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

Abstract

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.