Restoring valuable timber trees is a necessary part of regaining many ecosystem services and products provided by degraded tropical forests. However, knowledge of seed production, a regeneration prerequisite, is limited for many tropical timber tree species. We studied the fruit production of African mahogany (Khaya anthotheca) in a semi-deciduous rainforest in East Africa, to provide information for ecological restoration programs. First, we quantified population variability and synchrony in fruit production. Then, we assessed how reproductive status and output were influenced by tree size, neighbourhood crowding, exchangeable cations, liana presence, and crown exposure. We found fruit production at the population level was weakly synchronised, with high interannual variability at the population and individual levels. Tree size determined reproductive status. Individual quantity of fruit produced increased with tree size but decreased with neighbourhood crowding. Our results indicate that K. anthotheca does not meet the criteria for mast fruiting. Our findings suggest that reproductive output in mahogany is regulated by tree size and competition. In addition to active protection, thinning to reduce competition around seed trees may boost fruit production at the individual tree level to provide seed for forest enrichment.

中文翻译：

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东非半落叶雨林中非洲桃花心木（Khaya anthotheca）果实产量的种内变异

恢复有价值的用材树木是恢复退化热带森林提供的许多生态系统服务和产品的必要组成部分。然而，对于许多热带用材树种来说，作为再生先决条件的种子生产知识是有限的。我们研究了东非半落叶雨林中非洲桃花心木（ Khaya anthotheca ）的果实生产，为生态恢复计划提供信息。首先，我们量化了水果生产中的种群变异性和同步性。然后，我们评估了树木大小、邻近拥挤、可交换阳离子、藤本植物的存在和树冠暴露对繁殖状态和产量的影响。我们发现人口层面的水果生产同步性较弱，人口和个体层面的年际变化较大。树木的大小决定了繁殖状况。个体生产的果实数量随着树木大小的增加而增加，但随着邻近区域的拥挤而减少。我们的结果表明K. anthotheca不符合肥大结果的标准。我们的研究结果表明，桃花心木的繁殖产量受树木大小和竞争的调节。除了积极保护之外，间伐以减少种子树周围的竞争可能会提高单棵树的果实产量，为森林富集提供种子。