Climate and synchrony with conspecifics determine the effects of flowering phenology on reproductive success in <i>Silene acaulis</i>

Changes in flowering phenology resulting from climate change could impact individual plant fitness and population viability. Flowering phenology can mediate plant reproductive success in several ways, including pollinator interactions, flowering synchrony with conspecifics, and timing of suitable abiotic conditions. We explored factors that control phenology and reproductive success for an alpine cushion plant, <i>Silene acaulis</i>, across two years and four sites, totaling 1,123 plants, in Colorado, USA. We investigated relationships between flowering time, flowering synchrony, and reproductive success with local abiotic conditions and pollinator behavior. Mean flowering phenology was strongly correlated with the timing of snowmelt across sites and years. Relative to mean flowering times, earlier flowering plants generally produced more flowers and experienced greater soil moisture during flowering but reduced synchrony with conspecifics. Fruit set tended to increase with greater soil moisture, synchrony during flowering, and earlier flowering times. Pollinator visitation increased with local <i>Silene</i> flower density. Earlier snowmelt and drier conditions later in the season favor earlier flowering, but these effects are partially counteracted by the positive effects of synchrony, perhaps because of changes in pollinator visitation. Overall, while both biotic and abiotic effects influence reproductive success, late-season drought may outweigh the benefits of flowering synchrony to increasingly favor earlier flowering.气候变化引发的开花物候变化，可能会对植物个体适合度与种群存续能力造成影响。开花物候可通过多种途径调控植物的生殖成功，包括传粉者互作、与同种个体的开花同步性，以及适宜非生物条件的出现时机。本研究以美国科罗拉多州的高山垫状植物——无茎蝇子草（Silene acaulis）为研究对象，在两年时间内的四个样地中开展实验，共计调查1123株植株，探究了调控该物种物候与生殖成功的相关因子。我们进一步分析了开花时间、开花同步性与生殖成功同当地非生物环境条件及传粉者行为之间的关联。结果显示，不同样地与年份的平均开花物候，与融雪时间呈显著相关。相较于平均开花时间，开花较早的植株通常能产生更多花朵，且开花时段的土壤含水量更高，但与同种个体的开花同步性会有所降低。坐果率往往随土壤含水量升高、开花同步性提升以及开花时间提前而升高。传粉者访花频次随当地无茎蝇子草的花朵密度升高而增加。融雪时间提前与季末干旱条件，会促使植株提前开花，但同步性带来的正向效应会部分抵消这一影响，这可能与传粉者访花的变化有关。总体而言，尽管生物与非生物因子共同影响植物生殖成功，但季末干旱的效应可能超过开花同步性带来的益处，进而愈发倾向于推动植株提前开花。

搜集汇总

背景与挑战

背景概述

该数据集研究了高山垫状植物Silene acaulis的开花物候与繁殖成功的关系，重点关注气候和同种开花同步性的影响。研究基于美国科罗拉多州两个年份和四个地点的1,123株植物数据，发现开花时间与融雪时间强相关，较早开花可能增加花数但减少同步性，而繁殖成功受土壤湿度、同步性和开花时间共同影响。结论表明，晚季干旱可能促使植物更早开花以应对气候变化。