Habitat risk assessment of fragmented mangal ecosystem using InVEST models: a case study in San Fernando City, La Union, Philippines

La Union is renowned as one of the major tourist destinations in the Philippines, primarily the City of San Fernando, which houses a vast stretch of pristine coastal and wetland ecosystem that includes tropical beach and lush mangrove forests. However, despite the beneficial services mangal ecosystem provides for the coastal communities of San Fernando City, La Union, they remain vulnerable to risk caused by anthropogenic stressors in exchange for growing economic development. To ascertain this observation in the region, it is urgent that an evidence-based decision framework for the habitat risk of the remaining patches of the mangal ecosystem in smaller districts (barangays) of the whole municipality be established. Hence, this study was conceived by employing a mangal assessment based on exposure and consequence scores from anthropogenic stressors using the InVEST Habitat Risk Assessment model. Key findings showed the following: (1) the business-as-usual scenario configures a high cumulative risk due to road structures and other concrete pavements, (2) in a controlled and protected scenario, the mangal ecosystem will likely shift from medium to low risk, and (3) a reduction in cumulative risk for the mangal ecosystem is expected under public-private partnership intervention scenario. Nevertheless, the remaining sites in which the mangal ecosystem thrives must be targeted for intense active intervention and management from private and public stakeholders. This study serves as the basis for data-driven policies, highlighting the importance of adequately implementing management strategies to protect a critical wetland habitat.

Keywords:
Management strategies; Mangroves; Remote Sensing; Stressors; Vulnerability