Abstract

Research on wood phenology has mainly focused on reactivation of the cambium in spring. In this study we investigated if summer drought advances cessation of wood formation and if it has any influence on wood structure in late successional forest trees of the temperate zone. The end of xylogenesis was monitored between August and November in stands of European beech and pedunculate oak in Belgium for two consecutive years, 2017 and 2018, with the latter year having experienced an exceptional summer drought. Wood formation in oak was affected by the drought, with oak trees ceasing cambial activity and wood maturation about 3 weeks earlier in 2018 compared with 2017. Beech ceased wood formation before oak, but its wood phenology did not differ between years. Furthermore, between the 2 years, no significant difference was found in ring width, percentage of mature fibers in the late season, vessel size and density. In 2018, beech did show thinner fiber walls, whereas oak showed thicker walls. In this paper, we showed that summer drought can have an important impact on late season wood phenology xylem development. This will help to better understand forest ecosystems and improve forest models.

中文翻译：

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干旱对晚演替落叶树种木材形成的秋季动态产生了截然不同的反应

摘要

木材物候学的研究主要集中在春季形成层的再活化。在这项研究中，我们调查了夏季干旱是否会促进木材形成的停止，以及它是否对温带晚期演替林木的木材结构有任何影响。2017 年和 2018 年连续两年（2017 年和 2018 年）在比利时的欧洲山毛榉和有花序橡树的林分中于 8 月至 11 月期间监测了木质形成的结束，后者经历了异常的夏季干旱。橡木的木材形成受到干旱的影响，与 2017 年相比，2018 年橡树停止形成层活动和木材成熟约提前 3 周。山毛榉在橡树之前停止木材形成，但其木材物候在年份之间没有差异。此外，在 2 年之间，环宽没有发现显着差异，晚季成熟纤维的百分比、血管大小和密度。2018 年，山毛榉的纤维壁较薄，而橡木的壁较厚。在本文中，我们表明夏季干旱会对晚季木材物候木质部发育产生重要影响。这将有助于更好地了解森林生态系统并改进森林模型。