Abstract Maintaining forest conservation set-asides is a key criterion of sustainability certification of many crops that drive tropical deforestation, but their value for carbon storage and associated biodiversity is unclear. We conducted vegetation measurements to examine the benefits of set-asides for aboveground carbon stocks (AGC) in certified oil palm plantations on Borneo, and whether their AGC is positively associated with plant diversity. The mean estimated AGC of live trees and palms ≥10 cm diameter in set-asides in certified oil palm plantations (52.8 Mg ha−1) was >1.5-times that of oil palm (30.3 Mg ha−1), with some plots supporting similar AGC to primary forest. For lowland Borneo, we estimate that the average AGC of oil palm plantations with 10% coverage of set-asides is up to 20% greater than the average AGC of oil palm plantations without set-asides, newly demonstrating carbon storage as a benefit of conservation set-asides. We found positive relationships between AGC and plant diversity, highlighting the carbon–biodiversity co-benefits of set-asides. However, set-asides had a lower density of tree seedlings than continuous primary forest, indicating potential suppression of future tree regeneration and AGC. Our findings support the application of zero-deforestation during agricultural development, to conserve areas of remaining forest with high AGC and high biodiversity. We recommend management practices that boost regeneration in existing set-asides (e.g. enrichment planting), which would be most effective in larger set-asides, and could substantially increase the AGC of agricultural landscapes without removing land from production, and help conserve forest-dependent biodiversity.

中文翻译：

---

保护预留改善碳储存并支持经认证的可持续油棕种植园中相关的植物多样性

摘要 保持森林保护预留是许多导致热带森林砍伐的作物可持续性认证的关键标准，但它们对碳储存和相关生物多样性的价值尚不清楚。我们进行了植被测量，以检查婆罗洲认证油棕种植园为地上碳储量 (AGC) 预留的好处，以及它们的 AGC 是否与植物多样性呈正相关。经认证的油棕种植园 (52.8 Mg ha−1) 中直径 ≥ 10 cm 的活树和棕榈树的平均估计 AGC 是油棕 (30.3 Mg ha−1) 的 1.5 倍，一些地块支持类似于原始森林的 AGC。对于低地婆罗洲，我们估计，留出 10% 覆盖率的油棕种植园的平均 AGC 比没有留出的油棕种植园的平均 AGC 高 20%，这新近证明了碳储存作为保护留出的好处。我们发现 AGC 与植物多样性之间存在正相关关系，突出了预留的碳-生物多样性共同利益。然而，与连续的原始林相比，预留的树木幼苗密度较低，表明未来树木再生和 AGC 的潜在抑制。我们的研究结果支持在农业发展过程中应用零砍伐森林，以保护具有高 AGC 和高生物多样性的剩余森林区域。我们推荐促进现有预留地再生的管理实践（例如浓缩种植），