Department of Systematic Zoology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
CREAF, Cerdanyola del Valles, 08193 Barcelona, Catalonia, Spain.
Proc Biol Sci. 2017 Nov 15;284(1866). doi: 10.1098/rspb.2017.1784.
Masting is the highly variable production of synchronized seed crops, and is a common reproductive strategy in plants. Weather has long been recognized as centrally involved in driving seed production in masting plants. However, the theory behind mechanisms connecting weather and seeding variation has only recently been developed, and still lacks empirical evaluation. We used 12-year long seed production data for 255 holm oaks (), as well as airborne pollen and meteorological data, and tested whether masting is driven by environmental constraints: phenological synchrony and associated pollination efficiency, and drought-related acorn abscission. We found that warm springs resulted in short pollen seasons, and length of the pollen seasons was negatively related to acorn production, supporting the phenological synchrony hypothesis. Furthermore, the relationship between phenological synchrony and acorn production was modulated by spring drought, and effects of environmental vetoes on seed production were dependent on last year's environmental constraint, implying passive resource storage. Both vetoes affected among-tree synchrony in seed production. Finally, precipitation preceding acorn maturation was positively related to seed production, mitigating apparent resource depletion following high crop production in the previous year. These results provide new insights into mechanisms beyond widely reported weather and seed production correlations.
结实是高度可变性的同步种子作物生产，是植物中常见的繁殖策略。天气一直被认为是驱动结实植物种子生产的核心因素。然而，连接天气和种子变异的机制理论直到最近才得到发展，并且仍然缺乏实证评估。我们使用了长达 12 年的 255 株欧洲栓皮栎（）的种子生产数据，以及空气传播花粉和气象数据，检验了结实是否受环境限制的驱动：物候同步和相关的授粉效率，以及与干旱相关的橡子脱落。我们发现温暖的春天导致花粉季节短暂，花粉季节的长度与橡子产量呈负相关，支持物候同步假说。此外，物候同步与橡子产量之间的关系受到春季干旱的调节，环境否决对种子生产的影响取决于去年的环境限制，这意味着被动的资源储存。这两种否决都影响了种子生产中树木间的同步性。最后，在橡子成熟前的降水与种子产量呈正相关，减轻了前一年高作物产量后明显的资源枯竭。这些结果为超越广泛报道的天气和种子生产相关性的机制提供了新的见解。
