The contribution of EU forests to climate change mitigation in 2021–2025 is assessed through the Forest Reference Levels (FRLs). The FRL is a projected country-level benchmark of net greenhouse gas emissions against which the future net emissions will be compared. The FRL models the hypothetical development of EU forest carbon sink if the historical management practices were continued, taking into account age dynamics. The Member States’ FRLs have been recently adopted by the European Commission with the delegated Regulation (EU) 2021/268 amending the Regulation (EU) 2018/841. Considering the complexity of interactions between forest growth, management and carbon fluxes, there is a need to understand uncertainties linked to the FRL determination. We assessed the methodologies behind the modelled FRLs and evaluated the foreseen impact of continuation of management practices and age dynamics on the near-future EU27 + UK forest carbon sink. Most of the countries implemented robust modelling approaches for simulating management practices and age dynamics within the FRL framework, but faced several challenges in ensuring consistency with historical estimates. We discuss that the projected 16% increase in harvest in 2021–2025 compared to 2000–2009, mostly attributed to age dynamics, is associated to a decline of 18% of forest sink (26% for living biomass only). We conclude that the FRL exercise was challenging but improved the modelling capacity and data availability at country scale. The present study contributes to increase the transparency of the implementation of forest-related EU policies and provides evidence-based support to future policy development.

中文翻译：

---

在欧盟设定森林参考水平：概述和挑战

欧盟森林对 2021-2025 年减缓气候变化的贡献通过森林参考水平 (FRL) 进行评估。FRL 是预计的国家级温室气体净排放基准，未来的净排放将与该基准进行比较。如果继续沿用历史管理实践，FRL 对欧盟森林碳汇的假设发展进行建模，同时考虑到年龄动态。欧盟委员会最近通过了成员国的 FRL，授权条例 (EU) 2021/268 修订了条例 (EU) 2018/841。考虑到森林生长、管理和碳通量之间相互作用的复杂性，有必要了解与 FRL 确定相关的不确定性。我们评估了建模 FRL 背后的方法，并评估了管理实践的延续和年龄动态对近期欧盟 27 国 + 英国森林碳汇的可预见影响。大多数国家实施了稳健的建模方法来模拟 FRL 框架内的管理实践和年龄动态，但在确保与历史估计的一致性方面面临一些挑战。我们讨论了与 2000-2009 年相比，2021-2025 年的预计收获量增加 16%，主要归因于年龄动态，这与森林汇减少 18%（仅活生物量减少 26%）有关。我们得出结论，FRL 活动具有挑战性，但提高了国家范围的建模能力和数据可用性。