Tropical forest restoration presents a potential lifeline to mitigate climate change and biodiversity crises in the Anthropocene. Yet, the extent to which human interventions, such as tree planting, accelerate the recovery of mature functioning ecosystems or redirect successional trajectories toward novel states remains uncertain due to a lack of long‐term experiments. In 2004–2006, we established three 0.25‐ha plots at 10 sites in southern Costa Rica to test three forest restoration approaches: natural regeneration (no planting), applied nucleation (planting in patches), and plantation (full planting). In a comprehensive survey after 16–18 years of recovery, we censused >80,000 seedlings, saplings, and trees from at least 255 species across 26 restoration plots (nine natural regeneration, nine applied nucleation, eight plantation) and six adjacent reference forests to evaluate treatment effects on recruitment patterns and community composition. Both applied nucleation and plantation treatments resulted in significantly elevated seedling and sapling establishment and more predictable community composition compared with natural regeneration. Similarity of vegetation composition to reference forest tended to scale positively with treatment planting intensity. Later‐successional species with seeds ≥5 mm had significantly greater seedling and sapling abundance in the two planted treatments, and plantation showed similar recruitment densities of large‐seeded (≥10 mm) species to reference forest. Plantation tended toward a lower abundance of early‐successional recruits than applied nucleation. Trees (≥5 cm dbh) in all restoration treatments continued to be dominated by a few early‐successional species and originally transplanted individuals. Seedling recruits of planted taxa were more abundant in applied nucleation than the other treatments though few transitioned into the sapling layer. Overall, our findings show that active tree planting accelerates the establishment of later‐successional trees compared with natural regeneration after nearly two decades. While the apparent advantages of higher density tree planting on dispersal and understory establishment of larger seeded, later‐successional species recruitment is notable, more time is needed to assess whether these differences will persist and transition to the more rapid development of a mature later‐successional canopy. Our results underscore the need for ecological restoration planning and monitoring that targets biodiversity recovery over multiple decades.

中文翻译：

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积极恢复可增加树种的丰富度和 16-18 年后大种子类群的补充


热带森林恢复为缓解人类世的气候变化和生物多样性危机提供了一条潜在的生命线。然而，由于缺乏长期实验，人工干预（例如植树）在多大程度上加速了成熟功能生态系统的恢复或将演替轨迹转向新状态，仍然不确定。2004-2006 年，我们在哥斯达黎加南部的 10 个地点建立了 3 块 0.25 公顷的地块，以测试三种森林恢复方法：自然再生（不种植）、应用成核（成片种植）和人工林（完全种植）。在经过 16-18 年恢复后的全面调查中，我们普查了 26 个恢复地块（9 个自然更新、9 个应用成核、8 个人工林）和 6 个相邻参考林中至少 255 个物种的 >80,000 棵幼苗、树苗和树木，以评估处理对补充模式和群落组成的影响。与自然更新相比，应用成核和人工林处理都导致幼苗和树苗的建立率显著提高，群落组成更可预测。植被组成与参考林的相似性往往随处理种植强度呈正相关。在两种种植处理中，种子为 ≥ 5 mm 的后期演替物种的幼苗和树苗丰度显著更高，人工林表现出相似的大种子 （≥10 mm） 物种与参考林的补充密度。与应用成核相比，种植园的早期演替新兵丰度往往较低。在所有恢复处理中，树木 （≥5 cm dbh） 继续以少数早期演替物种和最初移植的个体为主。 与其他处理相比，种植类群的幼苗新兵在应用核中更丰富，尽管很少有过渡到树苗层。总体而言，我们的研究结果表明，与近二十年后的自然再生相比，主动植树加速了后期演替树木的建立。虽然更高密度的植树在分散和林下建立较大的种子、后期演替物种招募方面具有明显的优势，但需要更多时间来评估这些差异是否会持续并过渡到成熟的后期演替树冠的更快发展。我们的结果强调了生态恢复规划和监测的必要性，旨在实现数十年的生物多样性恢复。