暴露（保护人民或基础设施的森林比例）和脆弱性（干扰后森林失去保护结构的概率）的风险成分，绘制了整个阿尔卑斯山森林保护服务的风险图。我们将 1986 年至 2020 年的森林干扰卫星数据与基于星载激光雷达（GEDI）的关键森林结构特征（覆盖和高度）数据相结合，并使用集成模型基于地形和气候预测因子预测干扰概率和干扰后森林结构。风灾和树皮甲虫是阿尔卑斯山主要的自然干扰因素，年平均发生概率为 0.05%，而森林火灾的可能性较小（年平均概率<0.01%），除了阿尔卑斯山西南部。干扰后，超过 40%的森林保持了其保护结构，突出了剩余活树或死树的重要作用。在风灾和树皮甲虫干扰后的 30 年内，61%的森林可能会保持或恢复其保护结构。火灾的脆弱性更高，51%的森林在火灾发生 30 年后仍缺乏足够的保护结构。火灾脆弱性在干燥地区尤为明显，这些地区的火灾风险也很高。将危害和脆弱性与保护森林的暴露情况相结合，我们确定了 186 个阿尔卑斯山城镇，这些城镇因风灾和树皮甲虫而面临保护森林的高风险，117 个城镇面临高火灾风险。对生态系统服务的干扰风险进行测绘有助于确定优先地区，以增强防范意识，并在加剧的干扰机制下管理森林，降低其易感性。
