Carbon Storage Potential of Integrated Forest Patches and Banana (Musa spp.) Agroecosystems in the Agricultural Landscape of Mindanao, Philippines

Agroecosystems are known to cause high depletion of terrestrial carbon stocks, and their expansion is seen to reduce natural habitats within agricultural landscapes to smaller patches. Understanding the carbon storage potential of these systems is essential for optimizing ecological benefits and addressing gaps in carbon accounting, which often overlook forest patches in agricultural areas. This study quantified the carbon storage potential of small forest patches and banana agroecosystems within agricultural landscapes in Mindanao, Philippines. Results indicated that forest patches had significantly higher biomass carbon (60.3 ± 12.2 to 206.4 ± 47.2 Mg ha⁻¹) than banana agroecosystems (22.78 to 85.21 Mg ha⁻¹). Carbon storage in forest patches was concentrated in trees (60–70%) and roots (15–20%), while in banana agroecosystems it was primarily in pseudo-stems (45–55%) and litter layer (45–50%). Soil organic carbon was comparable between forest patches (45.45–95.33 Mg ha⁻¹) and banana agroecosystems (47.96 to 80.53 Mg ha⁻¹). The absence of understorey vegetation in banana agroecosystems reflects the impact of intensive management practices. Despite this, banana agroecosystems had higher carbon accumulation rates (86.70 ± 24.92 Mg ha⁻¹ yr⁻¹) than forest patches (41.63 ± 16.31 Mg ha⁻¹ yr⁻¹) but lower CO₂ fixation (5.96 ± 1.48 vs . 8.89 ± 1.48 Mg CO₂-eq ha⁻¹ yr⁻¹). While the rapid growth rates of bananas drive their carbon accumulation, their short harvest cycles limit long-term storage, unlike the woody biomass in forest patches. These findings emphasize the need for agroforestry policies that promote integrated management of forest patches and agricultural lands for optimal carbon storage.