A clear-cutting of canopy trees during winter often causes severe foliar damage during the following spring in forest floor seedlings of Abies sachalinensis, a typical shade-tolerant evergreen coniferous species. The maximum photochemical efficiency of photosystem II after an overnight dark adaptation showed a temporary decrease immediately before budbreak in 1-year-old shoots of A. sachalinensis seedlings grown under full sunlight in a nursery, suggesting "springtime photoinhibition" related to the phenology of evergreen coniferous species. In the field, a greater rate of canopy tree cutting during winter was associated with more severe photoinhibition in the following spring, immediately before budbreak, which subsequently resulted in a reduction in carbon gain in 1-year-old shoots, and consequently suppressed the growth of current-year shoots. Although photoinhibition under low temperature is a well-known factor to determine the survival rate of tree seedlings during winter in cool regions, the present study additionally proposes that the temporary increase in the susceptibility to photoinhibition in springtime i.e. "springtime photoinhibition" would be a constraint for the regeneration of coniferous seedlings especially when the canopy trees are removed during winter.

中文翻译：

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春季光抑制限制了冬季移除树冠树木后大山冷杉林地幼苗的再生。


冬季对树冠树木的砍伐通常会在第二年春季对冷杉（一种典型的耐荫常绿针叶树种）的森林地面幼苗造成严重的叶子损害。在苗圃中全日照条件下生长的 1 年生大竹幼苗中，经过过夜暗适应后，光系统 II 的最大光化学效率在即将发芽前出现暂时下降，这表明与常绿植物物候相关的“春季光抑制”针叶树种。在田间，冬季树冠树木砍伐率较高，与第二年春天发芽前更严重的光​​抑制有关，这随后导致一岁芽的碳增益减少，从而抑制了生长今年的拍摄。尽管低温下的光抑制是决定寒冷地区冬季树苗成活率的众所周知的因素，但本研究还提出，春季对光抑制的敏感性的暂时增加，即“春季光抑制”将是一个限制因素用于针叶树苗的再生，特别是在冬季移除树冠树木时。