Potential Impacts of INREMP on Selected Ecosystem Services in the KABAMAAM Watershed, Philippines

This study estimates changes in the values of selected ecosystem services (ES) in the KABAMAAM watershed of the Upper Chico River Basin, Cordillera Administrative Region, where the Integrated Natural Resources and Environmental Management Project (INREMP) implemented forest landscape restoration (FLR) interventions from 2013 to 2021. These included conservation farming, agroforestry, commercial tree plantations, assisted natural regeneration, and afforestation/reforestation. Soil erosion and sedimentation control and water yield were quantified using the InVEST model. At the same time, carbon sequestration was assessed through the Rapid Carbon Sequestration Assessment under “without” and “with INREMP” scenarios. Based on domestic and hydroelectric water use, the value transfer method was used to estimate ES values. Results showed that the KABAMAAM watershed’s capacity to provide ES improved under the “with INREMP” scenario. Carbon sequestration, erosion, sedimentation control, and water yield increased. Water provision for domestic use generated the highest value—ranging from US$10.5 million to US$15 million per year—while the total value of selected ES ranged from US$18.5 million to US$30.8 million annually. Given these values, replacing natural ES with man-made alternatives would be highly expensive. This study underscores the importance of sustained FLR interventions in enhancing ES that benefit multiple sectors. Thus, effectively managing the KABAMAAM watershed is essential to sustain and further improve its ecosystem service capacity.