Deadwood carbon pool and uncertainty estimates: effects of decay status and vegetation types

Deadwood carbon pool is a crucial component of forest ecosystems and the global carbon cycle. Assessing of deadwood carbon is challenging due to variability in decay status, species and disturbances in tropical forests. Quantifying the magnitude of uncertainty is essential for improving the accuracy of carbon stock estimations. This study aimed to estimate deadwood carbon pool by considering deadwood decay status and different vegetation types as well as the associated uncertainty in carbon stock estimates. Based on the National Forestry Resources Monitoring and Assessment of Tanzania (NAFORMA) sampling design, we analysed 21,946 data points from 1,798 plots. A two-way Analysis of Variance (ANOVA) was used to examine the variation in deadwood carbon stock (rotten and solid) between the primary vegetation types. Tukey’s Honest Significant Difference (HSD), post-hoc test was applied to determine which vegetation types significantly differ in carbon stock while a paired samples t -test was used to compare carbon stock of solid and rotten deadwood. Uncertainty was calculated using Equation 10 of 2006 IPCC Guidelines with 95% confidence interval. The estimated deadwood carbon stock ranged from 0.11 to 1.01 t C ha −1 , with solid deadwood having higher carbon stocks than rotten deadwood, accounting for 0.79% of total estimated carbon stocks. Carbon uncertainty values ranged from 0.0008 to 0.28%, with the highest and lowest uncertainty values from rotten deadwood in cultivated land and woodland, respectively. However, these variations among vegetation types did not significantly impact the deadwood carbon stock. In contrast, decay status had a significant effect on deadwood carbon stock. These findings are crucial for national climate policies, land use contributions to national carbon accounting, REDD+ mechanisms and sustainable management of natural ecosystems.