Forests are generally known to have high carbon sequestration rates. Sustaining forest carbon sinks is a priority in climate change as well as forest management strategy. However, several issues confront the role of Philippine forests in climate change mitigation: the loss of old-growth cover, unsustainable forest land use practices, and lack of site-specific modeling. These are the realities in the Quirino Forest Landscape, a semi-contiguous collection of secondary forests in 4 municipalities of Quirino Province.

This study was undertaken to develop a forecast model for carbon in aboveground of underutilized trees in the Quirino Forest Landscape Project (QFLP) located in the Quirino Province. The study used forecasting variables such as DBH, abundance, density, and other related factors such as accumulation rate of AGB, change in forest cover, and time. Data were collected through field inventory, NAMRIA Land Cover Databases, and secondary sources. Multiple linear regression, principal components analysis, and biodiversity indices have been used in the analysis of data collected from different sampling areas and in the development of a forecast model. The results of the study showed the strong forecasting power of the developed model, which was precise enough to provide future values for the accumulated carbon in QFLP over the next 30 years. The 30-year forecast data showed that the average carbon sequestration in AGB of underutilized species of all forested areas in QFLP from 2020 to 2050 is QFLUSCarbon 228.88 G1C (SD-3.70). The high proportion of underutilized trees among those economically more important and more popular species of trees has also been observed in QFLP, indicating the dependence of its carbon sequestration on these species. The results of the analysis of forest cover change data illustrated the declining forest cover in the QFLP over the last several years, suggesting the need for policy-based management.

Thesis (Master of Science in Agricultural Engineering - Soil and Water Management)

Includes appendices and bibliographical references.