Replanting and Yield Increase Strategies for Alleviating the Potential Decline in Palm Oil Production in Indonesia

CONTEXT: Maintaining stable and high levels of palm oil production within the current oil palm extent is a potential strategy to relieve deforestation pressure. Recent exponential growth of oil palm plantation area has led to significant carbon emissions and biodiversity loss. However, halting palm oil expansion may have adverse effects on palm oil production and the impact on the palm oil industry has not been well studied. OBJECTIVES: We developed quantitative methods to assess the potential decline of regional oil palm productivity given the landscape-level age-distribution structure on existing oil palm plantation land and evaluated strategies to alleviate this potential decline. These could provide guidance to multiple stakeholders, including mill owners, plantations, farmers, and regional governments, interested in improving and stabilizing palm oil yield. METHODS: We developed a model of palm oil production for Riau, Indonesia, where two decades of extensive industrial and smallholder oil palm expansion has occurred. Using established age-related rates of production, we investigated how palm oil productivity in current plantation areas would change over time if existing oil palm trees were cut and replanted at 25 years. We also designed scenarios based on replanting rates and yield improvements (better management practices or adopting more productive cultivars) to show the different im-pacts of replanting strategies. For each scenario, the production level was projected to 2075. RESULTS AND CONCLUSIONS: We found that the production of fresh fruit bunches from oil palm could fluctuate around 45 million metric tons if all current oil palm was replanted at 25 years with no further planted-area expansion. Replanting 4% annually, with or without yield improvements, would achieve the most stable landscape-level production. With yield improvements, the regional production could be increased to higher levels under any replanting rate. However, improving yields alone would be insufficient to prevent declining productivity trends in current plantation areas. Combining replanting with yield improvements could more quickly overcome potential declines in regional production. The age structure of oil palms in Riau is spatially heterogeneous across different districts, mills and concessions, posing increased challenges for replanting efforts to stabilize landscape-level yields. SIGNIFICANCE: Our study provides important information about the policy implications from different replanting and yield increase strategies on landscape-level palm oil production. Our findings demonstrate the need for collaborations among multiple stakeholders to maintain steady high levels of palm oil production in Riau, however varying stakeholder interests present major challenges for enabling and facilitating collaborations.