Deadwood represents a dynamic carbon pool in forest ecosystems where microbial decomposition causes fluxes of CO₂ to the atmosphere through respiration and organic carbon to the soil through leakage and fragmentation. This study characterises different stages of deadwood of Norway spruce (Picea abies). 35 Norway spruce trees were sampled and categorized on a 0–5 decay scale. For the 14 trees in classes 0–3, two stem discs were collected from two heights. For the 21 trees in classes 4 and 5, a single sample per tree was taken, because decay was relatively uniform throughout the stem. The relative amount of hemicellulose and cellulose declined moderately from decay class 1 to 3 and substantially from decay class 3 to class 4 but small amounts were still present in decay class 5. The relative lignin proportion increased substantially from decay class 3 to 4 and dominated in decay class 5. Relative carbon content increased from 50 to 56% during the decomposition process due to the increasing accumulation of lignin residuals being a typical signature of brown rot decay. A laboratory experiment including three species of brown rot fungi verified decomposition close to 70% of Norway spruce biomass and resulted in 55% carbon content. This was similar to the carbon content in decay class 4 and 5. A novel approach is presented to quantify the carbon flux from deadwood to the soil. First, we calculated the residual proportion of carbon in decayed wood compared to the initial carbon content of live trees. Subsequently, we extended the calculation to determine the amount of remaining carbon from non-decayed wood that was transferred to the soil during each decay class. The approach showed that Norway spruce wood decomposition under field conditions transfers at least 39–47% of the initial wood carbon to the soil carbon pool, depending on soil type. This strengthens the previously under-communicated fact that the carbon flux from deadwood to soil is higher from brown rot decomposition in boreal forests than the corresponding carbon flux in temperate and tropical forests where deadwood is more influenced by white rot fungi.

戴德伍德代表了森林生态系统中的动态碳库，其中微生物分解导致 CO ₂通过呼吸作用流入大气，有机碳通过泄漏和破碎流入土壤。本研究描述了挪威云杉（ Picea abies ）枯木不同阶段的特征。对 35 棵挪威云杉树进行了采样，并按照 0-5 级腐烂等级进行分类。对于 0-3 类的 14 棵树，从两个高度收集了两个茎盘。对于 4 类和 5 类的 21 棵树，每棵树只采集一个样本，因为整个树干的腐烂相对均匀。半纤维素和纤维素的相对量从腐烂等级 1 到 3 适度下降，从腐烂等级 3 到等级 4 大幅下降，但腐烂等级 5 中仍然存在少量。相对木质素比例从腐烂等级 3 到 4 大幅增加，并在腐烂等级 5 中占主导地位。腐烂等级 5。在分解过程中，由于木质素残留物的积累不断增加，相对碳含量从 50% 增加到 56%，这是褐腐病腐烂的典型特征。一项包含三种褐腐真菌的实验室实验证实，挪威云杉生物量已分解近 70%，碳含量达到 55%。这与腐烂等级 4 和 5 中的碳含量相似。提出了一种新方法来量化从枯木到土壤的碳通量。首先，我们计算了腐烂木材中碳的残留比例与活树的初始碳含量相比。随后，我们扩展了计算，以确定在每个腐烂等级期间未腐烂木材转移到土壤中的剩余碳量。 该方法表明，挪威云杉木材在野外条件下的分解将至少 39-47% 的初始木材碳转移到土壤碳库，具体取决于土壤类型。这强化了之前未充分传达的事实，即北方森林中褐腐分解导致的从枯木到土壤的碳通量高于温带和热带森林中相应的碳通量，而温带和热带森林中的枯木更容易受到白腐真菌的影响。