Changes in Carbon Stocks and the Economic Value of Forest Carbon in a Secondary Forest of Mt. Nacolod, Silago, Southern Leyte, Philippines

Tropical forests play a critical role in climate mitigation, yet long-term data on their carbon dynamics remain scarce, particularly in the Philippines. This study examines forest structure and carbon sequestration in a 1-hectare permanent plot established in a secondary forest on Mt. Nacolod, Southern Leyte, Philippines using 2012, 2016, and 2024 tree inventory data. The study aimed to (1) assess biomass and carbon storage trends, and (2) estimate the economic value of carbon. The secondary forest stored 202.4 Mg C/ha, comparable to reported values of old-growth forests in the Philippines. Its sequestration rate of 2.53 Mg C/ha/year is approximately nine times faster than old-growth forests and exceeds regional dipterocarp regrowth rates. Although sequestration slowed post-2016, the site remained a robust carbon sink. The estimated economic value of the stand’s carbon stock increased from USD 4,798 in 2012 to USD 7,220 in 2024, while carbon sequestered over the 12 years was valued at USD 1,076 under prevailing carbon credit prices. Key findings underscore the dominance of Dipterocarpaceae and the site’s high carbon sequestration capacity, emphasizing its critical role in regional climate mitigation strategies. Continuous monitoring reinforces its value as a long-term carbon sink, providing a benchmark for conservation and climate policy for tropical forests in the region.