Community perceptions of long-term mangrove cover changes and its drivers from a typhoon-prone province in the Philippines

Background

This study was conducted in Eastern Samar, a typhoon-prone province in the Philippines, a country known for its vast mangrove forests. Mangrove forests are vital ecosystems that provide many benefits, including food, livelihoods, coastal protection, and carbon sequestration, also known as "blue carbon." However, these essential ecosystems are threatened globally, with human activities being the main cause of deforestation. Understanding long-term mangrove cover change (MCC) and its causes is essential for creating sustainable management strategies at local levels. Despite advancements in "blue carbon" research and MCC investigations using remote sensing in the Philippines, the drivers of these changes are often unclear, emphasizing the need for further research.

Goals and Methods

This research aimed to understand MCC dynamics in Eastern Samar, determine the proximate and underlying drivers of MCC at the local level, and show potential drivers of social perceptions of MCC. To achieve these goals, the researchers collected primary data through semi-structured household surveys in three coastal municipalities, targeting older residents to capture long-term perceptions. A total of 96 respondents shared their observations on mangrove changes, identified drivers, and ranked their importance. The researchers then supplemented and validated these community perceptions with secondary data, including historical satellite images from Google Earth, mangrove cover data from various sources, population density records, typhoon tracks, relevant environmental laws, information on mangrove planting activities, and data on respondents’ awareness of mangrove ecosystem services from a previous study. The researchers used descriptive statistics, weighted average using a ranking index, Spearman’s rank correlation, and multiple regression analyses to analyze the collected data. 

Conclusions and Takeaways

The study found that mangrove cover in Eastern Samar generally declined from the 1960s to 2016, but showed signs of recovery from 2016 to 2019. This finding aligned with community perceptions. Respondents perceived typhoons as the primary immediate cause of recent mangrove degradation. They also identified the lack of law enforcement as the most significant underlying cause of mangrove loss. Anthropogenic activities, such as the conversion of mangrove areas to residential spaces, drove significant mangrove loss in earlier periods. Successive reforestation programs and stricter implementation of local ordinances increased recent mangrove cover. This research highlights the value of community perceptions in recording mangrove cover change and identifying the drivers of these changes, especially when GIS-related approaches have limitations.