Data from: The individual and combined effects of snowmelt timing and frost exposure on the reproductive success of montane forbs

1. Changes from historic weather patterns have affected the phenology of many organisms worldwide. Altered phenology can introduce organisms to novel abiotic conditions during growth and modify species interactions, both of which could drive changes in reproduction. 2. We explored how climate change can alter plant reproduction using an experiment in which we manipulated the individual and combined effects of snowmelt timing and frost exposure, and measured subsequent effects on flowering phenology, peak flower density, frost damage, pollinator visitation, and reproduction of four subalpine wildflowers. Additionally, we conducted a pollen supplementation experiment to test whether the plants in our snowmelt and frost treatments were pollen limited for reproduction. The four plants included species flowering in early spring to mid-summer. 3. The phenology of all four species significantly advanced and the bloom duration was longer in the plots from which we removed snow, but with species-specific responses to snow removal and frost exposure in terms of frost damage, flower production, pollinator visitation, and reproduction. The two early-blooming species showed significant signs of frost damage in both early-snowmelt and frost treatments, which negatively impacted reproduction for one of the species. Further, we recorded fewer pollinators during flowering for the earliest-blooming species in the snow removal plots. We also found lower fruit and seed set for the early-blooming species in the snow removal treatment, which could be attributed to the plants growing under unfavorable abiotic conditions. However, the later-blooming species escaped frost damage even in the plots where snow was removed, and experienced increased pollinator visitation and reproduction. 4. Synthesis. This study provides insight into how plant communities could become altered due to changes in abiotic conditions, and some of the mechanisms involved. While early-blooming species may be at a disadvantage under climate change, species that bloom later in the season may benefit from early snowmelt, suggesting that climate change has the potential to reshape flowering communities.1. 全球范围内，历史天气模式的改变已影响到众多生物的物候学（phenology）。物候改变会使生物在生长阶段暴露于全新的非生物环境（abiotic conditions）中，并改变物种间的相互作用，这两者均可能推动繁殖过程发生变化。 2. 本研究通过操控融雪时间（snowmelt timing）与霜冻暴露（frost exposure）的单独及联合效应开展实验，探究气候变化如何影响植物繁殖，并测定了其对4种亚高山野花（subalpine wildflowers）的开花物候学（flowering phenology）、开花峰值密度、霜冻损伤（frost damage）、传粉者访花（pollinator visitation）以及繁殖状况的后续影响。此外，我们开展了花粉补充实验（pollen supplementation experiment），以检验融雪与霜冻处理组中的植物是否因繁殖受到花粉限制（pollen limited）。本次研究的4种植物涵盖了从早春至仲夏开花的类群。 3. 在移除积雪的样地中，4个物种的物候均显著提前，花期也更长；但在霜冻损伤、花量、传粉者访花及繁殖表现上，各物种对积雪移除与霜冻暴露的响应存在物种特异性。两种早春开花物种（early-blooming species）在提前融雪与霜冻处理中均表现出明显的霜冻损伤症状，其中一个物种的繁殖因此受到负面影响。此外，在积雪移除样地中，开花最早的物种的传粉者访花频次更低。我们还发现，积雪移除处理下的早春开花物种坐果率与结籽率（fruit and seed set）更低，这可能是因为植株生长在不利的非生物环境中。而晚开花物种（late-blooming species）即便在积雪移除样地中也能避开霜冻损伤，且传粉者访花频次与繁殖表现均有所提升。 4. 研究结论：本研究揭示了非生物环境改变如何影响植物群落，以及其中涉及的部分机制。尽管早春开花物种在气候变化下可能处于劣势，但季末晚开花物种或可从提前融雪中获益，这表明气候变化有可能重塑开花植物群落结构。