Detecting Vegetation Cover Change in Reforestation Sites from 2013 to 2019 in Central Visayas, Philippines Using Remotely Sensed Data

Abstract

Assessment of reforestation success is indispensable to document the impact of the project and whether it has achieved the intended objectives. Globally, the use of remotely sensed data is a widely accepted method to track changes in reforestation sites. Hence, this study investigated the changes in Normalized Difference in Vegetation Index (NDVI) using LandSat 8 images to assess vegetation cover in National Greening Program reforestation sites in Central Visayas from 2013 to 2019. Results showed that there was a minimal increase of NDVI (0.002 to 0.07) and a 9% (286 ha) gain of dense vegetation cover in the sampling sites which may be attributed to the reforestation activity. Forest gain was highest in Negros Oriental (262 ha) while Cebu lost 29 ha of dense vegetation. Field data confirmed that tree biomass density (245 Mg/ha) was highest in Negros Oriental and lowest in Cebu (78 Mg/ha). Analysis of variance revealed that there was no significant change in forest cover between 2013 and 2019. The program reported a total of 42,000 ha as their accomplishment in the region which was planted with 500 fast-growing tree species per hectare. If the seedlings successfully survived, this could have increased considerably forest cover in the region by up to 60%. Thus, it is important to revisit the reforestation program’s policies and processes to build on the strengths and avoid mistakes for future projects. It is also vital to integrate cost-effective, accurate, and real-time monitoring schemes that ensure the attainment of the key objectives.