Data from: The size at reproduction of canopy tree species in central Africa

Size at reproduction is a key aspect of species life history that has been little explored for long-lived tropical trees. In this study, we aimed to quantify reproductive diameter for 31 major timber species across 11 sites in Cameroon, Congo, and Central African Republic. Specifically, we examined (1) whether between-species variability can be explained by a set of seven species traits; (2) whether reproductive diameter varied within-species among sites; (3) whether reproductive status varied with crown exposure; and (4) whether the minimum cutting diameter limits (MCDL) imposed by national forest regulations enable the persistence of seed trees after logging operations. In accordance with studies conducted elsewhere in the tropics, we found a great variability in diameter at reproduction among species that was correlated with adult stature (maximum diameter and height). For some species, reproductive diameter thresholds showed substantial variation between sites, and crown exposure had a significant positive effect on reproductive status. The majority of MCDLs was found to be suitable, trees having high probability for being seed trees at MCDL. As the most complete assessment of size at reproduction for timber species in central Africa, the study has implications for the sustainable management of production forests, highlighting questionable MCDL for some species and between-site variation in reproductive diameter. The study also highlighted the need for long-term phenological monitoring of tree species spanning a large range of ecological strategies to address both theoretical (species life-history, allocation trade-offs) and practical questions (MCDL).繁殖个体大小（size at reproduction）是物种生活史的关键特征之一，但针对长寿热带树木的相关研究仍鲜有开展。本研究旨在量化喀麦隆、刚果以及中非共和国11个样地内31种主要用材树种的繁殖直径（diameter at reproduction）。具体而言，我们开展了四项研究：(1) 物种间的繁殖直径差异是否可通过7项物种功能性状予以解释；(2) 同一物种的繁殖直径是否存在样地间变异；(3) 繁殖状态是否随冠层暴露度（crown exposure）发生变化；(4) 国家森林法规设定的最小采伐直径限制（minimum cutting diameter limits, MCDL）能否保障采伐作业后留种母树的种群存续。 与其他热带地区的同类研究结果一致，本研究发现不同树种的繁殖直径存在显著差异，且与成年植株体型（最大直径与树高）呈显著相关。部分树种的繁殖直径阈值在不同样地间存在显著变异，冠层暴露度对繁殖状态具有显著的正向影响。多数最小采伐直径限制设置较为合理，达到该直径阈值的树木具备成为留种母树的高概率。 作为中非地区针对用材树种繁殖个体大小最为全面的评估研究，本研究对生产性森林的可持续经营具有重要指导意义：研究指出部分树种的最小采伐直径限制存在合理性争议，且繁殖直径存在样地间变异。此外，本研究还强调，需针对涵盖多种生态策略的树种开展长期物候监测，以解决物种生活史、资源分配权衡等理论问题，以及最小采伐直径限制相关的实践问题。