The impact of windthrow on carbon dynamics in temperate forests: a study case of Co. Laois in Ireland

Historic climatic data suggests that severe windstorms have been observed every 10-15 years in Ireland (Gallagher, 1974) and sometimes even more frequently, having a devastating impact on forests in the country. Such severe storms cause a significant number of trees to be uprooted or snapped (McInerney et al. 2016), a phenomenon commonly known as windthrow. Windthrow has extensive consequences for forest management, impacting the operations of forest for timber (wood volume shift to salvage wood, possible quality downgrade due to premature extraction, etc.), the dynamics of forests for nature (light availability, regeneration options, higher deadwood volume, etc.), the safety of forests for public use, the soil dynamics (especially for uprooted trees due to exposed soil), among others. In the context of climate change, natural disturbances such as windthrow might shift forests from carbon sinks to temporary carbon sources (Albrich et al. 2023). In order to understand the impact of windthrow on carbon dynamics in temperate forests, this work uses National Forest Inventory data from county Laois (Ireland) as a study case. Centrally located, county Laois has a forest cover (16.5%) higher than the national average (11.6%), and features diverse conditions, including varied soil types, forest types, as well as management purposes. This study models the impact of windthrow events on carbon pools in county Laois’ temperate forests using the CBM-CFS3 framework (Kurz et al. 2009). Varying disturbance intensities (25%, 50%, 70% and 100% of trees damaged by windthrow) are simulated, and their effects on carbon fluxes across biomass, soil organic carbon, and harvested wood products are analyzed. Management strategies, including salvage logging and natural regeneration, are evaluated to assess both immediate impacts and recovery potential, as well as their role in enhancing carbon resilience.