J Plant Ecol ›› Advance articles     DOI:10.1093/jpe/rtag150

• Research Article •     Next Articles

Prolonged duration of seedling recruitment in an invasive species mediated by aerial seed banks

Zhaoren Wang1, Bomeng Wu1,2, Mengyuan Chen1, Ye Tian1, Shuanning Zheng1*   

  1. 1 State Key Laboratory of Regional and Urban Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. 2 University of Chinese Academy of Sciences, Beijing 100049, China.
    * Corresponding author: Shuanning Zheng, E-mail: snzheng@iue.ac.cn Tel: +86 592-6190771 Address: 1799 Jimei Road, Xiamen, China
  • Received:2025-09-25 Accepted:2026-05-31 Published:2026-06-30
  • Supported by:
    This work was supported by the National Natural Science Foundation of China [32401309], the National Key Research and Development Program of China [2022YFF1303202], Natural Science Foundation of Fujian Province [2023J011039], and Fujian Provincial Department of Education Grant [JAT220347].

植冠种子库对一种入侵物种幼苗建成周期的延迟机制

Abstract: Abstract Seed dormancy and dispersal time determine recruitment windows, yet their interaction in species with aerial seed banks is poorly understood. We employed Leucaena leucocephala, an invasive legume with physical dormancy (PY) and both aerial seed bank (serotiny) and soil seed banks, to investigate whether canopy retention influences PY release and to compare the persistence and their contributions in inhabitation. We combined canopy and soil seedbank monitoring, germination assays, and long-term tracking of seed bank dynamics from seed maturation to depletion in a subtropical monsoon forest. Our results show that seed lens gradually become water permeable under warm and humid treatments, leading to PY release. With delayed dispersal and canopy retention, the proportion of PY seeds declined gradually. Seeds remained in the canopy for up to 10 months, through to the following summer, during which their water permeability and dormancy release increased progressively. In contrast, soil seed banks were depleted within 5 days of post-rain dispersal under natural conditions due to rapid germination and predation, whereas artificial soil seed banks established with freshly matured seeds under predator-exclusion conditions also persisted until the following summer. PY release in both banks peaked in spring, synchronizing germination with seasonal rains. The temporal asynchrony in PY release and serotiny partitions seed depletion, minimizing predation risk, and synchronizing germination with seasonal rains, thereby promoting establishment and sustaining the invasion species L. leucocephala.

The aerial seedbank regulates the release of physical dormancy in the invasive shrub Leucaena leucocephala. By delaying seed dispersal and progressively alleviating physical dormancy, while complementing the soil seedbank, it spreads the risk of seed mortality and synchronizes germination with seasonal rainfall, thereby enhancing seedling recruitment and invasion success.

Key words: Aerial seedbank, Legume, Leucaena leucocephala, Physical dormancy, Seed germination, Soil seedbank

摘要:
种子传播和休眠共同决定植物幼苗更新的时间窗口,但对于具有植冠种子库的物种,二者的协同作用机制尚不明确。本研究以兼具植冠与土壤种子库的豆科入侵植物银合欢为对象,通过野外幼苗建成的全周期动态监测、萌发试验及幼苗追踪,探究冠层宿存对物理休眠的调控作用,以及两类种子库的存续特征对种群定殖的影响。结果表明,种子在植冠种子库和去除动物捕食的土壤种子库中,均可维持至次年夏季。在冠层滞留的10个月,种子物理休眠持续释放。但降水触发种子落地后,种子快速萌发,叠加动物捕食干扰,传播后5日内快速耗尽。室内控制实验进一步证实,兼具高温高湿的环境下种子吸水位点的透水性增强,是破除其物理休眠的关键。同时,两类种子库的物理休眠释放高峰均出现在春季,使种子萌发窗期与季节性降雨节律同步。休眠释放与植冠种子的延迟扩散的时间分化,既降低了种子集中消亡风险,又使幼苗出土时机与雨季节律匹配,从而提升建植成功率,为银合欢种群持续拓殖提供了关键优势。

关键词: 植冠种子库, 豆科植物, 银合欢, 物理休眠, 种子萌发, 土壤种子库