Royal Botanic Gardens Kew, Wellcome Trust Millennium Building, Wakehurst, West Sussex, RH17 6TN, UK.
Ecology and Conservation Biology, Institute of Plant Sciences, University of Regensburg, Universitätsstrasse 31, Regensburg, 93040, Germany.
Ecol Lett. 2020 Nov;23(11):1635-1642. doi: 10.1111/ele.13595. Epub 2020 Sep 2.
Seed movement and delayed germination have long been thought to represent alternative risk-spreading strategies, but current evidence covers limited scales and yields mixed results. Here we present the first global-scale test of a negative correlation between dispersal and dormancy. The result demonstrates a strong and consistent pattern that species with dormant seeds have reduced spatial dispersal, also in the context of life-history traits such as seed mass and plant lifespan. Long-lived species are more likely to have large, non-dormant seeds that are dispersed far. Our findings provide robust support for the theoretical prediction of a dispersal trade-off between space and time, implying that a joint consideration of risk-spreading strategies is imperative in studying plant life-history evolution. The bet-hedging patterns in the dispersal-dormancy correlation and the associated reproductive traits have implications for biodiversity conservation, via prediction of which plant groups would be most impacted in the changing era.
种子传播和延迟发芽长期以来被认为代表了两种风险扩散策略，但目前的证据只涵盖了有限的范围，且结果不一。在这里，我们首次在全球范围内检验了扩散和休眠之间的负相关关系。结果表明，具有休眠种子的物种的空间扩散减少了，这在种子质量和植物寿命等生活史特征的背景下也是如此。寿命长的物种更有可能拥有大的、非休眠的种子，并且这些种子可以传播得更远。我们的研究结果为空间和时间之间的扩散权衡的理论预测提供了强有力的支持，这意味着在研究植物生活史进化时，必须同时考虑风险扩散策略。在扩散-休眠相关性和相关繁殖特征中的避险模式，对生物多样性保护具有重要意义，因为可以预测在变化的时代中哪些植物群体将受到最大的影响。
