The production and fate of seaweed detritus is a major unknown in the global C-budget. Knowing the quantity of detritus produced, the form it takes (size) and its timing of delivery are key to understanding its role as a resource subsidy to secondary production and/or its potential contribution to C-sequestration. We quantified the production and release of detritus from 10 Laminaria hyperborea sites in northern Norway (69.6° N). Kelp biomass averaged 770 ± 100 g C m-2 while net production reached 499 ± 50 g C m-2 year-1, with most taking place in spring when new blades were formed. Production of biomass was balanced by a similar formation of detritus (478 ± 41 g C m-2 year-1), and both were unrelated to wave exposure when compared across sites. Distal blade erosion accounted for 23% of the total detritus production and was highest during autumn and winter, while dislodgment of whole individuals and/or whole blades corresponded to 24% of the detritus production. Detachment of old blades constituted the largest source of kelp detritus, accounting for > 50% of the total detrital production. Almost 80% of the detritus from L. hyperborea was thus in the form of whole plants or blades and > 60% of that was delivered as a large pulse within 1-2 months in spring. The discrete nature of the delivery suggests that the detritus cannot be retained and consumed locally and that some is exported to adjacent deep areas where it may subsidize secondary production or become buried into deep marine sediments as blue carbon.

中文翻译：

---

高纬度海带森林碎屑碳的产生和输出。


海藻碎屑的生产和去向是全球碳预算中的一个主要未知数。了解产生的碎屑的数量、其形式（大小）及其交付时间是理解其作为二次生产资源补贴的作用和/或其对碳封存的潜在贡献的关键。我们对挪威北部（北纬 69.6°）10 个海带地点的碎屑产生和释放进行了量化。海带生物量平均为 770 ± 100 g C m-2，而第一年净产量达到 499 ± 50 g C m-2，大部分发生在春季新叶片形成时。生物量的产生通过类似的碎屑形成来平衡（478 ± 41 g C m-2 年-1），并且在不同地点进行比较时，两者都与波浪暴露无关。远端叶片侵蚀占碎屑总产量的 23%，在秋季和冬季最高，而整个个体和/或整个叶片的移位相当于碎屑产量的 24%。老叶片脱落是海带碎屑的最大来源，占碎屑总量的50%以上。因此，来自 L. hyperborea 的碎屑几乎 80% 是整株植物或叶片的形式，其中超过 60% 在春季 1-2 个月内以大脉冲形式释放。交付的离散性质表明，碎屑不能在当地保留和消耗，一些碎屑被出口到邻近的深海区域，在那里它可能补贴二次生产或作为蓝碳埋入深层海洋沉积物中。