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较为匮乏。本研究旨在对喀麦隆、刚果及中非共和国11个样地内的31种主要用材树种的繁殖径级进行量化分析。具体而言，本研究探究了四个核心问题：(1) 树种间的繁殖径级差异是否可通过7个物种性状组合加以解释；(2) 同一树种的繁殖径级是否在不同样地间存在变异；(3) 树木的繁殖状态是否随冠层暴露度变化而改变；(4) 各国林业法规设定的最小采伐径限（minimum cutting diameter limits, MCDL）能否保障采伐后母树种群的存续。
与其他热带地区的同类研究结果一致，本研究发现不同用材树种的繁殖径级存在显著变异，且该变异与树种成年树体特征（最大胸径与树高）显著相关。部分树种的繁殖径级阈值在不同样地间存在显著差异，同时冠层暴露度对树木繁殖状态具有显著的正向影响。
多数树种的最小采伐径限设置较为合理，达到该径级的树木具备较高的母树存续概率。
作为中非地区针对用材树种繁殖个体大小最全面的评估研究，本研究对生产林可持续经营具有重要指导意义，同时指出了部分树种的最小采伐径限设置存在不合理之处，以及不同样地间繁殖径级存在变异的问题。
本研究同时强调，需要对涵盖多种生态策略的树种开展长期物候监测，以解答物种生活史、资源分配权衡等理论问题，以及最小采伐径限设置等实际应用问题。