Knowing which restoration approach provides the best returns on investment for accumulating carbon is essential to foster restoration planning, financing, and implementation. Here, we explored the cost‐effectiveness and drivers of aboveground and soil carbon accumulation in restored forests across an agricultural landscape of Brazil's Atlantic Forest. The recovery of aboveground and soil carbon stocks, as well as the implementation and land opportunity costs, was assessed across chronosequences (10–60 years) of second‐growth forests and mixed‐species tree plantings and old growth, reference forest remnants. Plantations accumulated approximately 50% more aboveground carbon than second‐growth forests throughout the chronosequence. When controlling for soil clay content, soil carbon stocks were higher in reference than in restored forests, but they were comparable between plantations and second‐growth forests. After 60 years of stand development, recovery of total carbon stocks in both restoration approaches reached only half of the average stocks of reference forests. Total cost‐effectiveness for carbon accumulation, including both implementation and land opportunity costs, was on average 60% higher for second‐growth forests than for plantations (15.1 and 9.4 kgC US$⁻¹, respectively). Although tree plantations initially showed higher rates of carbon storage than second‐growth forests, their higher implementation and land opportunity costs make them less cost‐effective for carbon farming. Our results further suggest that, at current pricing levels, carbon markets alone have a limited potential to up‐scale restoration efforts in Brazil's Atlantic Forest.

中文翻译：

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恢复巴西大西洋森林碳库的成本

知道哪种恢复方法可以为碳积累提供最佳的投资回报，这对于促进恢复计划，融资和实施至关重要。在这里，我们探索了巴西大西洋森林农业景观中恢复森林中地上和土壤碳积累的成本效益和驱动因素。在第二次生长的森林和混合树种的种植以及老龄树种，参考林残余物的时间序列（10-60年）中评估了地上和土壤碳储量的恢复，以及实施和土地机会成本。在整个时间序列上，人工林累积的地上碳比第二生长林高出约50％。在控制土壤黏土含量时，参考土壤碳储量比恢复森林要高，但是它们在人工林和次生林之间具有可比性。林分经过60年的发展，两种恢复方式的总碳储量仅达到参考林平均储量的一半。次生林碳积累的总成本效益（包括实施和土地机会成本）平均比人工林高60％（15.1和9.4 kgC美元^-1）。尽管与人工林相比，人工林起初显示出更高的碳储存率，但其较高的实施和土地机会成本使它们对碳耕作的成本效益较低。我们的结果进一步表明，以目前的价格水平，仅碳市场就具有有限的潜力在巴西的大西洋森林中进行大规模的恢复工作。