Dead wood volume-to-carbon conversion factors by decay class for ten tree species in Croatia and eight tree genera globally

• Published in: Forest ecology and management 2023-12, Vol.549, p.121431, Article 121431
• Main Authors: Bitunjac, Doroteja, Ostrogović Sever, Maša Zorana, Sever, Krunoslav, Merganičová, Katarína, Marjanović, Hrvoje
• Format: Article
• Language: English
• Subjects: Carbon share loss; Dead wood basic density; Dead wood carbon fraction; Literature survey; Meta-mean; Relative density reduction patterns
• ISSN: 0378-1127
• DOI: 10.1016/j.foreco.2023.121431

•Species-specific dead wood basic density (DWBD) means by decay class are provided.•Decay class-specific conversion factors yielded 11.1%–26.6% lower estimate in national dead wood C pool.•Majority of studied tree species followed a steady decline pattern of relative wood density.•Genus-specific DWBD meta-means by decay class are available for use in the lack of local DWBD data. Dead wood (DW) is an important forest carbon (C) pool for which the reporting of C stock changes within the National Greenhouse Gas Inventory Report (NIR) is mandatory. The use of DW volume-to-carbon conversion factors by decay classes, i.e. DW basic density (DWBD) and C fraction (CF), or C density (CD) as their product, facilitates more accurate estimates of DW C stocks and C stock changes. We present DW conversion factors, namely DWBD, CF, and CD, by decay classes for six broadleaf (Quercus robur L., Carpinus betulus L., Alnus glutinosa Garnet., Fraxinus angustifolia Vahl., Fagus sylvatica L., and Quercus ilex L.) and four conifer (Abies alba Mill., Picea abies (L.) Karst., Pinus nigra Arnold and Pinus pinaster Aiton) tree species from Continental, Alpine and Mediterranean biogeographical regions of Croatia. For each tree species DW logs (diameter from 5 to 30 cm) were visually categorized into four decay classes and nine discs per decay class were sampled. In addition, three healthy trees of each species were felled down at the same location for estimating the basic density of fresh wood (BWD, decay class 0) and calculation of species-specific relative density reduction patterns. In total, 390 discs were sampled and analysed in the laboratory. Our results show that broadleaves, on average, have higher DWBD than conifers (p