Fernández-Pascual Eduardo, Carta Angelino, Mondoni Andrea, Cavieres Lohengrin A, Rosbakh Sergey, Venn Susanna, Satyanti Annisa, Guja Lydia, Briceño Verónica F, Vandelook Filip, Mattana Efisio, Saatkamp Arne, Bu Haiyan, Sommerville Karen, Poschlod Peter, Liu Kun, Nicotra Adrienne, Jiménez-Alfaro Borja
Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, Oviedo/Uviéu, Spain.
Dipartimento di Biologia, Botany Unit, University of Pisa, Pisa, 56126, Italy.
New Phytol. 2021 Mar;229(6):3573-3586. doi: 10.1111/nph.17086. Epub 2020 Dec 24.
Assumptions about the germination ecology of alpine plants are presently based on individual species and local studies. A current challenge is to synthesise, at the global level, the alpine seed ecological spectrum. We performed a meta-analysis of primary data from laboratory experiments conducted across four continents (excluding the tropics) and 661 species, to estimate the influence of six environmental cues on germination proportion, mean germination time and germination synchrony; accounting for seed morphology (mass, embryo : seed ratio) and phylogeny. Most alpine plants show physiological seed dormancy, a strong need for cold stratification, warm-cued germination and positive germination responses to light and alternating temperatures. Species restricted to the alpine belt have a higher preference for warm temperatures and a stronger response to cold stratification than species whose distribution extends also below the treeline. Seed mass, embryo size and phylogeny have strong constraining effects on germination responses to the environment. Globally, overwintering and warm temperatures are key drivers of germination in alpine habitats. The interplay between germination physiology and seed morphological traits further reflects pressures to avoid frost or drought stress. Our results indicate the convergence, at the global level, of the seed germination patterns of alpine species.
目前，关于高山植物萌发生态学的假设是基于个别物种和局部研究得出的。当前的一个挑战是在全球层面综合高山种子生态谱。我们对来自四大洲（不包括热带地区）的661个物种的实验室实验原始数据进行了荟萃分析，以估计六种环境线索对萌发比例、平均萌发时间和萌发同步性的影响；同时考虑种子形态（质量、胚：种子比）和系统发育。大多数高山植物表现出生理种子休眠，对冷层积处理有强烈需求，萌发需要温暖环境线索，对光照和变温有正向萌发反应。局限于高山带的物种比分布范围也延伸至林线以下的物种对温暖温度有更高偏好，对冷层积处理的反应更强。种子质量、胚大小和系统发育对萌发的环境响应有很强的制约作用。在全球范围内，越冬和温暖温度是高山生境中萌发的关键驱动因素。萌发生理学与种子形态特征之间的相互作用进一步反映了避免霜冻或干旱胁迫的压力。我们的结果表明，在全球层面，高山物种的种子萌发模式具有趋同性。
