Comparing the estimated accuracy of destructive and non-destructive methods of aboveground carbon sequestration of velvet maple (Acer velutinum Boiss.) in Hyrcanian forests

Drought and environmental crisis caused by climate change are amongst the most crucial challenges in Iran. Due to the essential importance of absorbing CO2, the most crucial factor of global warming, in forest ecosystems, accurate estimation of carbon sequestration in different parts of the trees is of high significance for forest planning and management under climate change scenarios. In this study, 20 velvet maple (Acer velutinum Boiss.) individuals distributed in different diameter classes were initially felled and divided into separate parts of bole and crown. The specific wood density and carbon factor of each fraction and their product were directly calculated and used for non-destructive method to estimate above-ground carbon sequestration (AGC). Allometric equations were developed by weighing of harvested tree parts and measuring each section’s drought coefficient. The ANOVA revealed no tree-specific significant difference among carbon factors. However, the specific wood density was significantly different among the each part of tree individuals. Allometric models showed that the highest accuracy of AGC (R2adj = 0.98, RMS = 0.101, CF = 1.05) was achieved by the exponential model considered re-conversional equation that included DBH and crown diameter. The result of paired t-test showed that the non-destructive estimation method was associated with the highest uncertainty with the low confidence (S% = 318.4, t = -3.5). However, the result of paired t-test between the observations and predictions of the optimal allometric model here showed that the aforementioned model estimation was confident (S% = 22.6, t = 1.36).