Aboveground dead wood has a range of important ecological functions, including carbon (C) storage. According to the Intergovernmental Panel on Climate Change guidelines for National Greenhouse Gas Inventories established on the basis of the United Nations Framework Convention on Climate Change and the Kyoto Protocol, Lithuania is encouraged to quantify C pools in forests, including C in living biomass, soil and dead wood. The aim of this study was to assess species-specific dead wood density (DWD) and carbon content (CC) per decay class for Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), silver birch or downy birch (Betula pendula Roth or Betula pubescens Ehrh.), European aspen (Populus tremula L.), grey alder (Alnus incana (L.) Moench), black alder (Alnus glutinosa (L.) Gaertn.), common oak (Quercus robur L.) and European ash (Fraxinus excelsior L.), as the main representative hemiboreal forest tree species. The study findings revealed that mean DWD significantly decreased, while mean CC slightly increased during the wood decomposition process, which led to carbon density (CD) reduction over five decay classes. The mean CC showed little variation among the eight tree species and ranged between 47 and 54%. The lower CDs in the dead wood of decay classes 1 and 2 were more associated with coniferous than deciduous species. The estimated CD significantly decreased in all species with increasing decay class. Dead wood at decay class 5 of Scots pine, silver or downy birch, European ash and common oak had the highest CD, followed by Norway spruce and grey alder, and the lowest CDs were obtained for European aspen and black alder.

中文翻译：

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立陶宛半北方森林主要树种死木碳密度

地上死木具有一系列重要的生态功能，包括碳 (C) 储存。根据基于《联合国气候变化框架公约》和《京都议定书》制定的政府间气候变化专门委员会国家温室气体清单指南，鼓励立陶宛量化森林中的碳库，包括活生物量、土壤和死木。本研究的目的是评估苏格兰松 (Pinus sylvestris L.)、挪威云杉 (Picea abies (L.) H. Karst.) 每个腐烂等级的物种特定死木密度 (DWD) 和碳含量 (CC)。 、银桦或绒毛桦 (Betula pendula Roth or Betula pubescens Ehrh.)、欧洲白杨 (Populus tremula L.)、灰桤木 (Alnus incana (L.) Moench)、黑桤木 (Alnus glutinosa (L.) Gaertn.) , 普通橡木 (Quercus robur L. ) 和欧洲白蜡 (Fraxinus excelsior L.) 为主要代表的半北方森林树种。研究结果表明，在木材分解过程中，平均 DWD 显着降低，而平均 CC 略有增加，这导致碳密度 (CD) 在五个腐烂等级中降低。八种树种之间的平均 CC 几乎没有变化，范围在 47% 和 54% 之间。腐烂等级 1 和 2 的枯木中较低的 CD 与针叶树种的关联度高于落叶树种。随着衰变等级的增加，所有物种的估计 CD 显着降低。腐朽等级为 5 的苏格兰松、银桦或绒毛桦、欧洲白蜡木和普通橡木的死木 CD 最高，其次是挪威云杉和灰桤木，欧洲白杨和黑桤木的 CD 最低。