Physiological response to rapid light exposure due to canopy disintegration in young beech, fir, Norway spruce and sycamore trees was measured in three consecutive years after the severe ice storm in 2014 and after windthrow in 2017. Nitrogen amount (N_tot), maximum assimilation response to light (A_max) and quantum yield (Φ) were measured in three categories of different light intensities under closed canopy with indirect site factor (ISF) < 15%, at the forest edge (15% <ISF < 25%) and in the open (ISF > 25%). Tree responses with number of seedlings per hectare were compared between damaged and undamaged sites, with young trees gradually adapting to light conditions in the two years following the two disturbance events.

Nitrogen levels were in the optimal range for all species studied. Rapid exposure to elevated light reduced efficiency in fir and increased efficiency in beech and especially sycamore. No differences in response were observed in spruce. Assimilation efficiency, where both tree species were equal, shifted towards shade. Recovery was similar for all species studied after both disturbances: better after the windstorm, compared to the ice storm, indicating the severity of the event. Reductions in seedling numbers followed the pattern observed for physiological traits.

在 2014 年严重冰暴后和 2017 年风吹后连续三年测量了年轻山毛榉、冷杉、挪威云杉和美国梧桐树冠层解体对快速光照的生理反应。 氮量 (N _tot )，最大同化反应在间接场地因子 (ISF) < 15% 的封闭冠层下、林缘 (15% < ISF < 25%) 和林缘下，在三类不同光强度下测量了光照 (A _max ) 和量子产率 (Φ)开放（ISF > 25%）。比较受损和未受损场地的每公顷幼苗数量的树木响应，在两次干扰事件发生后的两年内，幼树逐渐适应光照条件。

氮水平在所有研究物种的最佳范围内。快速暴露在强光下会降低冷杉的效率，提高山毛榉特别是美国梧桐的效率。在云杉中没有观察到响应差异。同化效率在两种树种相等的情况下转向遮荫。在两次干扰之后研究的所有物种的恢复情况相似：与冰暴相比，风暴过后更好，表明事件的严重性。幼苗数量的减少遵循生理特征观察到的模式。