Dobor Laura, Hlásny Tomáš, Zimová Soňa
Faculty of Forestry and Wood Sciences Czech University of Life Sciences Prague Prague Czech Republic.
Ecol Evol. 2020 Oct 16;10(21):12233-12245. doi: 10.1002/ece3.6854. eCollection 2020 Nov.
Wind and bark beetle disturbances have increased in recent decades, affecting Europe's coniferous forests with particular severity. Management fostering forest diversity and resilience is deemed to effectively mitigate disturbance impacts, yet its efficiency and interaction with other disturbance management measures remain unclear.We focused on Central Europe, which has become one of the hotspots of recent disturbance changes. We used the iLand ecosystem model to understand the interplay between species composition of the forest, forest disturbance dynamics affected by climate change, and disturbance management. The tested measures included (a) active transformation of tree species composition toward site-matching species; (b) intensive removal of windfelled trees, which can support the buildup of bark beetle populations; and (c) reduction of mature and vulnerable trees on the landscape via modified harvesting regimes.We found that management systems aiming to sustain the dominance of Norway spruce in the forest are failing under climate change, and none of the measures applied could mitigate the disturbance impacts. Conversely, management systems fostering forest diversity substantially reduced the level of disturbance. Significant disturbance reduction has been achieved even without salvaging and rotation length reduction, which is beneficial for ecosystem recovery, carbon, and biodiversity. We conclude that climate change amplifies the contrast in vulnerability of monospecific and species-diverse forests to wind and bark beetle disturbance. Whereas forests dominated by Norway spruce are not likely to be sustained in Central Europe under climate change, different management strategies can be applied in species-diverse forests to reach the desired control over the disturbance dynamic. Our findings justify some unrealistic expectations about the options to control disturbance dynamics under climate change and highlight the importance of management that fosters forest diversity.
近几十年来，风灾和小蠹虫灾害有所增加，对欧洲的针叶林造成了尤为严重的影响。促进森林多样性和恢复力的管理措施被认为能有效减轻灾害影响，但其效率以及与其他灾害管理措施的相互作用仍不明确。我们聚焦于中欧地区，这里已成为近期灾害变化的热点地区之一。我们使用iLand生态系统模型来了解森林物种组成、受气候变化影响的森林灾害动态以及灾害管理之间的相互作用。测试的措施包括：（a）将树种组成积极转变为适合当地的物种；（b）大量清除被风刮倒的树木，这些树木可能会助长小蠹虫种群的增长；（c）通过调整采伐方式减少景观中成熟和易受灾树木的数量。我们发现，旨在维持挪威云杉在森林中主导地位的管理系统在气候变化下正逐渐失效，所采取的措施均无法减轻灾害影响。相反，促进森林多样性的管理系统大幅降低了灾害水平。即使不进行树木抢救和缩短轮伐期也实现了显著的灾害减少，这有利于生态系统恢复、碳储存和生物多样性。我们得出结论，气候变化加剧了单一树种森林和物种多样森林在遭受风灾和小蠹虫灾害时脆弱性的差异。在气候变化下中欧地区以挪威云杉为主的森林不太可能持续存在，而在物种多样的森林中可以采用不同的管理策略来实现对灾害动态的理想控制。我们的研究结果证明了对气候变化下控制灾害动态的选项抱有一些不切实际期望的不合理性，并强调了促进森林多样性管理的重要性。
