Outbreaks of spruce bark beetle Ips typographus have devastating effects on European forest landscapes. Salvage removal of windfelled trees is deemed effective to prevent the outbreaks, although adverse effects on ecosystem recovery, ecologically valuable legacies, and unclear economic performance raise concerns about the widespread use of this practice. Here, we formulated a novel management framework aiming for the salvaging of a limited number of windfelled stands with the highest leverage for outbreak risk, potentially replacing the current large-scale uniform treatments. We demonstrated our concept in a Central European forest landscape using the forest disturbance model iLand and a newly developed optimization tool based on graph theory. We simulated the removal of 33% and 66% of windfelled trees in (i) stands randomly distributed on the landscape and (ii) stands identified by the optimization algorithm. Moreover, we tested the effect of (iii) a no-treatment strategy and (iv) complete removal of windfelled trees.

We found that the spatially optimized salvaging that aimed to remove 66% of the windfelled trees reduced the level of damage from bark beetles by 55%, whereas the non-optimized treatments, which removed the same volume of windfelled trees, reduced the damage by only 10%. In contrast to the reference treatments, the optimized approaches also retained their efficiency under elevated air temperature, which amplified the outbreaks. Although effects on deadwood retention were variable, the optimized treatments mitigated the economic impacts of the outbreak more effectively. The total loss of 7487 EUR ha⁻¹, incurred without any treatment, was reduced by 36.7%–68.9% (range for 33 % and 66 % salvaging intensity), whereas the loss reduction under the reference treatments was only 27.6%–57.7%.

We conclude that the spatially optimized salvaging proposed here can better balance multiple management objectives than the broadly applied uniform treatment, including the reduction of secondary disturbance from bark beetles, deadwood retention and economic goals.

云杉树皮甲虫Ips typographus的爆发对欧洲森林景观造成毁灭性影响。尽管对生态系统恢复，生态价值重大的遗留物以及不明确的经济表现产生了不利影响，但人们对这种风行树的打捞被认为可以有效地防止疫情的爆发，这引起人们对该做法的广泛使用的担忧。在这里，我们制定了一个新颖的管理框架，旨在挽救数量有限，风灾爆发风险最大的风摊林，有可能取代当前的大规模统一处理。我们使用森林干扰模型iLand和基于图论的最新开发的优化工具在中欧森林景观中展示了我们的概念。我们模拟了（i）在景观上随机分布的林分和（ii）通过优化算法确定的林分中33％和66％的风干树木的清除。此外，我们测试了（iii）无处理策略和（iv）完全清除风树的效果。

我们发现，旨在去除66％的风铃树的空间优化打捞将树皮甲虫的伤害水平降低了55％，而非优化的处理方法（去除了相同体积的风铃树）则仅减少了伤害。 10％。与参考治疗相反，优化的方法在空气温度升高的情况下也保持了效率，从而扩大了暴发。尽管对沉木保留的影响是可变的，但优化的处理方法可以更有效地减轻疫情的经济影响。未经任何处理而导致的总损失7487 EUR ha ^-1减少了36.7％–68.9％（挽救强度的范围为33％和66％），而参考处理下的损失减少仅为27.6％–57.7％ 。

我们得出的结论是，与广泛应用的统一处理方法相比，此处提出的空间优化打捞方法可以更好地平衡多个管理目标，包括减少树皮甲虫的继发性干扰，枯木保留和经济目标。